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Choice Multiple Section 3.2 1. Which one of the following is an SI base unit? a. dyne b. newton c. milliliter d. ampere e. joule Section 3.2 2. The kilo is a. a unit of mass b. a unit employed in medical terminology c. a decimal multiplier in the metric system d. a unit of speed e. a volume unit employed by the DEA (drug enforcement agency) Section 3.2 3. The SI base units of temperature and mass respectively are a. degree and gram b. kelvin and kilogram c. celsius and milligram d. oK and kilogram e. kelvin and gram Section 3.2 6. The boiling point of barium is 725 oC. Determine the equivalent value in oF a. 435 oF b. 1337 oF c. 1247 oF d. 1362 oF e. 1273 oF Section 3.2 7. The melting point of antimony is listed in one handbook as 630.74 oC. Determine the equivalent value in oF a. 382.41 oF b. 1103.3 oF c. 1077.7 oF d. 1167.3 oF e. 1192.9 oF Section 3.2 8. On a day in the summer of 1992, the temperature fell from 98 oF to 75 oF in just three hours. The temperature drop expressed in celsius degrees (Co) was a. 13 Co b. 41 Co c. 45 Co d. 9 Co e. 75 Co Section 3.2 9. On a day in the summer of 1976, the temperature fell from 95 oF to 75 oF in just three hours. The temperature drop expressed in celsius degrees (Co) was a. 11 Co b. 13 Co c. 18 Co d. 20 Co e. -12 Co Section 3.2 10. The melting point of antimony was listed in one handbook as 1167.3 oF. Expressed in kelvins this temperature would be a. 357.6 K b. 496.8 K c. 583.7 K d. 894.2 K e. 903.9 K Section 3.4 16. An electronic scale used in the mailroom is calibrated (and displays) in tenths of a kilogram from 1 to 140 kg. Determine how many significant figures should be used to express the mass of anyone using the scale whose mass is between 80.2 and 83.5 kg. a. 3 b. 5 c. 4 d. 2 e. 1 Section 3.4 17. Which response gives the correct number of significant figures for all three of the following meas-urements? #1) 7.103 cm #2) 0.00005 inch #3) 1.3400 x 10-4 dm3 a. 3, 5, and 4 b. 3, 1, and 3 c. 4, 1, and 3 d. 4, 1, and 5 e. 4, 5, and 5 40 Section 3.4 18. After evaluating the expression, 221.8027.0726.13+ how many significant figures should be displayed in the result? a. 1 b. 2 c. 3 d. 4 e. 5 Section 3.4 19. How many significant figures should there be in result of the operation, 8.5201 + 1.93? a. 1 b. 2 c. 3 d. 4 e. 5 Section 3.4 20. When the expression, 412.272 + 0.00031 - 1.00797 + 0.000024 + 12.8, is evaluated, the result should be expressed as a. 424 b. 424.0 c. 424.1 d. 424.06 e. 424.064364 Section 3.4 21. When the expression, 16.0200 + 0.00048 - 11.184 - 221.1, is evaluated, the result should be ex-pressed as a. -216.3 b. -216.26 c. -216.2635 d. -216.26352 e. -2.2 x 102 Section 3.4 22. One radio station operates on an assigned frequency of 96.3 megahertz while another one operates on an assigned frequency of 1280 kilohertz. What is the ratio of the larger to the smaller value? a. 13.3 b. 13.29 41 c. 75.2 d. 75.23 e. 13.2918 Section 3.4 23. When a student evaluates the expression, 0.654293.30x0.082057x0.04616 the result should be expressed as a. 1.69 b. 1.70 c. 1.699 d. 1.6987 e. 1.69870 Section 3.4 24. When a student evaluates the expression 2.688x760.0744.6373.15x0.082057x4.268 the result should be expressed as a. 49.623 b. 49.631 c. 49.62 d. 49.63 e. 49.623202 Section 3.4 26. The number, 0.0030600, is properly expressed in scientific notation as a. 3.0600 x 10-2 b. 0.30600 x 10-2 c. 0.306 x 10-2 d. 3.06 x 10-3 e. 3.0600 x 10-3 Section 3.4 27. The number, 0.02100, is properly expressed in scientific notation as a. 0.21 x 10-1 b. 2.1 x 10-2 c. 2.100 x 10-2 d. 21.0 x 10-3 e. 2.10 x 10-2 42 Section 3.5 28. The SI prefixes giga and micro represent, respectively: a. 109 and 10-6 b. 10-9 and 10-6 c. 106 and 10-3 d. 103 and 10-3 e. 10-9 and 10-3 Section 3.5 29. The SI prefixes mega and nano represent, respectively: a. 109 and 10-6 b. 10-6 and 109 c. 106 and 10-9 d. 106 and 109 e. 10-6 and 10-9 Section 3.5 30. A distance of 18 x 10-3 meters is numerically equivalent to a. 1.8 micrometers b. 1.8 millimeters c. 0.18 meters d. 1.8 centimeters e. 18 kilometers Section 3.5 31. The diameter of an atom was determined and a value of 2.35 x 10-8 cm was obtained. How many nanometers is this? a. 2.35 x 101 nm b. 2.35 x 10-19 nm c. 2.35 x 10-15 nm d. 2.35 x 10-1 nm e. 2.35 x 10-10 nm Section 3.5 32. How many micrometers are there in 3.672 km? a. 3.672 x 106 b. 2.723 x 10-7 c. 2.723 x 10-4 d. 3.672 x 109 e. 3.672 x 103 43 Section 3.5 34. How many cm3 are there in 0.00424 dm3? a. 0.0424 cm3 b. 0.424 cm3 c. 4.24 cm3 d. 0.00000424 cm3 e. 424 cm3 Section 3.5 35. How many cubic inches are in 1.00 dm3? 1 in = 2.54 cm. a. 61.0 in3 b. 155 in3 c. 394 in3 d. 1.64 x 104 in3 e. 383 x 102 in3 Section 3.5 36. The average distance from the earth to the sun is 9.30 x 107 miles. Light travels at a speed of 3.00 x 108 meters per second. If the sun were to be suddenly extinguished, how long would it take for the effect to be visible here on the earth? a. 8.32 seconds b. 5.38 minutes c. 0.499 seconds d. 8.32 minutes e. 0.310 seconds Section 3.5 37. Which one of the following represents the smallest distance? a. 4.5 mm b. 0.20 inch c. 0.83 cm d. 0.73 m e. 0.30 yard Section 3.5 38. How many square meters are there in a rectangular piece of carpet which measures 12.0 feet by 22.0 feet? 1 m = 39.37 in, 1 ft = 12 in. a. 24.5 m2 b. 28.4 m2 c. 866 m2 d. 80.5 m2 e. 966 m2 44 Section 3.5 41. An empty volumetric flask, weighing 60.42 grams, weighed 309.60 grams when filled with water. After emptying the water and drying the flask, it was filled with ethylene glycol. It now weighed 338.72 grams. What is the specific gravity of the ethylene glycol? a. 0.8048 b. 0.9140 c. 1.094 d. 1.1169 e. 1.2424 Section 3.5 42. A number resulting from a measurement was properly expressed in scientific notation as 3.170 x 10-2 meters (m). The number could also be correctly written as a. 0.0317 m b. 0.03170 m c. 0.032 m d. 317 m e. 317.0 m Section 3.5 43. The density of cadmium metal is 8.642 g/cm3. Given that 1 foot(ft) = 12 inches(in), 1 in = 2.54 cm, and 1 pound (lb) = 453.6 g, what is the density of cadmium in lb/ft3? a. 17.70 lb/ft3 b. 212.4 lb/ft3 c. 263.4 lb/ft3 d. 539.5 lb/ft3 e. 5535 lb/ft3 Section 3.5 44. The density of chromium metal is 7.20 g/cm3. Given that 1 foot(ft) = 12 inches(in), 1 in = 2.54 cm, and 1 pound (lb) = 453.6 g, what is the density of chromium in lb/ft3? a. 14.7 lb/ft3 b. 177 lb/ft3 c. 449 lb/ft3 d. 459 lb/ft3 e. 599 lb/ft3 Section 3.6 47. An empty volumetric flask, weighing 27.16 grams, has a volume of 100.4 cm 3. How much would it weigh when filled with bromine (a liquid element) which has a density of 3.1028 g cm-3? a. 59.51 g b. 284.4 g 45 c. 311.5 g d. 338.7 g e. 395.8 g Section 3.6 49. How many cm3 of water will overflow from a full container of water if a 66.7 gram sample of vana-dium (density = 6.11 g cm-3) is carefully placed in the container so there is no splashing, just over-flowing? a. 11.9 cm3 b. 9.92 cm3 c. 60.6 cm3 d. 10.9 cm3 e. 0.0916 cm3 Section 3.6 50. A sample of zinc metal (density = 7.14 g cm-3) was submerged in a graduated cylinder containing water. The water level rose from 162.5 cm3 to 186.0 cm3 when the sample was submerged. How many grams did the sample weigh? a. 168 g b. 22.7 g c. 26.1 g d. 48.8 g e. 3.29 g Section 3.6 51. A sample of an alloy (density = 9.62 g cm -3) was submerged in a graduated cylinder containing wa-ter. The water level rose from 166.5 cm3 to 182.0 cm3 when the sample was submerged. How many grams did the sample weigh? a. 0.621 g b. 175 g c. 18.9 g d. 17.8 g e. 149 g Section 3.6 52. A compound, once named "Isooctane" and used as a fuel in gasoline engines because it had an anti-knock octane rating of 100, has a density of 0.6919 g cm -3. How many pounds would 20.4 gallons of this fuel (a typical full tank) weigh? 1 gallon = 3785 cm 3 = 4 quart; 1 pound = 453.6 g a. 77.2 pounds b. 246 pounds c. 118 pounds d. 24.2 pounds e. 50.6 pounds 46 Section 3.6 61. A 55.25 gallon container was filled with an industrial solvent whose density is 1.146 g/cm3. How many kg should the solvent in the container weigh? 1 gallon(gal) = 3.785 liters(L) a. 24.32 kg ! b. 239.7 kg c. 243.2 kg d. 2.397 x 102 kg e. 552.5 kg Fill in the Blanks Section 3.2 64. Many home freezers maintain a temperature of 0.0 oF. Express this temperature in oC. ______ () Section 3.4 65. How many significant digits are there in the number 1.050 x 109? ______ () Section 3.4 66. Express the result of the operation, 8.520 + 2.7, to the proper number of significant digits. ______ ( ) Section 3.4 67. How many significant figures does the number 30.340 contain? ______ ( ) Section 3.5 68. What will be the cost, in dollars, of gasoline for a 3170 mile trip in a car pulling a trailer that delivers 13.30 miles per gallon, if the average price of gas is $1.449 cents per gallon? ______ () Section 3.5 71. A 201 g sample weighs ______ mg. () Section 3.5 72. A spot on a microchip which is 7500 nm (nanometers) in diameter is ______ pm (picometers) in diameter. () Section 3.5 73. An object weighing 450 kg, expressed in megagrams (Mg), is ______ Mg. () 47 Section 3.6 74. Carbon tetrachloride, a colorless liquid, has a density of 1.5867 g cm-3 at 25.0 oC and a freezing point of -22.9 oC, while water has a density of 0.99704 g cm-3 at 25.0 oC and a freezing point of 0.00 oC What is the specific gravity of carbon tetrachloride? ______ () True and False Section 3.4 76. A large crowd attending a bicentennial celebration in a metropolitan area was described as 450,000 in the morning newspaper the next day. A chemistry student stated that, mindful of the purpose of using scientific notation, this should be correctly expressed in scientific notation as 4.50000 x 105. Does the number expressed this way truly represent the crowd estimate, true or false? ___ () Section 3.4 77. Any number known accurately to six or more significant digits is defined as an exact number. ___ () Section 3.4 79. The ambiguity in the precision of a number being expressed can be eliminated by proper use of sci-entific notation. ___ () Section 3.4 80. The result of the following operation, 8.52010 x 7.9, should be expressed as 67.3088. ___ () Section 3.5 81. A 15 km distance run is a shorter run than a 10 mile distance run. ___ () Section 3.5 82. A 5.00 pound bag of sugar weighs more than a 2.50 kg bag of sugar. ___ () Section 3.5 83. A piece of carpet which measures 44.0 square yards is smaller that a piece of carpet which measures 44.0 square meters. ___ () Section 3.5 84. A liter of carbon tetrachloride is a smaller quantity than a quart of the same substance. ___ () Section 3.5 85. An increase of one kelvin in temperature is a smaller change than an increase of one degree Fahren-heit. ___ () Section 3.6 86. Specific gravity equals (mass/volume) divided by time. ___ () Critical Thinking Section 3.4 87. A number resulting from a measurement was properly expressed in scientific notation as 2.1 x 10-3 meters (m). The number could also be correctly written as 48 a. 0.0021 m b. 0.002100 m c. 0.00021 m d. 2.1000 m e. 21000 m Section 3.6 95. Iron has a density of 7.86 g cm -3. As part of their exam, students in the junior class at a boarding school were to weigh a metal sphere, measure its diameter and calculate its density. Some of the seniors sneaked into the lab the weekend before, took the iron sphere, took it downtown, and had the interior partially hollowed and the surface repaired so it wouldn't be noticed and replaced it in the cabinet late on Sunday. The junior students who had this iron sphere for their "unknown" obtained 9.30 cm for the diameter and 2.44 kg for the mass. What value should they have reported for the mass of the sphere if it had not been tampered with, and what was the volume of the hollowed out space in the interior of the sphere? )r(34volume3 ___________________ () 49 The Mole: Connecting the Macroscopic and Molecular Worlds Multiple Choice Section 4.1 2. The formula mass of C14H28(COOH)2 is a. 242.40 u b. 254.41 u c. 270.41 u d. 273.39 u e. 286.41 u Section 4.1 4. The formula mass of (NH4)3PO4 is a. 116.03 u b. 121.07 u c. 149.09 u d. 155.42 u e. 242.01 u Section 4.2 5. How many moles of 12C are there in a 3.50 g sample of this substance? a. 0.291 moles b. 0.292 moles c. 1.00 moles d. 3.43 moles e. 3.50 moles Section 4.2 10. The atomic weight of helium is 4.0026 u. What is the mass of a helium sample which contains 0.427 moles of He gas? a. 0.427 g b. 0.107 g c. 1.71 g d. 2.57 g e. 9.37 g Section 4.2 13. The atomic weight of phosphorus is 30.974 u. What is the mass of a phosphorus sample which contains 0.585 moles of phosphorus atoms? a. 17.3 g b. 18.1 g c. 22.3 g d. 26.5 g e. 34.2 g 58 Section 4.2 15. How many atoms of 12C are there in a 3.50 gram sample of this particular isotope? a. 1.72 x 1023 b. 1.76 x 1023 c. 2.07 x 1024 d. 2.11 x 1024 e. 8.01 x 1023 Section 4.3 19. A sample of (N2H5)2C3H4O4 contains 1.084 x 1024 carbon atoms. How many moles of hydrogen atoms are there in the same sample? Avogadros number = 6.022 x 1023. a. 4.200 moles b. 4.725 moles c. 7.000 moles d. 8.400 moles e. 2.400 moles Section 4.2 22. A sample of arabinose, C5H10O5, contains 0.6000 moles of the substance. How many carbon atoms are there in the sample? a. 3 b. 5 c. 3.613 x 1023 d. 1.807 x 1024 e. 3.011 x 1024 Section 4.2 24. The mass of 5.20 moles of glucose, C6H12O6, is correctly expressed as a. 1.56 x 10-21 g b. 31.2 g c. 34.7 g d. 937 g e. 6.43 x 1020 g Section 4.2 25. How many molecules of carbon dioxide are there in 154.0 grams of carbon dioxide? a. 3.499 b. 2.107 x 1024 c. 4.214 x 1024 d. 9.274 x 1025 e. 4.081 x 1027 59 Section 4.3 29. A sample of C12H22O11, contains 0.4662 moles of carbon atoms. How many moles of hydrogen atoms (H) are there in the sample? a. 0.2543 moles b. 0.4662 moles c. 10.26 moles d. 0.8547 moles e. 0.9324 moles Section 4.4 34. What is the percent, by weight, of chromium in K 2CrO4, to the proper number of significant digits? Use the atomic weights provided which come from your text! a. 26.776 % b. 31.763 % c. 40.268 % d. 42.241 % e. 51.996 % Section 4.4a 52. A 4.266 gram sample of a hydrocarbon, upon combustion in a combustion analysis apparatus, yielded 5.672 grams of water. The percent, by weight, of hydrogen in the hydrocarbon is therefore: a. 7.44 % b. 8.62 % c. 14.88 % d. 17.24 % e. 20.07 % Section 4.4a 54. A 6.789 gram sample of a compound was analyzed for nitrogen in a nitrogen analysis apparatus. In the procedure, all the nitrogen present was completely converted to ammonia (NH3). 1.637 grams of ammonia were obtained. The percent, by weight, of nitrogen in the compound is therefore: a. 35.57 % b. 24.11 % c. 75.89 % d. 31.77 % e. 19.83 % Section 4.7 71. The left side of a balanced chemical equation is shown below, K2Cr2O7 + 4 H2SO4 + 3 SeO2 . . . 60 61 If 0.600 moles of K2Cr2O7, 2.800 moles of H2SO4 and 1.500 moles of SeO2 are brought together and allowed to react, then a. H2SO4 is the limiting reagent b. K2Cr2O7 is the limiting reagent c. there are 1.300 moles of H2SO4 in excess d. there are 0.100 moles of K2Cr2O7 in excess e. there are 0.300 moles of SeO2 in excess Section 4.7 77. Thermal decomposition of KClO3(s) yields KCl(s) and O2(g). When 4.289 grams of KClO3 (0.03500 moles) undergo this reaction, how many grams of oxygen are produced? a. 1.120 grams b. 0.5601 grams c. 2.240 grams d. 1.680 grams e. 4.288 grams True and False Section 4.2 101. A mole of oxygen, O2, and a mole of phosphorus, P4, do not contain the same number of molecules. ___ ( ) Critical Thinking Section 4.4 109. In a quantitative analysis study, 4.624 grams of a compound containing carbon, hydrogen, and oxy-gen only yielded 7.210 g of CO2 and 2.656 g of H2O in a combustion analysis apparatus. Determine the empirical formula of the compound. a. C9H16O8 b. C10H18O9 c. C11H20O10 d. C12H22O11 e. C13H24O12 Reactions Between Ions in Aqueous Solutions Multiple Choice Section 5.1 1. A solution is sitting undisturbed on a side shelf in the laboratory. A small crystal of the same solute of which the solution is made was gently dropped into the quiet solution. Suddenly, a mass of crys-tals formed and settled to the bottom of the container. The solution is, or must have been a. dilute b. concentrated c. unsaturated d. saturated e. supersaturated Section 5.2 2. Which one of the following is a nonelectrolyte? a. aqueous barium nitrate solution b. aqueous calcium chloride solution c. aqueous lithium phosphate solution d. aqueous methyl alcohol solution e. aqueous potassium sulfate solution Section 5.2 3. Which one of the following is an electrolyte? a. aqueous maple syrup solution b. aqueous calcium chloride solution c. aqueous sucrose solution d. aqueous acetone solution e. aqueous ethyl alcohol solution Section 5.2 4. Which one of the following is an electrolyte? a. aqueous glucose solution b. aqueous acetone solution c. aqueous ethylene glycol solution d. aqueous methyl alcohol solution e. aqueous potassium sulfate solution 83 Section 5.2 5. Which one of the following is a nonelectrolyte? a. aqueous ammonium chloride solution b. aqueous ethylene glycol solution c. aqueous nickel sulfate solution d. aqueous sodium perchlorate solution e. aqueous zinc nitrate solution Section 5.2 6. Given the following set of solutions A: aqueous sodium perchlorate B: aqueous methyl alcohol C: aqueous glucose D: aqueous calcium chloride E: aqueous nickel sulfate Which of these solutions are electrolyte solutions? a. A and E, only b. C, D and E, only c. A and D, only d. A, D and E, only e. B, D and E, only Section 5.2 7. Given the following set of solutions A: aqueous acetone B: aqueous silver nitrate C: aqueous ethylene glycol D: aqueous calcium chloride E: aqueous ammonium bromide Which of these solutions are electrolyte solutions? a. A and E, only b. C, D and E, only c. A and D, only e. B, D and E, only Section 5.2 8. Which statement below is correctly worded and states a fact? a. Ionic acids are strong electrolytes and ionize completely when dissolved in water. b. Ionic bases are weak electrolytes and ionize completely when dissolved in water. c. Ionic bases are strong electrolytes and ionize completely when dissolved in water. d. Ionic salts are strong electrolytes and dissociate completely when dissolved in water. e. Ionic salts are weak electrolytes and ionize partially when dissolved in water. 84 Section 5.2 9. Which one of the following compounds produces 4 ions per formula unit by dissociation when dis-solved in water? a. (NH4)2SO4 b. Hg2Cl2 c. Ca(NO3)2 d. Li3PO4 e. (NH4)4Fe(CN)6 Section 5.2 10. Which one of the following compounds produces 4 ions per formula unit by dissociation when dis-solved in water? a. K2C2O4 b. Al(NO3)3 c. Hg2(NO3)2 d. NaBrO3 e. Na2S2O3 Section 5.2 11. Which one of the following compounds produces 3 ions per formula unit by dissociation when dis-solved in water? a. sodium nitrate b. nickel sulfate c. calcium perchlorate d. aluminum sulfate e. ammonium bromate Section 5.2 12. Which one of the following compounds produces 3 ions per formula unit by dissociation when dis-solved in water? a. Hg2SO4 b. NaClO2 c. LiClO4 d. KClO e. (NH4)2SO4 85 Section 5.2 13. How many ions are produced in solution by dissociation of 1 formula unit of NiCl26H2O? a. 2 b. 3 c. 4 d. 6 e. 9 Section 5.2 14. How many ions are produced in solution by dissociation of 1 formula unit of Co(NO3)26H2O? a. 2 b. 3 c. 4 d. 6 e. 9 Section 5.4 21. Which one of the following compounds is insoluble in water? a. KNO3 b. Pb(NO3)2 c. Na2SO4 d. PbSO4 e. MgCl2 Section 5.4 22. Which one of the following compounds is insoluble in water? a. Na2CO3 b. NH4NO3 c. CaCO3 d. CaCl2 e. LiClO4 Section 5.5 29. Which one of the following would not be acidic? a. grapefruit juice b. household ammonia c. carbonated water d. vinegar e. lemon juice Section 5.5 30. According to the Arrhenius theory of Acids and Bases, acids are substances which a. exhibit a sour taste b. react with all metals to release hydrogen gas 86 c. react with all metals to release carbon dioxide gas d. release hydrogen ions when dissolved in water to form a solution e. turn litmus paper from blue to red Section 5.5 32. Which one of the following listed species is a molecular base? a. NaOH(s) b. NH3(g) c. C2H5OH(l) d. Li2O(s) e. NH4+(aq) Section 5.5 36. The chemical species present in all solutions which are moderately to strongly acidic, which is also responsible for the acidic property is a. H2O(aq) b. OH-(aq) c. H2O+(aq) d. H3O+(l) e. H3O+(aq) Section 5.5 38. Which one of the following substances will ionize when dissolved in water to form an aqueous solution? a. NaClO4(s) b. HNO3(l) c. C6H12O6(s) d. (NH4)2SO4(s) e. Ba(OH)2(s) Section 5.5 40. Which one of the following species is a weak electrolyte? a. HClO4(aq) b. HCl(aq) c. NaOH(aq) d. NH3(aq) e. LiOH(aq) Section 5.5 41. Which of the following properties is NOT a characteristic of solutions of strong acids? a. react with metals to yield CO2 gas b. exhibit a sour taste 87 c. turn litmus from blue to red d. neutralize bases e. react with carbonate salts to yield CO2 gas Section 5.7 50. Which one of the following acids is NOT a known strong acid? a. HBr(aq) b. HCl(aq) c. HClO3(aq) d. HF(aq) e. HI(aq) Section 5.7 51. Which one of the following bases is NOT a known strong base? a. Ca(OH)2(aq) b. Ba(OH)2(aq) c. KOH(aq) d. NaOH(aq) e. NH3(aq) Section 5.7 52. Which one of the following acids is NOT a known strong acid? a. HBr(aq) b. HC2H3O2(aq) c. HClO3(aq) d. HClO4(aq) e. HNO3(aq) Section 5.7 53. Which one of the following acids is a known strong acid? a. HBrO(aq) b. HClO2(aq) c. HF(aq) d. HI(aq) e. H3PO3(aq) Section 5.7 54. Which set below represents a group containing only weak electrolytes? a. HNO3(aq), H2SO4(aq), HCN(aq) b. KOH(aq), H3PO4(aq), NaClO4(aq) c. NH3(aq), HC2H3O2(aq), HCN(aq) d. NH4Cl(aq), HClO2(aq), HCN(aq) e. NaOH(aq), H2SO4(aq), HC2H3O2(aq) 88 Section 5.7 55. An acid-base neutralization is the reaction of a. H2(g) with O2(g) to form H2O(l) b. H2(aq) with OH-(aq) to form H2O(l) c. H+(aq) with O2(g) to form H2O(l) d. H+(aq) with OH-(aq) to form H2O(l) e. Na+(aq) with OH-(aq) to form NaOH(aq) Section 5.7 56. Which one of the following listed solutions is the least acidic (contains the lowest concentration of hydronium ions due to small degree of ionization)? a. 1.0 molar HCl(aq) b. 1.0 molar H2SO4(aq) c. 1.0 molar HClO4(aq) d. 1.0 molar HNO3(aq) e. 1.0 molar HCHO2(aq) Section 5.7 57. Which one of the following listed solutions is the least acidic (contains the lowest concentration of hydronium ions due to small degree of ionization)? a. 1.0 molar HCl(aq) b. 1.0 molar HClO3(aq) c. 1.0 molar HNO3(aq) d. 1.0 molar HNO2(aq) e. 1.0 molar HClO4(aq) Section 5.7 58. Which one of the following listed solutions is the least acidic (contains the lowest concentration of hydronium ions due to small degree of ionization)? a. 1.0 molar HF(aq) b. 1.0 molar HCl(aq) c. 1.0 molar HClO3(aq) d. 1.0 molar HBr(aq) e. 1.0 molar HI(aq) Section 5.7 59. Which one of the following listed solutions is the most acidic (contains the highest concentration of hydronium ions due to highest degree of ionization)? a. 1.0 molar HF(aq) b. 1.0 molar HC2H3O2(aq) c. 1.0 molar HCN(aq d. 1.0 molar HCl(aq) e. 1.0 molar HNO2(aq) 89 Section 5.7 60. Which one of the following listed solutions is the most acidic (contains the highest concentration of hydronium ions due to highest degree of ionization)? a. 1.0 molar HCN(aq) b. 1.0 molar HC2H3O2(aq) c. 1.0 molar HNO2(aq) d. 1.0 molar HF(aq) e. 1.0 molar HClO3(aq) Section 5.7 61. Which set below represents a group containing only weak acids? a. HC2H3O2(aq), HCN(aq), HNO2(aq) b. HC2H3O2(aq), HCN(aq), HNO3(aq) c. HC2H3O2(aq), HCl(aq), HNO2(aq) d. HClO(aq), HCN(aq), HBrO3(aq) e. HNO2(aq), HC2H3O2(aq), HI(aq) Section 5.7 62. A dynamic equilibrium is soon reached when acetic acid is dissolved in water. Which of the species shown below is present in largest amount in the solution? a. C2H3O2-(aq) b. H+(aq) c. HC2H3O2(aq) d. H3O+(aq) e. OH-(aq) Section 5.7 63. A dynamic equilibrium is soon reached when hydrogen fluoride is dissolved in water. Which of the species shown below is present in largest amount in the solution? a. H3O+(aq) b. HF(aq) c. H+(aq) d. F-(aq) e. OH-(aq) Section 5.7 64. A dynamic equilibrium is soon reached when hydrogen cyanide acid is dissolved in water. Which of the species shown below is present in largest amount in the solution? a. C2H3O2-(aq) b. H3O+(aq) c. OH-(aq) b. HCN(aq) e. H+(aq) Section 5.7 90 65. CH3NH2 is the formula for a molecular base. When this base is dissolved in water a small fraction of it ionizes. The formula for one of the products of this ionization is a. NH2+ b. CH3NHc. CH3NH2+ d. CH3NH3+ e. NH3+ Section 5.9 73. Which one of the following choices represents the net reaction which actually takes place in solution when HCl(aq) is added to CaCO3(s)? a. HCl(aq) + CaCO3(s) CaCl2(aq) + CO2(g) + H2O(l) b. H+(aq) + CaCO3(s) Ca2+(aq) + CO2(g) + H2O(l) c. HCl(aq) + CO32-(aq) Cl-(aq) + H2O(l) + CO2(g) d. Cl-(aq) + CaCO3(s) CaCl2(aq) + CO32-(aq) e. HCl(aq) + CaCO3(s) Ca2+(aq) + Cl2(g) + CO2(g) + H2O(l) Section 5.11 77. A 0.150 molar solution of sodium chloride in water should be prepared in a. a beaker b. an erlenmeyer flask c. a volumetric pipet d. a volumetric flask e. a florence (round bottom) flask Section 5.11 78. What is the molar concentration of a solution prepared by dissolving 0.100 moles of potassium ni-trate in enough water to prepare 400 mL of the solution? a. 2.50 x 10-4 molar b. 0.0400 molar c. 0.250 molar d. 4.00 molar e. 40.0 molar Section 5.11 79. 66.7 mL of 18.0 molar sulfuric acid solution was dissolved in enough water to make 500 mL of so-lution. The molarity of the diluted mixture is a. 2.40 molar b. 0.135 molar c. 36.0 molar d. 9.00 molar e. 0.00741 molar 91 Section 5.12 82. A solution is made by taking 54.62 grams of K2CrO4 in enough water to make 250.0 mL of solution. The molarity of the solution is therefore a. 0.0002813 molar b. 0.001125 molar c. 0.2813 molar d. 1.125 molar e. 1.409 molar Section 5.12 83. Sodium acetate, NaC2H3O2, has a formula weight of 82.034. What is the molar concentration of a solution prepared by dissolving 4.10 grams of sodium acetate in enough water to prepare 250 mL of the solution? a. 0.200 molar b. 1.025 molar c. 1.345 molar d. 5.00 molar e. 16.4 molar Section 5.12 85. A mixture was obtained by mixing the following: 50.0 mL of 0.200 molar NaCl, 25.0 mL of 0.300 molar BaCl2 and 125 mL of 0.150 molar NH4Cl. The total number of grams of the element, chlo-rine, in the mixture is a. 0.133 grams b. 0.428 grams c. 0.665 grams d. 0.1.47 grams e. 1.55 grams Section 5.12 86. How many mL of 3.25 molar (NH4)2SO4(aq) would be used, if it must contain 8.60 g of (NH4)2SO4 which is to be used up in a chemical reaction? a. 2.65 ml b. 20.0 ml c. 50.0 ml d. 265 ml e. 378 ml 92 93 Section 5.13 98. Lactic acid, (HC3H5O3), is a monoprotic acid that forms when milk becomes sour. In one laboratory exercise for students taking a food chemistry course, a 40.00 mL sample of an aqueous lactic acid solution required 26.50 mL of 0.140 molar NaOH(aq) to neutralize it during the course of a titration. From this data, what is the molar concentration of lactic acid in the solution? a. 0.0928 molar b. 0.148 molar c. 0.211 molar d. 0.757 molar e. 0.928 molar Section 5.13 99. Vinegar contains acetic acid (HC2H3O2), which is responsible for its acidity. In one analysis of a commercial (off the shelf) vinegar brand, a 15.00 mL sample was titrated with 0.450 molar NaOH(aq). It required 30.5 mL of this sodium hydroxide titrant to neutralize the acid in the vinegar sample. What is the molar concentration of acetic acid in the vinegar? a. 0.102 molar b. 0.221 molar c. 0.305 molar d. 0.458 molar e. 0.915 molar Section 5.13 100. Ascorbic acid (Vitamin C, H2C6H6O6), is a diprotic acid. In a laboratory exercise, a vitamin C tablet was analyzed by titration using 0.125 molar NaOH(aq). On the average, it required 29.5 mL of the base to neutralize the acid in the one tablet. How many mg of Vitamin C are there in one tablet? a. 100 mg b. 162 mg c. 273 mg d. 325 mg e. 649 mg Oxidation-Reduction Reactions Multiple Choice Section 6.1 1. Oxidation is defined as a. gain of a proton b. loss of a proton c. gain of an electron d. loss of an electron e. capture of an electron by a neutron Section 6.1 2. Which one of the statements below is true concerning an oxidation-reduction reaction? a. the reactant which is being reduced is the reducing reagent b. the reactant which is being oxidized is the reducing reagent c. the reactant which gains electrons is the reducing reagent d. the reactant which loses electrons is the oxidizing reagent e. none of the statements, ad, is true for an oxidation-reduction reaction Section 6.1 23. What is the change in oxidation number of each manganese atom in the process, KMnO4 MnSO4 a. +3 b. -3 c. -6 d. -5 e. +1 Section 6.4 99. Magnesium metal will displace hydrogen from non-oxidizing acids ___ ( ) Section 6.4 100. In terms of activity, the series, in increasing order for metals is found to be, Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs This means that cadmium will displace aluminum from aqueous solutions of aluminum sulfate ___ ( ) Section 6.5 102. When organic compounds which contain sulfur undergo complete combustion with oxygen, one of the products is hydrogen sulfide. ___ ( ) Section 6.5 103. When hydrocarbon compounds undergo combustion, the carbon is always converted into carbon dioxide. ___ ( ) 12 Section 6.5 104. Nitrogen-containing compounds present in coal and petroleum products are a major source of air pollutants which produce acid rain. ___ () Critical Thinking 107. In terms of activity, the series, in increasing order for metals is found to be, Au < Ag < Cu < Sn < Cd < Zn < Al < Mg < Na < Cs Which reaction below does not occur spontaneously upon mixing the reagents shown? a. Cd(s) + Al3+(aq) Cd2+(aq) + Al(s) b. Cd(s) + Cu2+(aq) Cd2+(aq) + Cu(s) c. Zn(s) + Cu2+(aq) Zn2+(aq) + Cu(s) d. Al(s) + Ag+(aq) Al3+(aq) + Ag(s) e. Cu(s) + Au3+(aq) Cu2+(aq) + Au(s) Section 6.6 108. A solution was made by taking 2.500g of KMnO4 and dissolving it in enough water to make 1.000 liter of solution. This solution was used to titrate H2C2O42H2O, a very pure substance. In acidic media, the reaction is MnO4-(aq) + H2C2O4(aq) + ___ CO2(g) + Mn2+(aq) + ____ How many mL of this solution are required to titrate a 0.480 g sample of H2C2O42H2O? ______ () Energy and Chemical Change: Breaking and Making Bonds Multiple Choice Section 7.1 2. Which one of the following is a unit of energy? a. pascal b. newton c. joule d. watt e. ampere Section 7.1 3. Chemical energy is a. the kinetic energy resulting from violent decomposition of energetic chemicals b. the heat energy associated with combustion reactions c. the electrical energy produced by fuel cells d. the potential energy which resides in chemical bonds e. the energy living plants receive from solar radiation Section 7.2 7. Which one of the following statements is true? a. Molecules in gases possess kinetic energy since they are in constant motion, while molecules in liquids and solids are not in constant motion and hence possess no kinetic energy. b. Molecules in gases and liquids possess kinetic energy since they are in constant motion, while molecules in solids are not in constant motion and hence possess no kinetic energy. c. Molecules in gases, liquids and solids possess kinetic energy since they are in constant motion. d. Polyatomic molecules possess kinetic energy in the liquid and gaseous states since the atoms can move about in the molecule even if the molecule cannot move. e. Since solids are rigid, their molecules do not possess kinetic energy unless the solid is melted. 139 Section 7.3 10. The internal energy of a chemical system is described by one of the equations below. Which one? a. Esystem = (Kinetic Energy)system + (Potential Energy)system b. Esystem = (Kinetic Energy)system - (Potential Energy)system c. Esystem = (Potential Energy)system - (Kinetic Energy)system d. Esystem = (Kinetic Energy)system e. Esystem = (Potential Energy)system Section 7.3 11. A 500.0 gram sample of aluminum is initially at 25.0 oC. It absorbs 32.60 kJ of heat from its sur-roundings. What is its final temperature, in oC? (specific heat = 0.9930 J g-1 oC-1 for aluminum) a. 40.4 oC b. 64.7 oC c. 65.7 oC d. 89.7 oC e. 90.7 oC Section 7.3 12. A 350.0 gram sample of copper is initially at 25.0 oC. It absorbs 12.50 kJ of heat from its surround-ings. What is its final temperature, to the nearest tenth of a degree? (specific heat = 0.3874 J g-1 oC-1 for copper) a. 38.8 oC b. 67.2 oC c. 92.2 oC d. 117.2 oC e. 156.7 oC Section 7.3 13. A calorimeter consists of metal parts with a heat capacity of 850.0 J oC-1 and 1100 grams of oil with a specific heat of 2.184 J g-1 oC-1. What is the heat capacity, in joules per degree, of the entire as-sembly? a. 1354 J oC-1 b. 1952 J oC-1 c. 2956 J oC-1 d. 3252 J oC-1 e. 4259 J oC-1 Section 7.3 15. A certain oil used in industrial transformers has a density of 1.086 g ml -1 and a specific heat of 1.826 J g-1 oC-1. Calculate the heat capacity of one gallon of this oil. (1 gallon = 3.785 liters) a. 0.4442 kJ oC-1 b. 0.5239 kJ oC-1 c. 2.251 kJ oC-1 140 d. 6.364 kJ oC-1 e. 7.506 kJ oC-1 Section 7.3 17. A calorimeter consists of metal parts with a heat capacity of 950.0 J oC-1 and 850 grams of oil with a specific heat of 2.418 J g -1 oC-1. Calculate the amount of heat energy required, in kJ, to raise its temperature from 25.00 oC to 31.60 oC. a. 4.91 kJ b. 11.9 kJ c. 19.8 kJ d. 20.8 kJ e. 28.7 kJ Section 7.3 20. A coffee cup calorimeter contains 525.0 grams of water at 25.0 oC. To it are added: 350.0 grams of water at 48.3 oC 480.0 grams of water at 63.8 oC Neglect the heat absorbed by the styrofoam, and calculate the final temperature. The specific heat of water is 4.184 J g-1 oC-1. a. 39.6 oC b. 45.7 oC c. 44.8 oC d. 66.7 oC e. 92.4 oC Section 7.3 21. A calorimeter consists of metal parts with a heat capacity of 850.0 J oC-1 and 1050 grams of oil with a specific heat of 2.148 J g-1 oC-1. Both are at 24.50 oC. A 500 g copper slug, at 220.0 oC is added. What is the final temp? Specific heat of copper = 0.3874 J g-1 oC-1. a. 33.4 oC b. 36.0 oC c. 36.8 oC d. 89.7 oC e. 120.5 oC Section 7.3 22. A calorimeter has metal parts (heat capacity of 850.0 J oC-1) and 1100 grams of oil (specific heat = 2.184 J g-1 oC-1), both at 24.50 oC. Adding a 460 g slug, at 240.0 oC, caused the temperature to rise to 32.5 oC. Find the specific heat of the metal! a. 0.236 J g-1 oC-1 b. 0.273 J g-1 oC-1 c. 0.309 J g-1 oC-1 d. 0.357 J g-1 oC-1 e. 2.28 J g-1 oC-1 Section 7.3 141 24. When pure sodium hydroxide is dissolved in water, heat is evolved. In a laboratory experiment to measure the molar heat of solution of sodium hydroxide, the following procedure was followed. To a calorimeter containing 300 g of water at 20.00 oC, 10.65 g of NaOH, also at 20.00 oC was added. The temperature change, which was monitored by a digital probe with negligible heat capacity, stopped when it reached a temperature of 28.50 oC. If the specific heat of the mixture is 4.184 J g -1 oC-1, and the small heat capacity of the calorimeter is ignored, what is the heat evolved, per mole of sodium hydroxide? a. -37.4 kJ b. -41.5 kJ c. -45.5 kJ d. -90.5 kJ e. -153 kJ Section 7.3 25. When pure sulfuric acid is dissolved in water, heat is evolved. In a laboratory experiment to measure the molar heat of solution of sulfuric acid, the following procedure was followed. To a calorimeter containing 300 g of water at 20.00 oC, 10.65 g of H2SO4, also at 20.00 oC was added. The temperature change, which was monitored by a digital probe with negligible heat capacity, ceased when it reached a temperature of 26.55 oC. If the specific heat of the mixture is 4.184 J g-1 oC-1, and the small heat capacity of the calorimeter is ignored, what is the heat evolved, per mole of sulfuric acid? a. -27.4 kJ b. -72.8 kJ c. -78.4 kJ d. -84.6 kJ e. -292 kJ Section 7.4 26. An exothermic chemical reaction has just occurred in an insulated isolated system. Which statement below is true? a. Heat was taken in from the surroundings by the system. b. Heat was given off to the surroundings by the system. c. The potential energy of the system increased. d. The potential energy of the system decreased. e. The total energy of the system increased. Section 7.4 27. An endothermic chemical reaction has just occurred in an insulated isolated system. Which statement below is true? a. Heat was taken in from the surroundings by the system. b. Heat was given off to the surroundings by the system. c. The potential energy of the system increased. d. The potential energy of the system decreased. e. The total energy of the system increased. 142 Section 7.4 28. During an exothermic chemical reaction, a. a system becomes warmer, and the chemical substances undergo an increase in potential energy b. a system becomes warmer, and the chemical substances undergo a decrease in potential energy c. a system becomes cooler, and the chemical substances undergo an increase in potential energy d. a system becomes cooler, and the chemical substances undergo a decrease in potential energy e. a system becomes warmer, and additional heat is gained from the surroundings Section 7.4 29. During an endothermic chemical reaction, a. a system becomes warmer, and the chemical substances undergo an increase in potential energy b. a system becomes warmer, and the chemical substances undergo a decrease in potential energy c. a system becomes cooler, and the chemical substances undergo an increase in potential energy d. a system becomes cooler, and the chemical substances undergo a decrease in potential energy e. a system becomes warmer, and additional heat is gained from the surroundings Section 7.5 31. For a chemical reaction taking place at constant pressure, which one of the following is true? a. Hsystem = (Kinetic Energy)system + (Potential Energy)system b. Hsystem = (Kinetic Energy)system - (Potential Energy)system c. Hsystem = Esystem - qp d. Hsystem = Esystem + PVsystem e. Hsystem = Esystem + qp Section 7.5 32. An endothermic reaction is one in which there is a. a positive value for the work (w > 0 joules) b. a negative value for the work (w < 0 joules) c. a negative value for H (H < 0 joules) d. a positive value for H (H > 0 joules) e. a negative value for E (E > 0 joules) 143 Section 7.5 35. A chemical reaction took place in a 6 liter cylindrical enclosure fitted with a piston (like the cylinder in an internal combustion engine of the piston driven type). Over the time required for the reaction to be complete, the system underwent a volume change from 0.400 liters to 3.20 liters. Which statement below is true beyond doubt or qualification? a. Work was performed on the system. b. Work was performed by the system. c. The internal energy of the system increased. d. The internal energy of the system decreased. e. The internal energy of the system remained unchanged. Section 7.5 36. A chemical reaction took place in a 5 liter cylindrical enclosure fitted with a piston (like the cylinder in an internal combustion engine of the piston driven type). Over the time required for the reaction to be complete, the system underwent a volume change from 1.40 liters to 3.70 liters. Which statement below is true beyond doubt or qualification? a. The enthalpy of the system remained unchanged. b. The enthalpy of the system decreased. c. The enthalpy of the system increased. d. Work was performed by the system. e. Work was performed on the system. Section 7.5 37. For a change in a system taking place at constant pressure, which statement below is true? a. H = E b. H = qp - P V c. H = E - qp d. H = qp e. E = qp Section 7.5 38. A closed, uninsulated system fitted with a movable piston so no matter is exchanged with the sur-roundings was assembled. Introduction of 430 J of heat caused the system to expand, doing 238 J of work in the process against a constant pressure of 101 kPa (kilopascals). What is the value of E for this process? a. (430 + 238) joules b. (430 - 238) joules c. (238 - 430) joules d. 430 joules e. (-238 - 430) joules Section 7.5 42. The values associated with the term, "standard reference conditions", in a thermochemical situation are 144 a. temperature: 0.00 K; pressure: 1.000 standard atmosphere b. temperature: 0.00 oC; pressure: 1.000 standard atmosphere c. temperature: 273.15 K; pressure: 1.000 Pascal d. temperature: 298.15 K; pressure: 1.000 standard atmosphere e. temperature: 298.15 K; pressure: 1.000 Pascal Section 7.8 55. The standard enthalpy of combustion for naphthalene, C10H8(s), is -5156.8 kJ mol-1. Using this data and the standard enthalpies of formation, : H2O(l) = -285.9 kJ mol-1; CO2(g) = -393.5 kJ mol-1, calculate the standard enthalpy of formation of C10H8(s), in kJ mol-1. ofH a. +78.2 kJ b. +935.9 kJ c. -1065.4 kJ d. +3619.7 kJ e. -10235.4 kJ Section 7.8 56. Complete combustion of hydrocarbons, or compounds with C,H, and O as the only elements, gives CO2 and H2O as the only products. If carried out under standard conditions, the CO2 is a gas while the H2O is a liquid. Given these standard enthalpies of combustion: C2H4(g) = -1411.08 kJ mol-1 C2H2(g) = -1299.65 kJ mol-1 H2(g) = -285.90 kJ mol-1 C(s) = -393.50 kJ mol-1 Calculate the standard enthalpy of reaction for the process, C2H2(g) + H2(g) C2H4(g) a. -174.47 kJ b. +397.33 kJ c. -961.47 kJ d. -2424.83 kJ e. -2996.63 kJ 145 The Quantum Mechanical Atom Multiple Choice Section 8.1 1. The frequency of an electromagnetic wave is a. the number of complete oscillations or cycles over a distance of one meter b. the number of complete oscillations or cycles in a one second time interval c. the distance between successive maxima in the wave in one complete cycle d. the number of complete oscillations or cycles over a distance of one centimeter e. the distance between successive nodes in the wave Section 8.1 2. The wavelength of an electromagnetic wave is a. the number of complete oscillations or cycles over a distance of one meter b. the number of complete oscillations or cycles in a one second time interval c. the distance between successive maxima in the wave d. the number of complete oscillations or cycles over a distance of one centimeter e. the distance between a minimum and the nearest maximum in the oscillation Section 8.1 9. A police radar unit is operating on a frequency of 9.527 Gigahertz. What is the wavelength of the radiation being employed? a. 314.7 nm b. 314.7 m c. 3.147 cm d. 314.7 cm e. 31.78 m 160 161 Section 8.1 15. Which one of the following types of radiation has the shortest wavelength? a. FM radio waves b. infrared radiation c. microwave radiation d. ultraviolet rays e. x-rays Section 8.1 16. Which one of the following types of radiation has the shortest wavelength? a. gamma rays b. infrared radiation c. microwave radiation d. ultraviolet rays e. visible light rays Section 8.1 18. Which one of the following types of radiation has the longest wavelength? a. gamma rays b. green colored visible light rays c. red colored visible light rays d. ultraviolet rays e. x-rays Section 8.1 19. Which one of the following types of radiation has the longest wavelength? a. gamma rays b. infrared radiation c. microwave radiation d. ultraviolet rays e. red colored visible light rays Chemical Bonding: General Concepts Multiple Choice Section 9.3 16. The atoms in the nitrogen molecule, N2, are held together by a. a single covalent bond b. a double covalent bond c. a triple covalent bond d. an ionic bond e. a magnetic dipole bond Section 9.3 17. The atoms in the oxygen molecule, O2, are held together by a. a single covalent bond b. a double covalent bond c. a triple covalent bond d. an ionic bond e. a magnetic dipole bond Section 9.3 18. The atoms in the hydrogen fluoride molecule are held together by a. a single covalent bond b. a double covalent bond c. a triple covalent bond d. an ionic bond e. a magnetic dipole bond Section 9.4 27. The structural formula for a certain alcohol can be written in condensed form as CH2CHCH2OH How many bonds should there be in this molecule? a. 8 b. 9 c. 10 d. 11 e. 12 Section 9.4 28. The structural formula for a certain alcohol can be written in condensed form as CH2CHCH2CH2OH How many bonds should there be in this molecule? a. 13 b. 14 187 188 c. 15 d. 16 e. 17 Section 9.5 39. Which one of the following bonds is the most polar one of the set? a. HBr b. HCl c. HF d. HI e. HN Section 9.5 40. Which one of the following bonds is the most polar one of the set? a. HC b. HCl c. HP d. HS e. HSe Section 9.5 41. Which one of the following bonds is the most polar one of the set? a. HC b. HN c. HP d. HO e. HSe Chemical Bonding and Molecular Structure Multiple Choice Section 10.3 33. Based on observed periodic trends, arrange the following species, HBr, HCl, HF, HI, in order of increasing dipole moment. a. HF < HCl < HBr < HI b. HBr < HCl < HF < HI c. HI < HF < HCl < HBr d. HI < HBr < HCl < HF e. HCl < HBr < HI < HF Section 10.3 34. Which of the following molecules CO2, CS2, NO2, COS is/are polar? a. NO2 only b. CS2, NO2, and COS c. CO2 only d. COS and NO2 e. COS only Section 10.3 36. Which one of the molecules below is a polar molecule? a. Br2 b. BF3 c. CO2 d. CS2 e. IBr Section 10.3 37. Which one of the molecules below is not polar, due to symmetric arrangement of electron domains? a. SO3 b. SO2 c. CO d. NH3 e. CH2Cl2 Section 10.3 38. Which one of the following is a polar molecule? a. XeF2 b. BrF5 c. XeF4 d. CCl4 e. PBr5 211 Chapter 11 Properties of Gases Multiple Choice Section 11.2 6. A properly designed Torricelli barometer (the simplest type of barometer) should be at least a. 50 cm tall b. 80 cm tall c. 2.50 meters tall d. 100 in tall e. 76 mm tall Section 11.2 9. The barometric pressure in a cavern was measured using a mercury barometer. A value of 74.2 cm of Hg was obtained. How many atmospheres is this? a. 5.64 atm b. 9.76 atm c. 1.024 atm d. 0.976 atm e. 56.4 atm Section 11.3 10. A real gas behaves most nearly like an ideal gas under condition of a. low temperature and high pressure b. low temperature and low pressure c. high temperature and low pressure d. high temperature and high pressure e. actually it will behave like an ideal gas regardless of the temperature or the pressure as long as it remains in the gaseous state Section 11.3 39. What volume would 11.2 g of a gaseous compound occupy at STP if the molecular weight of the compound is 56.0 g/mole and the substance behaves as an ideal gas? a. 4.48 liters b. 5.60 liters c. 11.2 liters d. 44.8 liters e. 110 liters 238 Section 11.4 44. A gas sample containing 0.3525 moles of a compound is trapped in a 2.641 liter vessel on a manifold at a temperature of 28.4 oC. What is the pressure in the vessel, in torr, if the gas behaves as an ideal gas? a. 334.6 torr b. 2007 torr c. 2510 torr d. 2513 torr e. 2694 torr Section 11.4 51. A student doing a laboratory study on determination of molecular mass of gases obtained the fol-lowing data for one of his unknowns: 6.155 grams of the gaseous substance occupied a volume of 1,484 ml when the temperature was held at 27.3 oC and the pressure in the measurement system was recorded as 747.2 torr. Calculate the molecular mass of the substance, assuming ideal gas behavior. a. 13.87 g mol -1 b. 30.40 g mol -1 c. 104.0 g mol -1 d. 106.7 g mol -1 e. 110.0 g mol -1 Section 11.5 59. What is the mole fraction of methane in a gaseous mixture that consists of 8.00 g of methane and 12.00 g of ethane, C2H6, in a 3.50 liter container maintained at 35.20oC? a. 0.400 b. 0.434 c. 0.555 d. 0.800 e. 1.50 Section 11.5 60. What is the mole fraction of hydrogen in a gaseous mixture that consists of 8.00 g of hydrogen and 12.00 g of neon in a 3.50 liter container maintained at 35.20oC? a. 0.150 b. 0.400 c. 0.660 d. 0.870 e. 0.930 Section 11.8 84. According to the kinetic theory of gases, the average kinetic energy of the gas particles in a gas sample is directly proportional to the 239 240 a. pressure b. volume c. temperature d. molar mass e. number of moles of gas Section 11.8 85. If container "A" is occupied by 1.00 mole of oxygen gas while container "B" is occupied by 20.0 grams of nitrogen gas and both containers are maintained at 0.00 oC and 650 torr then, a. container "B" must be larger than container "A" b. the average speed of the molecules in container "A" is greater than that of the molecules in container "B" c. container "A" must have a volume of 22.4 L d. the average kinetic energy of the molecules in "A" is equal to the average kinetic energy of the molecules in "B" e. the number of atoms in container "B" is greater than the number of atoms in container "A" Intermolecular Attractions and the Properties of Liquids and Solids Multiple Choice Section 12.2 1. The term, London forces, is a synonym for a. ion-ion forces b. permanent dipole-permanent dipole interactions c. hydrogen bonding d. instantaneous dipole-instantaneous dipole interactions e. instantaneous dipole-induced dipole interactions Section 12.2 2. Which one of the following molecules is most polarizable, and subject to significant instantaneous dipole-induced dipole forces? a. H3CBr b. H3CCl c. H3CF d. H3CH e. H3CI Section 12.2 3. For a series of small molecules of comparable molecular weight, which one of the following choices lists the intermolecular forces in the correct increasing order? a. hydrogen bonds < dipole-dipole forces < London forces b. dipole-dipole forces < hydrogen bonds < London forces c. London forces < hydrogen bonds < dipole-dipole forces d. hydrogen bonds < London forces < dipole-dipole forces e. London forces < dipole-dipole forces < hydrogen bonds Section 12.2 4. What one of the following covalent compounds will not exhibit hydrogen bonding in the liquid state? a. CH3u CH2u Br b. CH3u CH2u NH2 c. CH3u CH2u CH2u OH d. CH3 NH CH e. NH2 O H 3 268 Section 12.2 5. Which one of the following covalent compounds will exhibit hydrogen bonding in the liquid state? a. CH2F2 b. Cl2NH c. H2PCl d. HBr e. NCl3 Section 12.2 6. Which one of the following covalent compounds will exhibit hydrogen bonding in the liquid state? a. CCl2F2 b. H2PCl c. HCl d. NH2OH e. NF3 Section 12.2 7. Which compound is expected to have the strongest intermolecular forces? a. CH3u CH2u H b. CH3u CH2u Ou H c. CH3u CH2u PH2 d. CH3u CH2u Su H e. CH3u CH2u Seu H Section 12.2 8. Which compound is expected to have the weakest intermolecular forces? a. CH3u CH2u H b. CH3u CH2u Ou H c. CH3u CH2u PH2 d. CH3u CH2u Su H e. CH3u CH2u Seu H Section 12.2 9. It is now generally thought that the strongest intermolecular forces between molecules of HCl are a. covalent bonds b. dipole-dipole interactions c. ionic bonds d. hydrogen bonds e. London forces 269 Section 12.2 11. At 1.0 atm pressure, ice (solid H2O) floats in water instead of sinking. The reason for this is a. when water freezes, it expands instead of contracting b. the fusion process is endothermic, therefore the solid will float c. the triple point has a lower temperature than the freezing point for water d. the critical temperature has a higher temperature than the normal boiling point e. the triple point corresponds to a pressure below 1 standard atmosphere Section 12.3 12. The property that measures or describes the magnitude of resistance to flow in a liquid is called a. London forces b. malleability c. surface tension d. vapor pressure e. viscosity Section 12.3 13. Which one of the following is not a property or phenomenon associated with the liquid state? a. fluidity b. meniscus c. sublimation d. surface tension e. viscosity Section 12.3 14. Which one of the following is not a property or phenomenon associated with the liquid state? a. fluidity b. meniscus c. surface tension d. malleability e. viscosity Section 12.3 15. The ability of capillary tubing to draw liquids up against the action of gravity is an example of a. fluidity b. meiosis c. wetting and surface tension d. osmosis e. viscosity Section 12.4 16. When a liquid undergoes a phase change to a gas, the process is called 270 a. condensation b. deposition c. fusion d. sublimation e. evaporation Section 12.4 17. A liquid which is at room temperature is in equilibrium with its vapor, because there is a cover on the container. If the cover is removed, what is the immediate result? a. the average kinetic energy increases b. the evaporation rate decreases c. the evaporation rate increases d. the re-condensation rate decreases e. the re-condensation rate increases Section 12.5 18. Which one of the following listed compounds should have the lowest vapor pressure at a given tem-perature at which all these substances are in the liquid state? a. CH3u CH2u F b. CH3u CH2u CH3 c. CH3u CH2u CH2u CH3 d. CH3u CH2u Ou H e. CH3u Ou CH3 Section 12.5 19. Which one of the following listed compounds should have the lowest vapor pressure at a given tem-perature at which all these substances are in the liquid state? a. CCl3u Br b. CCl3u Cl c. CCl3u F d. CCl3u H e. CCl3u I Section 12.5 20. Which one of the following listed compounds should have the highest vapor pressure at a given temperature at which all these substances are in the liquid state? a. CH3u CH2u H b. CH3u Ou CH3 c. CH3u CH2u CH2u CH3 d. CH3u CH2u CH3 e. CH3u CH2u Su H Section 12.5 271 21. Which one of the following listed compounds should have the highest vapor pressure at a given temperature at which all these substances are in the liquid state? a. CCl3u Br b. CCl3u Cl c. CBr3u F d. CCl3u F e. CCl3u I Section 12.5 22. Which one of the following listed compounds should have the highest vapor pressure at a given temperature? a. CH3u Hgu CH3 b. CH3u Ou CH3 c. CH3u Su CH3 d. CH3u Seu CH3 e. CH3u Teu CH3 Section 12.6 23. The vapor pressure of a liquid increases with increasing temperature. The temperature at which this vapor pressure is equal to the prevailing outside atmospheric pressure is a. the boiling point b. the flash point c. the vaporization point d. 100 oC e. the normal boiling point Section 12.6 24. The vapor pressure of a liquid increases with increasing temperature. The temperature at which this vapor pressure is equal to 760 torr or 101,325 Pa is a. the boiling point b. the flash point c. the vaporization point d. 100 oC e. the normal boiling point Section 12.6 25. Which one of the following listed compounds should have the lowest boiling point temperature? a. CH3u Br b. CH3u Cl c. CH3u F d. CH3u H e. CH3u I 272 Section 12.6 26. Which one of the following listed compounds should have the lowest boiling point temperature? a. CH3u Hgu CH3 b. CH3u Ou CH3 c. CH3u Su CH3 d. CH3u Seu CH3 e. CH3u Teu CH3 Section 12.6 27. Which one of the compounds listed below should have the highest boiling point temperature? a. CH3u Br b. CH3u Cl c. CH3u F d. CH3u H e. CH3u I Section 12.6 28. Which one of the compounds listed below should have the highest boiling point temperature? a. CH3u Hgu CH3 b. CH3u Ou CH3 c. CH3u Su CH3 d. CH3u Seu CH3 e. CH3u Teu CH3 Section 12.6 29. Which one of the following factors has an effect on the value of the normal boiling point of a liquid? a. atmospheric pressure b. rate of condensation c. rate of evaporation d. strength of the intermolecular forces e. the external temperature Section 12.7 30. Given the following substances and their normal boiling points, in oC: C: 43.8 oC D: 93.7 oC M: 56.7 oC T: 83.5 oC R: 63.6 oC Which set below correctly lists some of these substances in order of decreasing vapor pressure at 20 oC? a. C > R > D b. D > T > R c. R > M > D d. C > D > M e. D > R > M 273 Section 12.7 31. Given the following substances and their normal boiling points, in oC: C: 43.8 oC D: 93.7 oC M: 56.7 oC T: 83.5 oC R: 63.6 oC Which set below correctly lists some of these substances in order of increasing vapor pressure at 20 oC? a. C < R < D b. T < R < C c. R < T < D d. C < D < M e. D < M < R Section 12.7 32. Given the following substances and their normal boiling points, in oC: C: 43.8 oC D: 93.7 oC M: 56.7 oC T: 83.5 oC R: 63.6 oC Which set below correctly lists some of these liquids in order of decreasing intermolecular forces at 20 oC? a. C > R > D b. D > C > R c. R > T > D d. C > D > M e. D > R > M 43. Given the phase changes: condensation, deposition, freezing, fusion, sublimation, vaporization. Which (set) of these phase changes is (are) endothermic? a. deposition, condensation, and freezing only b. fusion only c. fusion and vaporization only d. fusion, deposition and sublimation only e. sublimation, fusion, and vaporization only Section 12.7 44. Supercooling is defined as a. the extremely rapid cooling of a vapor to form a liquid b. the use of extremely cold refrigerants to achieve smaller crystal size when liquids are frozen c. the extremely rapid cooling of a liquid to form a softer crystalline solid d. the cooling of a liquid to a temperature below its melting point without solidification e. the cooling of a substance to absolute zero 274 Section 12.9 48. The critical temperature of a substance is a. always higher than the triple point temperature b. the temperature below which it cannot exist in the liquid state c. the temperature which is always higher than the Kelvin point d. the temperature below which it cannot be liquefied by increasing the pressure e. the temperature below which it cannot be supercooled Section 12.9 50. The triple point of a substance is the temperature and pressure at which a. all three physical states cease to exist b. sublimation, fusion, and condensation are taking place simultaneously c. the solid will always float on the liquid for all substances d. the vapor pressure of the liquid is higher than the vapor pressure of the solid e. the vapor pressure of the solid is higher than the vapor pressure of the liquid Questions 51 through 54 refer to the phase diagram immediately below P a *d e* b c T Section 12.9 51. At the temperature and pressure of point d, which statement below is true? a. The substance will sublime. b. There will be an equilibrium between the solid phase and the gaseous phase. c. Vaporization and deposition will take place simultaneously. d. Condensation and evaporation will take place simultaneously. e. The substance will be a superfluid. 275 276 Section 12.9 52. At the temperature and pressure of point e, which statement below is true? a. The substance will sublime. b. There will be an equilibrium between the solid phase and the gaseous phase. c. Vaporization and deposition will take place simultaneously. d. Fusion and freezing will take place simultaneously. e. Fusion and vaporization will take place simultaneously. Section 12.9 55. Which one of the following cannot be liquefied by compression at temperature of 25.0 oC? a. C2H4, critical point data: 9.9 oC, 50.5 atm b. CH3Cl, critical point data: 144.0 oC, 66.0 atm c. C2H2, critical point data: 35.5 oC, 61.6 atm d. C2H6, critical point data: 32.2 oC, 48.2 atm e. SO2, critical point data: 158.0 oC, 78.0 atm 59. In terms of kinetic theory, why would the coffee purchased in a container at the fast food takeout shop remain hot much longer than the coffee you pour into your ceramic cup at _______ ________________________________________________________________________ _______ home? ________________________________________________________________________ Structures, Properties and Applications of Solids Multiple Choice Section 13.2 5. A technique used for determination of the structure of a crystalline substance and obtaining information from which the unit cell data can be obtained is a. magnetic resonance imaging (MRI) b. microwave spectroscopy c. infrared spectroscopy d. ultraviolet laser scattering e. x-ray diffraction Section 13.3 29. Which set of properties below is associated with ionic crystalline substances? a. broad range of melting points, soft to hard, conductors in liquid and solid states b. high melting point, brittle, non-conductor c. high melting point, hard, not brittle, non-conductor d. low melting point, soft, non-conductor e. low melting point, soft, conductor in liquid and solid states 32. Paradichlorobenzene is a white crystalline solid which is very soft, has a low melting point, and is a non-conductor of electricity. Which category of substance does it most likely fit under? a. ionic b. molecular c. metallic d. covalent (network) e. amorphous Section 13.3 34. Which one of the following types of substance shows poorly defined fusion point temperatures? a. ionic b. molecular c. metallic d. covalent (network) e. amorphous 287 Solutions Multiple Choice Section 14.1 1. Concerning the process of separation of a solid substance into its component units (molecules or ions) where the interparticle distances are large compared to the particle sizes, the process is a. exothermic and the potential energy increases b. exothermic and the potential energy decreases c. endothermic and the potential energy increases d. endothermic and the potential energy decreases e. endothermic and occurs with no change in potential energy Section 14.1 2. Concerning the solvation step of the solution process, the process is a. exothermic and the potential energy increases b. exothermic and the potential energy decreases c. endothermic and the potential energy increases d. endothermic and the potential energy decreases e. endothermic and occurs with no change in potential energy Section 14.2 3. Wax is a solid mixture of hydrocarbon compounds consisting of molecules with long chains of car-bon atoms. Which solvent below would you expect to be most capable of dissolving wax by loosening the molecules in the solid and separating them? a. CH3a C CH O b. CH3 O H c. CH3a C H O d. H O 2u CH CH2a O H 3 e. CH3u CH2u CH2u CH2u CH2u CH2u CH2u CH3 307 Section 14.2 4. Wax is a solid mixture of hydrocarbon compounds consisting of molecules with long chains of car-bon atoms. Which solvent below would you expect to be most capable of dissolving wax by loosening the molecules in the solid and separating them? a. H O H b. CH3 O H c. CF3 O H d. H O 2u CH CH2 O H e. CH3u CH2u CH2u CH2u CH2u CH2u CH2u CH3 Section 14.3 5. A solution in a beaker has some undissolved solute lying on the bottom of the beaker. If the rate of crystallization exceeds the rate of dissolution of the excess solute, the solution is described as a. dilute b. concentrated c. unsaturated d. saturated e. supersaturated Section 14.3 6. A solution in a beaker has some undissolved solute lying on the bottom of the beaker. If the rate of crystallization is equal the to rate of dissolution of the excess solute, the solution is described as a. dilute b. concentrated c. unsaturated d. saturated e. supersaturated Section 14.3 7. A solution in a beaker has some undissolved solute lying on the bottom of the beaker. If the rate of crystallization is exceeded by the rate of dissolution of the excess solute, the solution is described as a. dilute b. concentrated c. unsaturated d. saturated e. supersaturated 308 Section 14.3 8. A solution is sitting undisturbed on a side shelf in the laboratory. A small crystal of the same solute of which the solution is made was gently dropped into the quiet solution. Suddenly, a mass of crys-tals formed and settled to the bottom of the container. The solution is, or must have been a. dilute b. concentrated c. unsaturated d. saturated e. supersaturated Section 14.4 9. Which one of the following causes an increase in the solubility of a gas in a given solvent in the situation in which the gas does not react with the solvent to form a new substance? a. increasing the temperature of the solvent and simultaneously decreasing the partial pres-sure of the gas in the space above the solvent b. decreasing the temperature of the solvent and simultaneously increasing the partial pres-sure of the gas in the space above the solvent c. increasing the temperature of the solvent and simultaneously increasing the partial pres-sure of the gas in the space above the solvent d. decreasing the temperature of the solvent and simultaneously decreasing the partial pres-sure of the gas in the space above the solvent e. increasing the temperature of the solvent while maintaining the partial pressure of the gas in the space above the solvent at a set value Section 14.4 10. The solubility of O2 in water is approximately 0.00380 grams per liter of water when the temperature is 25.0 oC and the partial pressure of gaseous oxygen is 760 torr. What should the solubility of oxygen be if the oxygen pressure is readjusted to 1000 torr? a. 0.00289 g L-1 b. 0.00500 g L-1 c. 1.49 g L-1 d. 2.89 x 103 g L-1 e. 3.46 x 103 g L-1 Section 14.5 13. Which one of the following is a concentration unit whose value will be altered if the temperature of an aqueous solution is changed, even if the solution remains unsaturated over the entire temperature range of the investigation? a. mole fraction b. molarity c. molality d. mass fraction e. percent by weight 309 Section 14.5 14. A solution is made by mixing 138.2 grams of ethanol, C 2H6O, (46.069 g mol-1), 103.6 grams of wa-ter (18.015 g mol-1), and 80.11 grams of methanol, CH4O (32.042 g mol-1). What is the mole frac-tion of methanol in the mixture? a. 0.02504 b. 0.2222 c. 0.2493 d. 0.3333 e. 0.4490 Section 14.5 18. A solution of sodium hydroxide is prepared by mixing 2.00 g of LiOH with 10.0 g of water. The percent, by mass, of LiOH is a. 10.7 % b. 12.0 % c. 16.7 % d. 20.0 % e. 80.0 % Section 14.5 19. How many grams of NaC2H3O2 (M = 82.034 g mol-1) should be dissolved in 400.0 g of water to prepare a solution which is 11.28 % NaC2H3O2 by mass? a. 3.146 g b. 7.558 g c. 21.17 g d. 50.86 g e. 127.15 g Section 14.5 20. A glucose solution is prepared by dissolving 5.10 g of glucose, C6H12O6, in 110.5 g of water. What is the molality of the glucose solution? a. 0.283 m b. 0.000256 m c. 0.245 m d. 0.256 m e. 0.351 m Section 14.5 21. A glucose solution is prepared by dissolving 15.2 g of glucose, C6H12O6, in 250.0 g of water. A stu-dent wants to make a sucrose solution (C 12H22O11) with the same molality. How many grams of su-crose should she use with 150.0 g of water, if that's how much solution she needs to prepare? a. 4.80 g b. 13.3 g 310 c. 17.3 g d. 18.0 g e. 48.1 g Section 14.5 24. A water solution which contains magnesium chloride as the only solute measured 232 parts per mil-lion (ppm) chloride on an analytical instrument using a specific ion electrode as the sensor unit. When converted to moles per liter, what value would you get for the chloride ion concentration? a. 0.00327 molar b. 0.00654 molar c. 0.01309 molar d. 0.0327 molar e. 0.654 molar Section 14.5 25. A water solution is saturated with MgC2O4 (which is only very slightly soluble in water). When 10.0 liters of this solution were evaporated to dryness, 14.8 g of the dry, solid magnesium oxalate dihydrate (MgC2O42H2O) were recovered as the only residue. The magnesium content can be expressed in parts per million (ppm). What is the magnesium content of the solution? The density of the solution is 1.000 g mL-1 at this dilution. a. 2.42 ppm b. 24.2 ppm c. 320 ppm d. 242 ppm e. 3.20 x 103 ppm Section 14.5 26. A solution of ethylene glycol (C2H6O2) in water is 3.981 molar and has a density of 1.0296 g mL-1. Calculate the percent, by weight, of ethylene glycol in the solution. a. 3.867 % b. 4.099 % c. 15.14 % d. 24.00 % e. 25.45 % Section 14.5 27. A solution of sodium nitrate, NaNO3, in water is 5.181 molar and its density is 1.2680 g mL-1. Cal-culate the percent, by weight, of sodium nitrate in the solution. a. 7.939 % b. 17.21 % c. 24.47 % d. 29.56 % e. 34.73 % Section 14.5 311 28. An aqueous solution of orthophosphoric acid, H3PO4, has a measured density of 1.2089 g mL-1 and is 5.257 molal. How many moles of H3PO4 are there in exactly one liter of this solution? a. 0.4261 moles b. 4.194 moles c. 4.349 moles d. 5.152 moles e. 6.355 moles Section 14.5 29. An aqueous solution of ethanol, C2H5OH, is 19.00% ethanol by mass and has a density of 0.9700 g mL-1. Calculate the molality of the ethanol solution. a. 4.000 m b. 4.124 m c. 4.252 m d. 5.092 m e. 14.48 m Section 14.8 59. Which one of the following can be applied to calculation of osmotic pressure in solutions? a. de Broglie equation b. Tyndall factor c. Peters equation d. van der Waals equation e. van't Hoff equation Section 14.8 61. Which one of the following listed properties of a solution is not a colligative property? a. solubility, in grams of solute per 100 grams of solvent b. freezing point depression c. boiling point elevation d. osmotic pressure e. vapor pressure lowering Section 14.8 62. During osmosis: a. pure solvent diffuses through a membrane but solutes do not b. pure solutes diffuse through a membrane but solvent does not c. pure solvent moves in one direction through the membrane while the solution moves through the membrane in the other direction d. pure solvent moves in one direction through the membrane while the solute moves through the membrane in the other direction e. pure solute moves in one direction through the membrane while the solution moves through the membrane in the other direction 312 Section 14.8 63. A very dilute solution contains 116 mg of fructose (M = 180.16 g mol-1) in 1.000 liter of solution. It is placed in a semipermeable membrane bladder, which is then suspended by a support in some pure water. What osmotic pressure would develop across the membrane if the temperature is 26.0 oC? a. 3.36 torr b. 12.0 torr c. 151 torr d. 475 torr e. 1217 torr Section 14.8 64. An aqueous solution made by dissolving 168 mg of an unknown compound ( a nonelectrolyte) in enough water to make 500.0 mL of solution, registered an osmotic pressure of 5.22 torr when the temperature was 23.5 oC. What is the molecular weight of this unknown compound? a. 94.3 g mol-1 b. 124 g mol-1 c. 943 g mol-1 d. 1.19 x 103 g mol-1 e. 1.57 x 103 g mol-1 Section 14.9 73. A solution was made by mixing 24.40 g of NaCl, 19.77 g of MgCl 2, 38.22 g of Na2SO4 and 1.665 kg of water. It had a measured density of 1.042 g mL-1. What is the colligative molality (moles of particles per kilogram of solvent) of the solution? a. 0.5371 molal b. 1.360 molal c. 1.418 molal d. 1.452 molal e. 4.297 molal Section 14.9 79. Which one of the following aqueous solutions has the highest osmotic pressure? a. 0.100 molar Al(NO3)3 b. 0.150 molar Ba(NO3)2 c. 0.100 molar CaCl2 d. 0.150 molar NaCl e. 0.200 molar NH3 313 Section 14.9 80. A dilute aqueous solution of CaCl2 contains 0.159 grams of solute per liter of solution. It is fully dissociated. What is the osmotic pressure, in torr, at 20.0 oC? a. 1.79 torr b. 3.49 torr c. 26.2 torr d. 78.6 torr e. 2.65 x 103 torr Section 14.10 83. When a liquid is dispersed in another liquid, the resulting colloid is called a(n) a. aerosol b. emulsion c. foam d. gel e. sol Section 14.10 84. The earliest soaps manufactured contained the functional group CO O They tend to form soap scums because this functional group is related to the carbonate ion, which forms insoluble compounds with all the ground water ions below except a. iron(III) b. calcium c. sodium d. magnesium e. aluminum 314 Chemistry in Practice 2 85. The Tyndall effect is not observed in one of the system types below. Which one? a. aerosol b. emulsion c. solution d. gel e. sol Section 14.10 86. The functional group O SO O is found in certain a. natural soaps b. synthetic detergents c. liquid aerosols d. sols e. Tyndall emulsions Section 14.10 87. The agitating action of the washing machine and the detergent action of soap on a mixture of auto-mobile engine oil and water produces a(n) a. aerosol b. emulsion c. solution d. gel e. sol Section 14.10 88. A soap or detergent can be classified by structure as a. an uncharged non-polar molecule b. an uncharged polar molecule c. an ionic molecule d. a salt e. an uncharged hydrogen bonding molecule 315 316 Fill in the Blanks True and False Section 14.1 95. One driving force toward formation of homogeneous gas mixtures is the spontaneity of random mixing through random motion of small molecules. ___ Section 14.1 96. Liquids which are mutually miscible possess intermolecular forces of similar type and magnitude. ___ Section 14.9 98. Colligative properties are similar in that they all depend on the concentration of solute particles in the solution. ___ Section 14.10 99. All soaps or detergents which contain a hydrocarbon tail are synthetic in origin. ___ Section 14.10 100. A soap micelle contains a considerable number of soap units with the hydrophobic tail facing outwards. ___ Kinetics: The Study of Rates of Reaction Multiple Choice Section 15.3 1. Mononitrogen monoxide reacts with bromine gas at elevated temperatures according to the equation, 2 NO(g) + Br2(g) 2 NOBr(g) In a certain reaction mixture the rate of formation of NOBr(g) was found to be 4.50 x 10-4 mol L-1 s-1. What is the rate of consumption of Br2(g), also in mol L-1 s-1? a. 4.50 x 10-4 mol L-1 s-1 b. 2.25 x 10-4 mol L-1 s-1 c. 9.00 x 10-4 mol L-1 s-1 d. 2.12 x 10-4 mol L-1 s-1 e. 2.03 x 10-3 mol L-1 s-1 Section 15.3 3. In a particular study of the reaction described by the equation, 2 CH4O(g) + 3 O2(g) 2 CO2(g) + 4 H2O(g), the rate of consumption of O2(g) is 0.400 mol L-1 s-1. What is the rate of formation of H2O(g) in the study? a. 0.300 mol L-1 s-1 b. 0.400 mol L-1 s-1 c. 0.533 mol L-1 s-1 d. 0.800 mol L-1 s-1 e. 1.33 mol L-1 s-1 Section 15.3 6. The units in which the rate of a chemical reaction in solution is measured are (could be) a. L2 mol-1 s-1 b. mol L-1 s-1 c. s-2 d. mol s L-1 e. sec L-1 mol-1 Section 15.4 8. A reaction has the rate law, rate = k[A][B]2. Which one of the following will cause the greatest in-crease in the reaction rate? a. decreasing the temperature without changing the concentrations b. doubling the concentration of B c. quadrupling the concentration of A d. tripling the concentration of B e. doubling the concentration of A Section 15.4 334 9. The reaction, 2 NO(g) + O2(g) 2 NO2(g), was found to be first order in each of the two reac-tants and second order overall. The rate law should therefore be written as a. rate = k[NO]2 b. rate = k([NO][O2] c. rate = k[NO2]2[NO]-2[O2]- d. rate = k[NO]2[O2]2 e. rate = k([NO][O2])2 Section 15.4 10. A reaction has the rate law, rate = k[A][B]2. What is the overall order of the reaction? a. 2 b. 4 c. 1 d. 3 e. 0 Section 15.4 11. A reaction has the rate law, rate = k[A][B] 2. What is the order of the reaction with respect to B? a. 2 b. 4 c. 1 d. 3 e. 0 Section 15.4 12. For the reaction, 2 XO + O2 2 XO2, some data obtained from measurement of the initial rate of reaction at varying concentrations are given below. run # [XO] [O2] rate, mmol L-1 s-1 1 0.010 0.010 2.5 2 0.010 0.020 5.0 3 0.030 0.020 45.0 The rate law is therefore a. rate = k[XO]2 [O2] b. rate = k[XO][O2]2 c. rate = k[XO][O2] d. rate = k[XO]2 [O2]2 e. rate = k[XO]2/[O2]2 Section 15.4 14. For the reaction, A + 2B C + 2 D, some initial rate measurements were carried out run # [A] [B] rate, mol L-1 s-1 1 0.100 0.200 0.000360 2 0.200 0.200 0.000720 335 3 0.100 0.400 0.000720 a. the rate law is therefore: rate = k[A][B]2 b. the rate law is therefore: rate = k[B] c. the rate law is therefore: rate = k[A] d. the rate law is therefore: rate = k[A][B] e. the rate law is therefore: rate = k[A]2[B] Section 15.4 15. For the reaction, A + 2 B C + 2 D, some measurements of the initial rate of reaction at vary-ing concentration gave the following data. run # [A] [B] rate, mol L-1 s-1 1 0.100 0.200 0.000360 2 0.150 0.200 0.000540 3 0.150 0.250 0.001055 a. the rate law is therefore: rate = k[A]2[B] b. the rate law is therefore: rate = k[A][B]2 c. the rate law is therefore: rate = k[A]2[B]2 d. the rate law is therefore: rate = k[A][B] e. the rate law is therefore: rate = k[A][B]3 21. The data below was obtained in a study on how the rate of a reaction was affected by the concentra-tion of the reactants. run # [A] [B] [C] rate, mol L-1 hr-1 1 0.200 0.100 0.600 5.0 2 0.200 0.400 0.400 80.0 3 0.600 0.100 0.200 15.0 4 0.200 0.100 0.200 5.0 5 0.200 0.200 0.400 20.0 From this data a. the order of the reaction with respect to C cannot be determined b. the reaction is second order with respect to C c. the reaction is zero order with respect to C d. the reaction is first order with respect to C e. the order of the reaction with respect to C is minus one (Rate prop to 1/[C]) Section 15.5 27. In a first order reaction with only one reagent, the reaction was started with a concentration of reac-tant equal to 0.0800 molar. After exactly two hours, the concentration had fallen to 0.0400 molar. What is the molarity after exactly six hours? a. 0.0000 M b. 0.0100 M c. 0.0150 M d. 0.0200 M 336 e. 0.0300 M Section 15.5 28. The half-life of a chemical reaction was found to be independent of the quantity of material which the researcher employed. The reaction is therefore a. possibly first order b. definitely first order c. zero order d. possibly second order e. definitely second order Section 15.5 29. The decomposition of an aldehyde solution in carbon tetrachloride is a first order reaction with a rate constant of 1.20 x 10-3 min-1. If we start with [aldehyde] = 0.0500 molar, what will the concentration be 150 minutes later? a. 0.00900 M b. 0.0418 M c. 0.00926 M d. 0.00499 M e. 0.000333 M Section 15.5 30. The rate constant for a first order decomposition reaction is 0.0111 min-1. What is the half-life of the reaction? a. 111 min b. 62.4 min c. 5000 sec d. 31.25 min e. 27.1 min Section 15.5 31. Given a reaction, 2 A + B P, for which the observed rate law is rate = k[A]. Which one of the following is true? a. [A] = 1/kt b. ln[A] = k/t c. 1/[A] = kt d. the half-life is 0.693/k e. e[A] = -kt Section 15.5 32. In a first order reaction, what fraction of the material will remain after 4 half-lives? a. 1/16 b. 1/8 c. 1/9 337 d. 1/4 e. 1/3 Section 15.5 33. The initial concentration of a reactant in a first order reaction is 0.620 molar. What will be its con-centration after 3 half-lives? a. 0.0865 M b. 0.310 M c. 0.0775 M d. 0.103 M e. 0.207 M Section 15.5 37. A reaction is first order overall. For a given sample, if its initial rate is 0.0200 mol L-1 s-1 and 25.0 days later its rate dropped to 6.25 x 10-4 mol L-1 s-1, what is its half-life? a. 25.0 days b. 50.0 days c. 12.5 days d. 5.0 days e. 37.5 days Section 15.7 41. The activation energy for a reaction can be found by finding the slope of a plot of ln(k) vs T-1 and a. adding this slope to -R b. multiplying this slope by 2.303 c. dividing this slope by -R d. multiplying this slope by 2.303R e. multiplying this slope by -R Section 15.7 42. For a chemical reaction, the rate constant at 250.0 oC is 0.00383 s-1, and the activation energy is 22.40 kilojoules. Calculate the value of the rate constant at 335.0 oC. a. 0.00513 s-1 b. 0.00946 s-1 c. 0.00787 s-1 d. 0.0224 s-1 e. 0.000640 s-1 Section 15.7 43. For a chemical reaction, the rate constant at 42.0 oC is 0.00395 s-1, while the rate constant at 67.4 oC is 0.0133 s-1. Calculate the value of the energy of activation, in kilojoules. a. 42.65 b. 1.13 c. 0.421 338 d. 18.5 e. 0.617 Section 15.7 44. The rate constant for a certain chemical reaction is 0.00250 L mol-1 s-1 at 25.0 oC and 0.0125 L mol-1 s-1 at 50.0 oC. What is the activation energy for the reaction, expressed in kJ? a. 25.1 kJ b. 51.6 kJ c. 37.6 kJ d. 45.3 kJ e. 60.3 kJ Section 15.7 45. For a particular chemical reaction, the rate constant at 30.0 oC is 1.38 x 10-4 L mol-1 s1, while the value at 49.0 oC is 1.21 x 10-3 L mol-1 s-1. What is the activation energy for this reaction? a. 92.8 kJ b. 200 kJ c. 40.4 kJ d. 343 kJ e. 56.4 kJ 56. A variable which has no effect on the rate of a chemical reaction under any circumstances is a. energy of activation b. catalyst c. concentration of the reactants d. temperature e. standard enthalpy of reaction for the system Section 15.9 58. A catalyst alters the rate of a chemical reaction by a. providing an alternate pathway which has a different activation energy b. changing the products formed in the reaction c. changing the frequency of collisions between molecules d. always providing a surface on which molecules react e. changing the enthalpy of reaction for the reaction Section 15.9 59. Which statement below is true concerning a negative catalyst? a. It lowers the energy of activation of the rate determining step. b. It increases the enthalpy of reaction. c. It never undergoes a chemical change at any time during a chemical reaction. d. It blocks the path with the highest energy of activation for the rate determining step. e. It blocks the path with the lowest energy of activation for the rate determining step. 339 340 Section 15.9 60. When a positive catalyst is used in a reaction which of the statements below describes the situation which occurs? a. The forward reaction rate is increased while the reverse reaction rate is retarded. b. The enthalpy change for the reaction becomes more exothermic. c. It does not affect the final (equilibrium) amounts of reactants and products. d. The activation energy for the reverse reaction is increased. e. The activation energy for the forward reaction is not altered. Chemical Equilibrium - General Concepts Multiple Choice Section 16.1 1. A chemical system is considered to have reached equilibrium when a. the frequency of collisions between the reactant molecules is equal to the frequency of collisions between the product molecules b. the sum of the concentrations of each of the reactant species is equal to the sum of the concentrations of each of the product species c. the activation energy of the forward reaction is equal to the activation energy of the reverse reaction d. the rate of production of each of the product species is equal to the rate of consumption of each of the product species by the reverse reaction e. the rate of production of each of the product species is equal to the rate of consumption of each of the reactant species Section 16.1 2. A chemical system is considered to have reached equilibrium when a. the rate of consumption of each of the product species by the reverse reaction is equal to the rate of production of each of the reactant species by the reverse reaction b. the sum of the concentrations of each of the reactant species is equal to the sum of the concentrations of each of the product species c. the rate of production of each of the product species is equal to the rate of consumption of each of the product species by the reverse reaction d. the rate of production of each of the product species is equal to the rate of consumption of each of the reactant species by the reverse reaction e. the rate of production of each of the product species by the forward reaction is equal to the rate of production of each of the reactant species by the reverse reaction Section 16.2 3. All of the following statements about chemical equilibrium are true except: a. At equilibrium, the reactant and the product concentrations show no further change with time. b. A true chemical equilibrium can only be attained starting with reagents from the reactant side of the equation. c. At equilibrium, the forward reaction rate equals the reverse reaction rate. d. The same equilibrium state can be attained starting either from the reactant or product side of the equation. e. At equilibrium, the reactant and product concentrations are constant. 355 Section 16.2 5. In a study of the system, Cl2(g) + Br2(g) 2 BrCl(g), at 350 K, several different reaction mixes, described below, were prepared, placed in a 5.00 liter container, and allowed to attain equilibrium at 350 K. Despite having different starting compositions, as shown, four of the five mixtures had the identical composition at equilibrium. Which one of the systems attains a different equilibrium composition than the others? a. System 1: 0.100 moles of Cl2, 0.000 moles of Br2 and 0.600 moles of BrCl b. System 2: 0.250 moles of Cl2, 0.150 moles of Br2 and 0.300 moles of BrCl c. System 3: 0.400 moles of Cl2, 0.300 moles of Br2 and 0.000 moles of BrCl d. System 4: 0.300 moles of Cl2, 0.250 moles of Br2 and 0.250 moles of BrCl e. System 5: 0.350 moles of Cl2, 0.250 moles of Br2 and 0.100 moles of BrCl Section 16.2 6. In a study of the system, N2O4(g) 2 NO2(g), at 585 K, several different reaction mixes, de-scribed below, were prepared, placed in a 5.00 liter container, and allowed to attain equilibrium at 480 K. Despite having different starting compositions, as shown, four of the five mixtures had the identical composition at equilibrium. Which one of the systems attains a different equilibrium composition than the others? a. System 1: 0.400 moles of N2O4 and 0.800 moles of NO2 b. System 2: 0.300 moles of N2O4 and 1.000 moles of NO2 c. System 3: 0.800 moles of N2O4 and 0.000 moles of NO2 d. System 4: 0.600 moles of N2O4 and 0.400 moles of NO2 e. System 5: 0.400 moles of N2O4 and 0.700 moles of NO2 Section 16.3 8. Given the pair of reactions shown with the equilibrium constants, PCl3(g) + Cl2(g) PCl5(g) K1 2 NO(g) + Cl2(g) 2 NOCl(g) K2 What is the equilibrium constant for the reaction, PCl5(g + 2 NO(g) PCl3(g) + 2 NOCl(g) a. K1K2 b. K2/K1 c. K1/K2 d. (K1K2)-1 e. K2-K1 Section 16.3 356 11. Using this data, 2 NO(g) + Cl2(g) 2 NOCl(g) Kc = 3.20 x 10-3 2 NO2(g) 2 NO(g) + O2(g) Kc = 15.5 calculate a value for Kc for the reaction, NOCl(g) + O2(g) NO2(g) + Cl2(g) a. 2.06 x 10-4 b. 4.84 x 10-3 c. 0.223 d. 4.49 e. 20.2 18. The concentration of a pure solid or a pure liquid is left out of the expression for the equilibrium constant because a. solids and liquids drive the reaction in an undetermined fashion b. solids and liquids do not react c. their concentrations cannot be determined d. solids and liquids react too slowly e. their activity is constant and independent of the amount of solid or liquid present Section 16.7 19. The equilibrium constant, Kc, for the system, CaO(s) + CO2(g) CaCO3(s), is a. Kc = [CO2] b. Kc = [CaCO3]/([CaO] x [CO2]) c. Kc = 1/[CO2] d. Kc = [CaCO3]/[CaO] e. Kc = ([CaO] x [CO2])/[CaCO3] Section 16.8 20. Given the reaction, 2 NO(g) + O2(g) 2 NO2(g), for which the enthalpy of reaction is -118.9 kJ. Which one of the following will cause an increase in the equilibrium concentration of NO in a closed reaction chamber? a. adding some more O2(g) through an injection nozzle b. increasing the temperature of the system c. removing the NO2 from the system by absorbing it in a species specific zeolite d. increasing the pressure of the system while temperature is kept constant e. adding a catalyst Section 16.8 21. For a specific reaction, which of the following statements can be made about the equilibrium con-stant? a. it can change with temperature 357 b. it may be changed by addition of a catalyst c. it increases if the concentration of one of the products is increased d. it increases if the concentration of one of the products is decreased e. it always remains the same 358 359 Section 16.8 22. The reaction, 2 SO3(g) 2 SO2(g) + O2(g) is endothermic. Predict what will happen if the tem-perature is increased. a. Kc remains the same b. Kc decreases c. the pressure decreases d. more SO3(g) is produced e. Kc increases Section 16.9 45. A study of the system, H2(g) + I2(g) 2 HI(g), was carried out. Kc = 54.9 at 699.0 K for this reaction. A system was charged with 2.50 moles of HI in a 5.00 liter vessel as the only component initially. The system was brought up to 699.0 K and allowed to attain equilibrium. How many moles of H2 should there be in the container at that time? a. 0.337 moles b. 1.25 moles c. 0.297 moles d. 0.500 moles e. 0.266 moles Section 16.3 55. Write the expression for the equilibrium constant, Kc, for the reaction, N2H4(g) + 6 H2O2(g) 2 NO2(g) + 8 H2O(g) Section 16.4 56. Write the correct expression for the equilibrium constant for the reaction below CH4(g) + 2 NO2(g) CO2(g) + 2 H2O(g) + N2(g) 57. Write the expression for the equilibrium constant, Kp, for the reaction, N2(g) + O2(g) 2 NO(g) True and False 64. In a chemical reaction system which has reached equilibrium, the concentrations of the various spe-cies are constantly changing even though the total number of molecules is unchanging. ___ Section 16.1 65. In a chemical reaction system which has reached equilibrium the net concentration of each species is unchanging even though particular molecules continue to react throughout the system. ___ Acids and Bases: A Second Look Multiple Choice Section 17.1 1. The conjugate acid of HPO42- is a. H2PO4 b. H3PO4 c. PO43d. PO42e. H2PO4Section 17.1 2. The conjugate base of HPO42- is a. H2PO4 b. H3PO4 c. PO43d. PO42e. H2PO4Section 17.1 3. The conjugate base of H2SO4 is a. SO42b. H3O+ c. OHd. HSO4e. H2SO3 Section 17.1 5. The conjugate acid of NH3 is a. NH4 b. NH3+ c. H+ d. H3O+ e. NH4+ Section 17.1 7. Which one of the following species is amphiprotic? a. PO43-(aq) b. HCl(g) c. HSO4-(aq) d. Cl-(aq) e. CO32-(aq) 372 Section 17.1 8. Which one of the following species is amphiprotic? a. HNO3(aq) b. Cl-(g) c. CO32-(aq) d. HSO3-(aq) e. PO43-(aq) Section 17.1 9. Which one of the following species is amphiprotic? a. AsO43-(aq) b. HBr(aq) c. HF(aq) d. SO42-(aq) e. HCO3-(aq) Section 17.1 10. Which one of the species listed below does not have a conjugate base? a. H2O b. H3O+ c. NH2d. OHe. FSection 17.1 11. Which one of the species below has a conjugate base? a. Clb. SO42c. CNd. OHe. CO32Section 17.1 12. In the reaction, HClO3 + N2H4 ClO3- + N2H5+, which one of the sets below constitutes a conjugate (acid-base) pair? a. HClO3, N2H4 b. N2H4, ClO3c. HClO3, N2H5+ d. N2H4, N2H5+ e. ClO3-, N2H5+ Section 17.2 373 24. Which one of the five species shown below is the strongest oxyacid? a. O H b. O H O c. O X O H O d. O H H e. O H O X6 H H Section 17.2 25. Which one of the five species shown below is the strongest oxyacid? a. O H b. O X O H O c. O H OX O H OX O H OX O H H OX O H OX O H O 374 d. O H O XO O e. O H H Section 17.2 Section 17.2 32. Which one of the following four species is the most acidic substance? a. HClO b. HClO2 c. HClO3 d. HClO4 e. ClSection 17.2 37. Which one of the following four species is the least acidic substance? a. HBr b. HCl c. HF d. HI Section 17.2 38. Which one of the following four species is the most acidic substance? a. H2O b. H2S c. H2Se d. H2Te OXO H 375 Section 17.4 45. Which one of the following solutions should have the lowest pH? a. Al(NO3)3(aq) b. Ca(NO3)2(aq) c. KNO3(aq) d. Mg(NO3)2(aq) e. Zn(NO3)2(aq) Section 17.4 46. Which one of the following solutions should have the highest pH? a. Al(NO3)3(aq) b. Ga(NO3)3(aq) c. AgNO3(aq) d. Cu(NO3)2(aq) e. Zn(NO3)2(aq) Section 17.4 47. Which one of the following solutions should have the lowest pH? a. Zn(NO3)2(aq) b. Cd(NO3)2(aq) c. Ga(NO3)3 (aq) d. Hg(NO3)2(aq) e. Al(NO3)3(aq) Section 17.4 48. Which one of the following solutions should have the highest pH? a. Al(NO3)3(aq) b. Cd(NO3)2(aq) c. Ga(NO3)3 (aq) d. KNO3(aq) e. Zn(NO3)2(aq) Section 17.4 49. Five solutions were prepared by dissolving 0.00100 moles of each of the following in enough water to make 1.000 liters of solution. Which one of the solutions would you expect to be the most acidic? The one made with a. CO2 b. P4O6 c. P4O10 d. SO2 e. SO3 376 Section 17.4 50. Five solutions were prepared by dissolving 0.00100 moles of each of the following in enough water to make 1.000 liters of solution. Which one of the solutions would you expect to be the most acidic? The one made with a. Na2O b. BaO c. Ga2O3 d. Al2O3 e. P4O6 57. An aqueous solution at 25.0 oC has an H+ concentration of 4.0 x 10-2 molar. What is the OH- concentration in the same solution, in moles per liter? a. 4.0 x 10-2 b. 4.0 x 10-9 c. 4.0 x 10-12 d. 2.5 x 10-13 e. 25.0 Section 17.5 58. If the H+ ion concentration in an aqueous solution at 25.0 oC has a value of 0.100 molar, then the OH- concentration in moles per liter is a. 0.100 b. 1.00 x 10-7 c. 100 x 10-12 d. 1.00 x 10-13 e. 4.00 x 1012 Section 17.5 59. If the H+ ion concentration in an aqueous solution at 25.0 oC has a value of 0.100 molar, then the pOH of the solution is a. 1.00 b. 7.00 c. 12.00 d. 13.00 e. 11.40 Section 17.5 60. If the H+ ion concentration in an aqueous solution at 25.0 oC has a value of 0.100 molar, then the pH of the solution is a. -1.00 b. 0.100 c. 1.00 d. 6.90 e. 13.00 377 Section 17.5 61. If the OH- ion concentration in an aqueous solution at 25.0 oC is 6.6 x 10-4 M, then the H+ concen-tration in moles per liter in the same solution is a. 1.5 x 10-1 b. 1.5 x 10-4 c. 6.6 x 10-10 d. 1.5 x 10-11 e. 6.6 x 10-11 Section 17.5 62. If the OH- ion concentration in an aqueous solution at 25.0 oC is 3.4 x 10-3 M, then the H+ concen-tration in moles per liter in the same solution is a. 2.9 x 10-3 b. 2.9 x 10-12 c. 3.4 x 10-17 d. 5.8 x 10-9 e. 6.6 x 10-10 Section 17.5 63. If the H+ ion concentration in an aqueous solution at 25.0 oC is measured as 6.6 x 10-4 M, then the pH is a. 3.00 b. 3.18 c. 6.60 d. 9.55 e. 10.82 Section 17.5 64. If the OH- ion concentration in an aqueous solution at 25.0 oC is measured as 3.4 x 103 M, then the pH is a. 2.47 b. 7.22 c. 8.24 d. 11.53 e. 16.47 378 Section 17.5 65. A mixture is made using 50.0 ml of 0.20 M NaOH(aq) and 50.0 ml of water. At 25.0 oC, what is its pH? a. 1.00 b. 4.55 c. 7.00 d. 13.00 e. 13.30 Section 17.5 66. Calculate the pH of a mixture made by adding 50.0 ml of 0.20 M HCl(aq) to 150.0 ml of water if the temperature of the mixture is 25.0 oC. a. 0.70 b. 1.00 c. 1.18 d. 1.30 e. 13.00 Section 17.5 67. Calculate the pH of a 0.020 M solution of Ca(OH)2 whose temperature is 25.0 oC. a. 1.40 b. 0.040 c. 1.69 d. 12.60 e. 12.30 Fill in the Blanks Section 17.2 68. The strongest base that can exist in aqueous solution is _____. ( ) Section 17.2 69. The strongest acid that can exist in aqueous solution is _____. ( ) Section 17.2 70. What is the formula for the conjugate base of NH3(aq)? _____ (-) Section 17.2 71. What is the formula for the conjugate base of the OH-(aq) ion? _____ () True and False Section 17.1 82. The conjugate acid of HCl(aq) is H+(aq). ___ ( ) Section 17.1 379 83. The conjugate base of NH3 is NH4OH(aq). ___ () Section 17.1 84. The conjugate acid of Cl-(aq) is HCl(aq). ___ () Section 17.1 85. NH4Cl(aq) is one of the conjugate bases of Cl-(aq) ___ () Section 17.1 86. The H2PO4-(aq) ion is amphiprotic in water solution. ___ () Section 17.5 88. The ion product constant for water, Kw, varies with the temperature of the water. ___ () Critical Thinking Section 17.5 89. At 60 oC the value of Kw is 9.5 x 10-14. Considering this, what is the calculated value for the pOH of a 2.00 x 10-3 M HCl(aq) solution at this temperature? a. 2.70 b. 6.51 c. 10.32 d. 11.30 e. 13.02 Section 17.5 90. At 60 oC the value of Kw is 9.5 x 10-14. Considering this, what is the calculated value for the pH of a 5.00 x 10-2 M Ba(OH)2(aq) solution at this temperature? a. 1.00 b. 1.30 c. 12.02 d. 12.70 e. 13.00 Section 17.5 91. At 60 oC the value of Kw is 9.5 x 10-14. Considering this, what is the calculated value for the pOH of pure water this temperature? a. 6.02 b. 6.51 c. 7.00 d. 7.49 e. 9.50 Section 17.5 380 381 92. At 60 oC the value of Kw is 9.5 x 10-14. Considering this, what is the calculated value for the pH of a solution made by dissolving 1.00 g of sodium hydroxide in enough water to make 500 ml of solution at this temperature? _________ ( ) Equilibria in Solutions of Weak Acids and Bases Multiple Choice Section 18.1 1. The ionization constant, Ka, for macnic acid is 5.0 x 10-5. What is the pKa of this acid? a. 2.00 x 104 b. 4.30 c. 5.70 d. 1.75 x 10-1 e. 10.70 Section 18.1 2. The ionization constant, Ka, for lactic acid is 1.38 x 10-4. What is the pKa of this acid? a. 7.25 x 103 b. 2.591 c. 3.860 d. 5.380 e. 3.591 Section 18.1 3. The ionization constant, Ka, for benzoic acid is 6.28 x 10-5. What is the pKa of this acid? a. 1.592 x 104 b. 4.202 c. 4.452 d. 5.640 e. 9.800 Section 18.1 4. The ionization constant, Kb, for ammonia has a value of 1.76 x 10-5. What is the pKb of this base? a. +3.24 b. -4.75 c. +4.75 d. -9.25 e. +9.25 1 Section 18.1 5. Hydrazine is a chemical base, and the value of its constant, Kb, is 1.70 x 10-6. What is the value of pKb for this base? a. +4.30 b. +5.77 c. -5.77 d. +8.23 e. -8.23 Section 18.1 6. Butanoic acid, HC4H7O2, has a pKa value = 4.82. What is the value of the ionization constant for butanoic acid? a. 8.08 x 10-3 b. 1.51 x 10-5 c. 4.82 x 10-7 d. 6.61 x 10-10 e. 1.24 x 10-12 Section 18.1 7. Hypochlorous acid, HClO, has a pKa value = 7.52. What is the value of the ionization constant for hypochlorous acid? a. 5.42 x 10-4 b. 3.31 x 10-7 c. 7.52 x 10-7 d. 3.02 x 10-8 e. 1.84 x 10-11 Section 18.2 8. A 0.100 M solution of an acid, HA, has a pH = 2.00. What is the value of the ionization constant, Ka for this acid? a. 1.1 x 10-2 b. 1.1 x 10-3 c. 1.1 x 10-4 d. 1.0 x 10-3 e. 1.0 x 10-4 2 Section 18.2 9. A 0.500 M solution of an acid, HQ, has a pH = 1.301. What is the value of the ionization constant, Ka, for this acid? a. 5.00 x 10-2 b. 1.25 x 10-3 c. 5.56 x 10-3 d. 6.25 x 10-3 e. 7.14 x 10-3 Section 18.2 10. A 0.200 M solution of an acid, HBrun, has a pH = 1.00. What is the value of the ionization con-stant, Ka, for this acid? a. 0.200 b. 0.0400 c. 1.00 x 10-3 d. 1.00 e. 1.00 x 10-1 Section 18.2 11. A 0.300 M solution of an acid, HZ, has a pH = 1.301. What is the value of the ionization constant, Ka, for this acid? a. 1.67 x 10-1 b. 2.00 x 10-1 c. 1.00 x 10-2 d. 7.14 x 10-3 e. 8.33 x 10-3 Section 18.2 12. A 0.200 M solution of a weak base in water has a pH = 10.40. Calculate the value of Kb for this base. a. 1.0 x 10-5 b. 3.2 x 10-7 c. 2.2 x 10-5 d. 4.0 x 10-11 e. 5.0 x 10-5 3 Section 18.2 13. Formic acid, HCO2H, has an ionization constant with the value: Ka = 1.76 x 10-4. Calculate the value of pKb for the conjugate base of formic acid. a. +3.75 b. +5.35 c. +8.65 d. +10.25 e. +12.24 Section 18.2 14. Benzoic acid, HC7H5O2, has an ionization constant with the value: Ka = 6.4 x 10-5. Calculate the value of pKb for the conjugate base of benzoic acid. a. +4.19 b. +4.35 c. +9.65 d. +9.81 e. +13.46 Section 18.2 15. m-Toluic acid, HC8H7O2, has an ionization constant with the value: Ka = 1.23 x 10-4. Calculate the value of pKb for the conjugate base of m-toluic acid. a. +3.91 b. +5.00 c. +8.23 d. +9.00 e. +10.09 Section 18.2 16. The ionization constant, Ka, for benzoic acid, HC7H5O2, is 6.28 x 10-5. What is the pH of a 0.15 molar solution of this acid? a. 0.82 b. 2.52 c. 4.20 d. 5.03 e. 5.79 4 Section 18.2 17. The ionization constant, Ka, for acetic acid, HC2H3O2, is 1.76 x 10-5. What is the pH of a 0.0800 molar solution of this acid? a. 1.10 b. 2.01 c. 2.93 d. 4.75 e. 5.85 Section 18.2 18. What is the pH of a 1.00 molar solution of nitrous acid? The K a for nitrous acid is 7.1 x 10-4. a. 1.57 b. 1.58 c. 1.60 d. 2.67 e. 3.15 Section 18.2 19. The ionization constant, Ka, for dichloroacetic acid, HC2HO2Cl2 , is 5.0 x 10-2. What is the pH of a 0.15 molar solution of this acid? a. 1.06 b. 1.19 c. 1.30 d. 1.56 e. 1.82 Section 18.2 20. The ionization constant, Kb, for the weak base methylamine, CH3NH2, is 4.4 x 10-4. What is the pH of a 0.080 molar solution of this base? a. 2.23 b. 2.24 c. 5.87 d. 10.64 e. 11.76 Section 18.2 21. The ionization constant, Kb, for the weak base trimethylamine, (CH3)3N, is 7.4 x 10-5. What is the pH of a 0.040 molar solution of this base? a. 8.37 b. 9.87 c. 10.70 d. 11.23 e. 12.60 5 Section 18.3 22. The ionization constant, Ka, for HCN(aq) is 6.2 x 10-10. What is the pH of a 0.10 molar solution of sodium cyanide, which contains the cyanide ion? a. 5.10 b. 8.90 c. 9.21 d. 11.10 e. 11.30 Section 18.3 23. The ionization constant, Ka, for HOI(aq), hypoiodous acid, is 2.3 x 10-11. What is the pH of a 0.050 molar solution of sodium hypoiodite, which contains the hypoiodite ion? a. 5.97 b. 8.03 c. 10.64 d. 11.65 e. 12.70 Section 18.4 31. What is the pH of a 1.00 x 10-9 molar solution of HCl? a. 5.00 b. 6.00 c. 6.80 d. 7.00 e. 9.00 Section 18.5 34. A buffer solution is prepared by taking 0.400 moles of acetic acid (pKa = 4.76) and 0.250 moles of sodium acetate in sufficient water to make 1.400 liters of solution. Calculate the pH of this solution. a. 4.46 b. 4.56 c. 4.66 d. 4.86 e. 4.96 Section 18.5 35. A buffer solution is prepared by taking 0.250 moles of acetic acid (pKa = 4.76) and 0.400 moles of sodium acetate in sufficient water to make 1.800 liters of solution. Calculate the solution pH. a. 4.56 b. 4.66 c. 4.86 d. 4.96 6 e. 5.06 Section 18.5 36. A buffer solution is prepared by taking 0.400 moles of acetic acid (pKa = 4.76) and 0.250 moles of calcium acetate in sufficient water to make 1.400 liters of solution. Calculate the pH of this solution. a. 4.46 b. 4.56 c. 4.66 d. 4.86 e. 4.96 Section 18.5 37. A buffer solution is prepared by taking 0.250 moles of acetic acid (pKa = 4.76) and 0.400 moles of barium acetate in sufficient water to make 1.400 liters of solution. Calculate the pH of this solution. a. 4.25 b. 4.45 c. 5.00 d. 5.27 e. 5.35 Section 18.5 38. The pKa of acetic acid, HC2H3O2, is 4.76. A buffer solution was made using an unspecified amount of acetic acid and 0.30 moles of NaC2H3O2 in enough water to make 2.00 liters of solution. Its pH was measured as 4.40 on a meter. How many moles of HC2H3O2 were used? a. 0.13 mol b. 0.18 mol c. 0.60 mol d. 0.69 mol e. 1.37 mol Section 18.5 39. The pKa of acetic acid, HC2H3O2, is 4.76. A buffer solution was made using an unspecified amount of acetic acid and 0.30 moles of NaC2H3O2 in enough water to make 1.50 liters of solution. Its pH was measured as 4.50 on a meter. How many moles of HC2H3O2 were used? a. 0.31 b. 0.55 c. 0.61 d. 1.09 e. 1.21 7 Section 18.5 40. The pKa of acetic acid, HC2H3O2, is 4.76. A buffer solution was made using an unspecified amount of NaC2H3O2 and 0.30 moles of acetic acid in enough water to make 2.00 liters of solution. Its pH was measured as 4.60 on a meter. How many moles of NaC2H3O2 were used? a. 0.10 b. 0.21 c. 0.30 d. 0.42 e. 0.44 Section 18.5 41. The pKa of acetic acid, HC2H3O2, is 4.76. A buffer solution was made using an unspecified amount of NaC2H3O2 and 0.30 moles of acetic acid in enough water to make 1.50 liters of solution. Its pH was measured as 4.55 on a meter. How many moles of NaC2H3O2 were used? a. 0.10 b. 0.18 c. 0.30 d. 0.37 e. 0.49 Section 18.6 50. The pH of the blood carrying carbon dioxide to and from the lungs is of critical importance. The values of Ka1 and Ka2 for the CO2HCO3-CO32- system at body temperature are 7.9 x 10-7 and 4.7 x 10-11. What percent of the carbon dioxide being carried by the blood is actually in the form of CO2 as opposed to HCO3- if the pH of the blood carrying the respiration product to the lungs is 7.30? a. 6.0 percent b. 6.3 percent c. 7.1 percent d. 45.5 percent e. 94 percent Section 18.6 51. The pH of the blood carrying carbon dioxide to and from the lungs is of critical importance. The values of Ka1 and Ka2 for the CO2HCO3-CO32- system at body temperature are 7.9 x 10-7 and 4.7 x 10-11. What is the ratio of [CO2]/[ HCO3-] in blood if the pH of the CO2 carrying blood is 7.30? a. 0.063 to 1 b. 0.067 to 1 c. 0.077 to 1 d. 0.25 to 1 e. 0.83 to 1 8 Section 18.6 52. For H3PO3, which is actually a diprotic acid, Ka1 = 1.0 x 10-2 and Ka2 = 2.6 x 10-7. Calculate a value for the [H2PO3-] in a 0.500 molar solution of H3PO3. a. 1.0 x 10-2 mol L-1 b. 6.6 x 10-2 mol L-1 c. 7.1 x 10-2 mol L-1 d. 8.5 x 10-3 mol L-1 e. 3.3 x 10-3 mol L-1 Section 18.6 53. For H3PO3, which is actually a diprotic acid, Ka1 = 1.0 x 10-2 and Ka2 = 2.6 x 10-7. Calculate a value for the [HPO32-] in a 0.500 molar solution of H3PO3. a. 2.6 x 10-7 mol L-1 b. 6.6 x 10-2 mol L-1 c. 7.1 x 10-2 mol L-1 d. 8.5 x 10-5 mol L-1 e. 3.3 x 10-3 mol L-1 Section 18.6 54. Tenzic acid, H2Tenz, is a diprotic acid with ionization constants: Ka1 = 4.0 x 10-4, Ka2 = 1.5 x 10-9. Calculate a value for the [H+] in a 0.500 molar solution of H2Tenz. a. 1.4 x 10-2 mol L-1 b. 1.6 x 10-2 mol L-1 c. 4.0 x 10-4 mol L-1 d. 2.0 x 10-2 mol L-1 e. 4.0 x 10-2 mol L-1 Section 18.6 55. Tenzic acid, H2Tenz, is a diprotic acid with ionization constants: Ka1 = 4.0 x 10-4, Ka2 = 1.5 x 10-9. Calculate a value for the [HTenz-] in a 0.500 molar solution of H2Tenz. a. 1.4 x 10-2 mol L-1/L b. 1.6 x 10-2 mol L-1/L c. 4.0 x 10-4 mol L-1/L d. 2.0 x 10-2 mol L-1/L e. 4.0 x 10-2 mol L-1/L Section 18.6 56. Tenzic acid, H2Tenz, is a diprotic acid with ionization constants: Ka1 = 4.0 x 10-4, Ka2 = 1.5 x 10-9. Calculate a value for the [Tenz2-] in a 0.500 molar solution of H2Tenz. a. 7.7 x 10-7 mol L-1/L b. 2.7 x 10-5 mol L-1/L c. 3.8 x 10-5 mol L-1/L d. 4.0 x 10-4 mol L-1/L e. 1.5 x 10-9 mol L-1/L 9 Section 18.6 58. For H3PO3, which is actually a diprotic acid, Ka1 = 1.0 x 10-2 and Ka2 = 2.6 x 10-7. Calculate a value for the [H+] in a 0.500 molar solution of H3PO3. a. 1.0 x 10-2 mol L-1 b. 6.6 x 10-2 mol L-1 c. 7.1 x 10-2 mol L-1 d. 8.5 x 10-3 mol L-1 e. 3.3 x 10-3 mol L-1 Section 18.8 76. The pH at the equivalence point of the titration of acetic acid solution by sodium hydroxide solution is a. < 2.00 b. 3.50 < pH < 7.00 c. 7.00 d. 7.00 < pH < 11.00 e. > 11.0 Section 18.8 80. 50.0 ml of 0.10 M HCl(aq) was added to 40.0 ml of 0.10 M NaOH(aq) and the mixture was stirred, then tested with a pH meter. What reading should be obtained for the pH at 25.0 oC? a. 1.95 b. 2.00 c. 7.00 d. 12.00 e. 12.05 Section 18.8 81. 20.0 ml of 0.10 M H2SO4(aq) was added to 50.0 ml of 0.10 M NaOH(aq) and the mixture was stirred, then tested with a pH meter. What reading should be obtained for the pH at 25.0 oC? a. 1.85 b. 2.00 c. 7.00 d. 12.00 e. 12.15 Section 18.8 82. 40.0 ml of 0.20 M HCl(aq) was added to 50.0 ml of 0.20 M NaOH(aq) and the mixture was stirred, then tested with a pH meter. What reading should be obtained for the pH at 25.0 oC? a. 1.65 b. 2.00 c. 7.00 d. 12.00 e. 12.35 10 Section 18.8 83. 40.0 ml of 0.20 M HCl(aq) was added to 50.0 ml of 0.10 M NaOH(aq) and the mixture was stirred, then tested with a pH meter. What pH should be obtained at 25.0 oC? a. 0.70 b. 1.48 c. 1.65 d. 12.00 e. 12.52 Section 18.8 84. Given the following: 0.20 M NaOH(aq) 0.20 M HCl(aq) A mixture is made using 50.0 ml of the HCl and 50.0 ml of the NaOH. What is its pH at 25.0 oC? a. 3.62 b. 4.57 c. 6.30 d. 7.00 e. 9.46 Section 18.8 85. Given the following: 0.20 M NaOH(aq) 0.20 M HCl(aq) A mixture is made using 50.0 ml of the NaOH and 25.0 ml of the HCl. What is its pH at 25.0 oC? a. 7.00 b. 12.52 c. 12.82 d. 13.00 e. 13.30 Section 18.8 86. Given the following: 0.20 M NaOH(aq) 0.20 M HCl(aq) A mixture is made using 50.0 ml of the HCl and 25.0 ml of the NaOH. What is its pH at 25.0 oC? a. 1.18 b. 4.62 c. 7.00 d. 11.38 e. 12.82 Section 18.8 87. Given the following: NaOH(aq), pH = 13.301 HCl(aq), pH = 1.000 A mixture is made using 50.0 ml of the HCl and 25.0 ml of the NaOH. What is its pH at 25.0 oC? 11 a. 1.176 b. 4.622 c. 7.000 d. 7.151 e. 14.301 Section 18.8 88. Given the following: NaOH(aq), pH = 13.301 HCl(aq), pH = 1.000 A mixture is made using 50.0 ml of the HCl and 50.0 ml of the NaOH. What is its pH at 25.0 oC? a. 1.300 b. 7.000 c. 12.700 d. 13.000 e. 14.300 Section 18.8 89. A solution is made by mixing 50.0 ml of an HCl(aq) solution which has a pH of 3.00 with 50.0 ml of a KOH solution which has a pH of 11.00. What is the pH of the mixture at 25.0 oC? a. 3.35 b. 4.25 c. 7.00 d. 7.50 e. 10.65 Section 18.8 90. Given the following: NaOH(aq), pH = 13.00 HCl(aq), pH = 1.00 A mixture is made using 50.0 ml of the HCl and 50.0 ml of the NaOH. What is its pH at 25.0 oC? a. 1.30 b. 7.00 c. 12.70 d. 13.00 e. 14.30 Section 18.8 91. Given the following: NaOH(aq), pH = 13.00 HCl(aq), pH = 1.00 A mixture is made using 50.0 ml of the HCl and 25.0 ml of the NaOH. What is its pH at 25.0 oC? a. 1.30 b. 1.48 c. 3.67 d. 5.00 e. 7.00 12 Section 18.8 92. Given the following: NaOH(aq), pH = 13.00 HCl(aq), pH = 1.00 A mixture is made using 25.0 ml of the HCl and 50.0 ml of the NaOH. What is its pH at 25.0 oC? a. 1.30 b. 8.33 c. 9.00 d. 12.52 e. 12.70 Section 18.8 93. A 50.0 ml sample of an HCl(aq) solution was mixed with a 40.0 ml sample of a 0.200 molar NaOH(aq) solution. The pH of the mixture was measured and a value of 11.74 was obtained. What is the concentration of the HCl solution if the temperature is 25.0 oC? a. 0.025 molar b. 0.140 molar c. 0.150 molar d. 0.180 molar e. 0.200 molar Section 18.8 94. A solution is made by mixing 50.0 ml of a nitric acid solution which has a pH of 4.00 with 50.0 ml of an NaOH solution which has a pH of 11.00. What is the pH of the mixture at 25.0 oC? a. 7.00 b. 7.50 c. 10.35 d. 10.65 e. 10.95 Section 18.8 95. A solution is made by mixing 100.0 ml of an HCl(aq) solution which has a pH of 3.00 with 50.0 ml of a KOH solution which has a pOH of 6.00. What is the pH of the mixture at 25.0 oC? a. 3.00 b. 3.18 c. 4.50 d. 7.00 e. 9.25 Fill in the Blanks Section 18.1 96. The pKa of a weak acid is 6.50. What is the value of Ka for this acid? ______ () Section 18.2 13 14 97. A 0.100 molar solution of a moderately strong monoprotic acid in water has a pH = 1.88. Calculate the value of Ka, the acid ionization constant for this acid. ______ () Section 18.2 98. A solution of a weak monoprotic base B (0.50 M) and its salt BH+Cl- (0.80 M) has a pH = 9.40. What is the value of Kb for this base, B? ________ () Section 18.2 99. A solution of a weak monoprotic acid, HAc (0.50 molar), and its potassium salt, KAc (0.75 molar), has a measured pH = 4.88. What is the value of Ka for this acid? _________ () Section 18.7 100. Carbonic acid, H2CO3, is a diprotic acid with ionization constants: Ka1 = 4.5 x 10-7, Ka2 = 4.7 x 10-11. Calculate the pH of a 0.100 molar solution of Na2CO3, which is the sodium salt of the one of the conjugate bases of this acid. ______ () True and False Section 18.1 102. A relation involving acids and bases is, Ka + Kb = Kw. ___ () Section 18.1 103. The pKa is a reliable measure of the strength of an acid. Strong acids have larger pKa values than weak acids. ___ () Solubility and Simultaneous Equilibria Multiple Choice Section 19.1 4. The expression for the solubility product of copper(II) hydroxide is a. [Cu2+][2 OH-] b. [Cu2+] x 2[OH-]2 c. [Cu2+]2[OH-] d. [Cu2+][OH-]2 e. [Cu2+] x [OH-]2 Section 19.1 5. The expression for the solubility product of calcium fluoride, CaF2 is a. [Ca2+][2 x F-] b. [Ca2+] x 2[F-]2 c. [Ca2+]2[F-] d. [Ca2+][F-]2 e. [Ca2+] x [F-]2 Section 19.1 7. The solubility of Ag2NtO4, silver nortonate, in pure water is 4.0 x 10-5 moles per liter. Calculate the value of Ksp for silver nortonate from this data. a. 1.6 x 10-9 b. 6.4 x 10-14 c. 2.6 x 10-13 d. 4.0 x 10-5 e. 4.0 x 10-15 25. The solubility product for PbCl2 is 1.7 x 10-5. What is the solubility of PbCl2 in pure water, in moles per liter? a. 2.4 x 10-4 mol L-1 b. 6.2 x 10-2 mol L-1 c. 7.7 x 10-3 mol L-1 d. 1.6 x 10-2 mol L-1 e. 6.0 x 10-5 mol L-1 Section 19.1 26. Calculate the concentration of chloride ions in a saturated solution of lead(II) chloride. The Ksp = 1.7 x 10-5. a. 2.4 x 10-4 M b. 4.8 x 10-4 M 419 420 c. 3.9 x 10-2 M d. 1.2 x 10-1 M e. 3.2 x 10-2 M Fill in the Blanks Section 19.1 80. A precipitate will form when an anion solution and a cation solution are mixed if the _____________ exceeds the value of the ________________________ () Section 19.1 81. Addition of a common ion to a solution of a slightly soluble salt will __________ the solubility of the slightly soluble salt. () Section 19.1 82. The pH of a saturated solution of Mg(OH)2, whose Ksp is 7.1 x 10-12, is ______ () Section 19.1 83. The pH of a saturated solution of Ca(OH)2 is 12.37. What is the Ksp of Ca(OH)2? ______ () Section 19.4 93. Even though silver chloride is only very very slightly soluble in water, addition of a reagent which forms complexes with silver increases this solubility. ___ ( ) Critical Thinking Section 19.1 94. A saturated solution of silver nortonate, Ag2NtO4, in water contains 72 ppm of silver. What is the Ksp of Ag2NtO4? ____________ () Section 19.1 95. A saturated solution of silver nortonate, Ag2NtO4, in water contains 72 ppm of silver. How many parts per million of silver would there be in a 1.00 molar aqueous solution of Na2NtO4 which has been saturated with silver nortonate? ______ () Thermodynamics Multiple Choice Section 20.1 1. The mathematical equation below which expresses the first law of thermodynamics is a. H = E + pV b. H = E - pV c. H = q + w d. E = q + w e. H = q + E Section 20.1 2. The mathematical equation below which expresses the first law of thermodynamics is a. H = H + w b. E = q + w c. E = q - H d. E = q + H e. H = E - pV Section 20.1 4. The standard enthalpy of reaction, Horxn, for NH3(g) + HCl(g) NH4Cl(s) is -175.9 kJ mol-1. Determine the value of Eorxn for this reaction. a. -164.8 kJ mol-1 b. -170.9 kJ mol-1 c. -173.4 kJ mol-1 d. -180.9 kJ mol-1 e. +5134 kJ mol-1 Section 20.1 5. The standard enthalpy of reaction, Horxn, for the reaction, C4H10(g) + 13/2 O2(g) 4 CO2(g) + 5 H2O(l) is -2877 kJ mol-1. Determine the value of Eorxn for this reaction. a. -2868 kJ mol-1 b. -2871 kJ mol-1 c. -2880 kJ mol-1 d. -2886 kJ mol-1 e. +2886 kJ mol-1 Section 20.1 6. The standard enthalpy of reaction, Horxn, for the reaction, 442 CaO(s) + SO3(g) CaSO4(s) is -401.5 kJ mol-1. Determine the value of Eorxn for this reaction. a. -362.2 kJ mol-1 b. -399.0 kJ mol-1 c. -404.0 kJ mol-1 d. -2880 kJ mol-1 e. +2077 kJ mol-1 Section 20.1 7. The internal energy of a system, Esystem, can be expressed in terms of other system variables. Which one of the expressions below correctly expresses the definition of internal energy of a system, Esystem? (KE = kinetic energy, ME = mechanical energy, EE = electrical energy, TE = thermal energy, PE = potential energy) a. Esystem = (TE)system (PE)system b. Esystem = (PE)system + (TE)system c. Esystem = (ME)system + (TE)system d. Esystem = (KE)system (PE)system e. Esystem = (KE)system + (PE)system Section 20.1 8. The internal energy of a system, Esystem, can be expressed in terms of other system variables. Which one of the expressions below correctly expresses the definition of internal energy of a system, Esystem? (KE = kinetic energy, ME = mechanical energy, EE = electrical energy, TE = thermal energy, PE = potential energy) a. Esystem = (TE)system + (KE)system b. Esystem = (KE)system + (PE)system c. Esystem = (PE)system - (KE)system d. Esystem = (PE)system + (TE)system e. Esystem = (TE)system - (PE)system Section 20.2 9. Which one of the following statements is true? a. Spontaneous changes are always accompanied by an increase in the entropy of the system. b. Spontaneous changes are always accompanied by a decrease in the entropy of the system. c. Spontaneous changes are always accompanied by an increase in the enthalpy of the sys-tem. d. Spontaneous changes are always accompanied by a decrease in the enthalpy of the system. e. Most highly exothermic chemical reactions are also spontaneous chemical reactions. Section 20.3 10. Which one of the processes below is the one which is accompanied by an increase in entropy? a. setting up a stack of dominos 443 b. setting up decorations on a Christmas tree c. filing correspondence in file folders and placing them in hanging file folders d. dropping a glass pane on the front walk of your residence e. restocking a canned goods shelf display in a supermarket Section 20.3 15. Which one of the following processes is accompanied by a decrease in the entropy of the system? a. the mixing of one liter of water with one liter of ethylene glycol to produce one liter of an antifreeze solution b. the breaking of a large rock into very many smaller pieces of crushed gravel c. the thawing of the frozen orange juice concentrate which was left in the car d. the spontaneous chemical reaction of TNT (a solid chemical compound) wherein it decomposes into several simple compounds, some of which are gaseous e. the absorption of odorous gaseous compounds by the charcoal filter in your home central air cleaning unit Section 20.4 16. Which statement below is always true for a spontaneous chemical reaction a. Ssys + Ssurr = 0 b. Ssys + Ssurr < 0 c. Ssys + Ssurr > 0 d. Ssys - Ssurr = 0 e. Ssys - Ssurr < 0 Section 20.4 19. The criterion for a spontaneous chemical reaction is a. G = 0 b. H > 0 c. S = 0 d. E > 0 e. G < 0 Section 20.4 20. As electrical energy is withdrawn from an automobile storage battery, which one of the following occurs in the storage battery? a. G decreases b. G increases c. G does not change d. E increases e. H increases 444 445 True and False Section 20.3 70. Any event which is accompanied by an increase in entropy of the system will always occur spontaneously. ___ () Section 20.3 71. The standard entropy, So for an element in its standard state is always zero. ___ () Section 20.4 72. The equation, Horeaction = Hof (products) - Hof (reactants) is a statement of the second law of thermo-dynamics. ___ Section 20.5 73. A negative value for the standard molar entropy, So, of a chemical substance indicates that the sub-stance is unstable and may decompose or detonate if mishandled. ___ () Section 20.5 74. The entropy of a solid amorphous substance at absolute zero is 0 according to the third law of ther-modynamics. ___ ( ) Section 20.8 75. Three factors which, acting together, determine whether a reaction is spontaneous or not, are en-tropy, internal energy, and enthalpy. ___ ( Electrochemistry Multiple Choice Section 21.1 1. An electrolyte is (the best answer, please) a. a solute which conducts electrical energy b. an inert electrode which conducts electrical energy c. a metal which conducts electrical energy through a solution d. a pure liquid or solution, containing ions, which conducts electrical energy e. a solution which conducts electricity Section 21.1 2. Anions a. are charged ions which move toward the anode of an electrolysis cell b. are charged ions which move toward the negative electrode of an electrolysis cell c. are charged ions which move toward the north pole of a magnetic field d. are positively charged ions which result from electrical discharge in a liquid solution e. are ions which attach themselves to any electrode to react chemically during electrolysis Section 21.1 3. Cations a. are negatively charged ions which result from electrical discharge in a liquid solution b. are charged ions which move toward the cathode of an electrolysis cell c. are charged ions which move toward the positive electrode of an electrolysis cell d. are charged ions which move toward the south pole of a magnetic field e. are ions which attach themselves to any electrode to react chemically during electrolysis Section 21.1 4. A galvanic cell has two electrodes. Which statement below is correct? a. Oxidation takes place at the anode, which is positively charged. b. Oxidation takes place at the anode, which is negatively charged. c. Oxidation takes place at the cathode, which is positively charged. d. Oxidation takes place at the cathode, which is negatively charged. e. Oxidation take place at the dynode, which is uncharged. Section 21.1 5. A galvanic cell has two electrodes. Which statement below is correct? a. Reduction takes place at the anode, which is positively charged. b. Reduction takes place at the anode, which is negatively charged. c. Reduction takes place at the cathode, which is positively charged. d. Reduction takes place at the cathode, which is negatively charged. e. Reduction takes place at the dynode, which is uncharged. 465 Section 21.1 6. Which choice correctly presents the anode reaction in the galvanic cell with the cell reaction, Nt(s) + Ag+(aq) Nt2+(aq) + Ag(s) a. Nt2+(aq) + 2 e- Nt(s) b. Ag+(aq) + e- Ag(s) c. Nt(s) Nt2+(aq) + 2 ed. Ag(s) Ag+(aq) + ee. 2H+(aq)+ 2 e- H2(g) Section 21.1 7. The electrode for which the standard reduction potential of 0.00 V is assigned, making it the electrode designated as the standard reference electrode is a. Zn2+(aq) + 2e Zn(s) b. Cu2+(aq) + 2e Cu(s) c. Ag+(aq) + e Ag(s) d. 2 H+(aq) + 2e H2(g) e. 2 NH4+(aq) + 2e H2(g) + 2 NH3(g) Section 21.1 8. The electrode for which the standard reduction potential of 0.00 V is assigned, making it the electrode designated as the standard reference electrode is a. Cd2+(aq) + 2e Cd(s) b. 2 H+(aq) + 2e H2(g) c. Ag+(aq) + e Ag(s) d. Au3+(aq) + 3e Au(s) e. 2 NH4+(aq) + 2e H2(g) + 2 NH3(g) Section 21.1 9. A galvanic cell consists of a Cu(s)/Cu2+(aq) half cell and a Zn(s)/Zn2+(aq) half cell connected by a salt bridge. Oxidation occurs in the zinc half cell. The cell can be represented in cell notation as a. Cu(s)/Cu2+(aq)/Zn(s)/Zn2+(aq) b. Zn(s)/Zn2+(aq)//Cu(s)/Cu2+(aq) c. Cu2+(aq)/Cu(s)//Zn(s)/Zn2+(aq) d. Zn(s)/Zn2+(aq)// Cu2+(aq)/Cu(s) e. Zn2+(aq)/Zn(s)//Cu(s)/Cu2+(aq) 466 14. Using these metal ion/metal standard reduction potentials Cd2+(aq)/Cd(s) Zn2+(aq)/Zn(s) Ni2+(aq)/Ni(s) Xp+(aq)/Xp(s) Cu2+(aq)/Cu(s) -0.40 v -0.76 v -0.25 v +0.62 v +0.34 v Calculate the standard cell potential for the cell whose net reaction is Cu2+(aq) + Cd(s) Cd2+(aq)+ Cu(s) a. +0.76 volt b. +0.06 volt c. -0.06 volt d. +0.74 volt e. +0.20 volt Section 21.2 15. Using these metal ion/metal standard reduction potentials Cd2+(aq)/Cd(s) Zn2+(aq)/Zn(s) Ni2+(aq)/Ni(s) Xp+(aq)/Xp(s) Cu2+(aq)/Cu(s) -0.40 v -0.76 v -0.25 v +0.62 v +0.34 v Calculate the standard cell potential for the cell whose net reaction is Ni2+(aq) + Zn(s) Zn2+(aq)+ Ni(s) a. +0.51 volt b. -1.02 volt c. -1.01 volt d. +1.01 volt e. -0.51 volt Section 21.2 16. Using these metal ion/metal reaction potentials Cu2+(aq)/Cu(s) Ag+(aq)/Ag(s) Co2+(aq)/Co(s) Nt2+(aq)/Nt(s) Zn2+(aq)/Zn(s) +0.34 v +0.80 v -0.28 v -1.10 v -0.76 v Calculate the standard cell potential for the cell whose net reaction is Nt(s) + Ag+(aq) Nt2+(aq) + Ag(s) a. -0.300 volt b. +0.300 volt c. -1.90 volt d. +1.90 volt e. +2.70 volt 467 Sections 21.3 34. Which statement is true in regard to a galvanic cell? a. Eo for the cell is always positive. b. Eo for the cell is always negative. c. The standard reduction potential for the anode reaction is always positive. d. The standard reduction potential for the anode reaction is always negative. e. The standard reduction potential for the cathode reaction is always positive. Sections 21.4 35. The unit of electrical energy used in our work is the a. ampere b. coulomb c. joule d. volt e. watt Section 21.4 36. A unit of electrical charge used in our work is the a. ampere b. coulomb d. joule c. volt e. watt Section 21.4 37. The Faraday is a unit of a. capacitance b. current c. power d. pressure e. quantity of electrical charge Section 21.4 38. One equivalent of electrical charge contains a. 4.184 joules b. 3,600 coulombs c. 23,060 joules d. 96,485 coulombs e. 3.47 x 108 coulombs Section 21.4 39. A galvanic cell is composed of these two half cells, with the standard reduction potentials shown 468 469 Co2+(aq) + 2 e- Co(s) -0.28 volt Cd2+(aq) + 2 e- Cd(s) -0.40 volt What is the standard free energy for the cell reaction of this galvanic cell? a. -12 kJ b. +12 kJ c. -23 kJ d. +23 kJ e. -46 kJ Section 21.4 40. A galvanic cell is composed of these two half cells, with the standard reduction potentials shown Cu2+(aq) + 2 e- Cu(s) +0.34 volt Cd2+(aq) + 2 e- Cd(s) -0.40 volt What is the standard free energy for the cell reaction of this galvanic cell? a. +12 kJ b. -12 kJ c. +143 kJ d. -143 kJ e. -71 kJ Section 21.4 41. A galvanic cell is composed of these two half cells, with the standard reduction potentials shown Zn2+(aq) + 2 e- Zn(s) -0.76 volt Cd2+(aq) + 2 e- Cd(s) -0.40 volt What is the standard free energy for the cell reaction of this galvanic cell? a. -69 kJ b. +69 kJ c. -224 kJ d. +224 kJ e. -35 kJ 48. A galvanic cell is composed of these two half cells, with the standard reduction potentials shown Co2+(aq) + 2 e- Co(s) -0.28 volt Cr3+(aq) + 3 e- Cr(s) -0.74 volt The actual concentrations are: Co2+(aq) = 0.0100 M, Cr3+ = 0.00100 M. What is the actual poten-tial of this galvanic cell? a. +0.40 volt b. +0.46 volt c. +0.52 volt d. +0.54 volt e. +1.02 volt Section 21.5 49. A galvanic cell is composed of these two half cells, with the standard reduction potentials shown Co2+(aq) + 2 e- Co(s) -0.28 volt Cr3+(aq) + 3 e- Cr(s) -0.74 volt The actual concentrations are: Co2+(aq) = 0.00100 M, Cr3+ = 0.100 M. What is the actual potential of this galvanic cell? a. +0.33 volt b. +0.39 volt c. +0.45 volt d. +0.94 volt e. +1.61 volt Section 21.5 50. A galvanic cell is composed of these two half cells, with the standard reduction potentials shown Co2+(aq) + 2 e- Co(s) -0.28 volt Cr3+(aq) + 3 e- Cr(s) -0.74 volt The actual Co2+(aq) concentration is 0.00100 M, while the Cr3+(aq) concentration is unknown. The actual cell potential measured 0.38 volts. What is the actual concentration of the Cr3+ ion in the cell? a. 0.00180 M b. 0.00500 M c. 0.0090 M d. 0.0360 M e. 0.360 M Facets of Chemistry 21.1 103. Iron objects such as storage tanks and underground pipelines can be protected from corrosion by connecting them via a wire to a piece of: a. copper b. lead c. magnesium d. silver e. tin Facets of Chemistry 21.1 104. Steel objects which are exposed to weather can be protected from corrosion by a coating of ______, a process which is called galvanizing. a. copper b. lead c. tin d. cobalt e. zinc 470 471 Fill in the Blanks Section 21.6 105. In the lead storage battery, the electrolyte is ______________________ () True and False Section 21.2 109. The SI unit of charge is the Faraday. ___ () ... View Full Document

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