Pract-MT1_3_key

Pract-MT1_3_key - Midterm 1 ...

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Unformatted text preview: Midterm 1 Name______________________________ Signature___________________________ Tuesday, October 26th, 2010 Dr. Kroner, Chemistry 121 7:30  ­8:48 pm Lab. Instructor______________________ Rec. Instructor______________________ EXAM INSTRUCTIONS 1. Fill out answer sheet as follows, using pencil only. (Ink not read by machine). See Supplemental Info Handout for the instructions to record your name, section number (below), and SIS/Carmen ID Number on Scan Sheet. 2. Find the day, time, and TA of your own lab session and enter it on your Scan Sheet as requested on the Supporting Information Handout: Tuesday 8:30 Yingying Zeng Josh Wieting Kimberly Stephany Kelsey Miles Daniel Adu ­Ampratwum Antony Okumu Tuesday 11:30 Ashley Altman Steven Lim Bryan Albani Martin Beres Danny Liu Zhou Lin 36 37 38 39 40 41 50 51 52 53 54 55 Wednesday 11:30 Hao Chi 42 Gina Spizzirri 43 Thursday 11:30 Bryan Albani Martin Beres Danny Liu David Crister Teresa Kuo Jason Young 56 57 58 59 60 61 Thursday 8:30 Kimberly Stephany Kelsey Miles Daniel Adu ­Ampratwum Josh Wieting Antony Okumu Yingying Zeng Friday 2:30 Allison Gapinski Taylor Conway 44 45 46 47 48 49 62 63 3. When the proctors give the signal, check to see that there are 10 total pages in this exam booklet, including this cover page. 4. There are 35 multiple ­choice questions for a total score of 175 points. All questions are equally weighted. Always give the best possible answer. 5. You must mark answers on the answer sheet in PENCIL ONLY. Fill in all answers COMPLETELY with PENCIL. If you wish to change an answer, erase the unwanted mark COMPLETELY. 6. Only the marks on the Scan Sheet are graded and not those in your exam booklet. Extra time is NOT given to transfer your answers to the Scan Sheet. 7. Only approved calculators can be used – all other electronic devices are forbidden. 8. The time allowed for this exam is 1 hour, 18 minutes (78 total minutes). 9. At the end of the examination, you must hand in the Scan Sheet before leaving the room. You may keep the exam booklet unless taking an alternate or make ­up exam. Page 1 of 10 All questions are worth 5 points. Always give the best possible answer. 1. A block of a pure metal with a mass of 3.50 g is added to a graduated cylinder, which causes the water level to rise from 26.20 mL to 27.50 mL. Using table of densities below, which element could be the metal in the block? Metal Al Fe Ni Ti Zn Density (g/cm3) 2.70 7.86 8.91 4.50 7.14 a. b. c. d. e. Al Fe Ni Ti Zn 2. Which following measurement must have exactly four significant figures? a. 0.0250 b. 0.2500 c. 250.0 d. Both a and b e. Both b and c 3. How many significant figures does the result of this calculation contain? 15.55 m − 4.2 m 39.455 s + 63.98 s a. 2 b. 3 € c. 4 d. 5 e. None of the above 4. Determine which conversion factor(s) below is/are correct? a. 1 g/mL = 1 mg/mm3 b. 1 g/mL = 1 mg/cm3 c. 1 g/mL = 1 mg/m3 d. 1 g/mL = 1 kg/m3 e. More than one of the above Page 2 of 10 5. Which of the following terms best describes salt water? a. Homogenous solution b. Heterogeneous solution c. Pure compound d. Pure element e. None of the above 6. Which of the following measurements are identical? a. 1.25 m and 1.25x10–12 pm b. 8.32 mL and 8.32x106 µL c. 5.19 kg and 5.19x1012 ng d. All of the above measurements are identical e. None of the above measurements are identical 7. Which atom has the most number of neutrons? a. An atom with an atomic number of 28 and a mass number of 59 b. An atom of Manganese with a mass number of 55 c. Iron ­56 d. 52Cr e. All of the above have an equal number of neutrons. 8. Which ion contains exactly 20 protons and 18 electrons? a. K+ b. K– c. Ca2+ d. Ca2– e. None of the above 9. What compound forms between the most common ions of rubidium and sulfur? a. RbS b. Rb2S c. RbS2 d. RuS e. Ru2S Page 3 of 10 10. Which of the statements are true? a. HClO4 and K2SO4 are ionic compounds b. NO and N2O5 are binary compounds c. CH3CH2OH and C6H12O6 are molecular compounds d. Both b and c are correct e. All of the above are correct 11. Which of the following name ­formula pair(s) is/are INCORRECT? I. Fe2O3 = Iron(II) oxide II. Ca(OH)2 = calcium hydroxide III. Na2O2 = Sodium oxide IV. K2Cr2O7 = Potassium dichromate V. LiN3 = Lithium nitride a. III only b. I and II c. III and IV d. I, III, and V e. I, IV, and V 12. Which of the following compounds has the name cobalt(III) chlorite? a. Co3(ClO2)3 b. Co(ClO2)3 c. Co(ClO3)3 d. Co(ClO4)3 e. Co3(ClO4)3 13. Which pair of compounds are hexane and butanol, respectively? a. CH3CH2CH2CH2CH3 and CH3CH2CH2CH2OH b. CH3CH2CH2CH2CH2CH3 and CH3CH2CH2CH2CH2OH c. CH3CH2CH2CH2CH2CH2CH3 and CH3CH2CH2OH d. CH3CH2CH2CH2CH2CH3 and CH3CH2CH2CH2OH e. None of the above 14. Which acid is correctly named? a. Bromic acid = HBrO3 b. Phosphorous acid = H3PO3 c. Hydroiodic acid = HI d. Both a and b are correct e. All of the above are correct Page 4 of 10 15. Copper has two naturally ­occurring isotopes, the predominant one being 63Cu with an isotopic weight of 62.9296 amu and an abundance of 69.150%. What is the mass of its other naturally ­occurring isotope? a. 61.821 amu b. 63.546 amu c. 63.982 amu d. 64.529 amu e. 64.928 amu 16. The empirical formula of an ionic compound has 3 Cl– ions per metal ion. A 1.892 g sample of the substance is dissolved in water and is treated with excess AgNO3 (aq), which leads the formation of AgCl (s) precipitate. If 5.017 g of precipitate is formed, what is the identity of the ionic compound? a. FeCl3 b. ScCl3 c. AsCl3 d. YCl3 e. LaCl3 17. Acrylic acid, used in the manufacture of acrylic plastics has the composition 50.0% C, 5.6 % H and 44.0% O, by mass. What is its empirical formula? a. C2H2O b. C2H4O2 c. C3H4O2 d. CH2O e. C2HO Page 5 of 10 18. A 0.2358 g sample of nicotine, which contains only carbon, nitrogen, and hydrogen, is burned in excess oxygen in a combustion analysis experiment, yielding 0.1839 g of H2O and 0.6391 g of CO2. The molecular formula of nicotine was found in a separate experiment to contain two empirical units. What is the molecular formula of nicotine? a. C6H10N2 b. C6H12N4 c. C8H14N2 d. C8H18H2 e. C10H14N2 19. Which of the following statements is correct? a. One molecule of H2O has a mass of 18.02 g b. One mole of H2O has a mass of 18.02 g c. One molecule of H2O has a mass of 2.992x10–23 g d. Both a and b are correct e. Both b and c are correct 20. How much zirconium (in g) is in 0.338 mol of the mineral zircon, ZrSiO4? a. 0.620 g b. 3.08 g c. 6.20 g d. 30.8 g e. 62.0 g Page 6 of 10 21. What are the products of the decomposition reaction caused by the heating of zinc (II) carbonate? a. Zn (s) + CO2 (g) b. ZnO (s) + CO2 (g) c. Zn(OH)2 (aq) and H2CO3 (aq) d. ZnO2 (s) + CO (g) e. None of the above 22. Which statement is NOT true concerning the combustion of methane in the presence of excess oxygen? Assume the reaction yield is 100%. a. The reaction of 16.0 g of CH4 will produce 2.00 moles of water b. The reaction of 16.0 g of CH4 will produce 36.0 g of water c. The reaction of 32.0 g of O2 will produce 44.0 g of carbon dioxide d. One molecule of CH4 reacts with two molecules of oxygen e. 1.00 mole of CH4 will produce 44.0 g of carbon dioxide 23. If 19.5 g of sodium and 46.9 g of chlorine react via a combination reaction, how much excess reactant (in g) remains when the reaction is 100% complete? a. 16.8 g chlorine remains b. 13.2 g chlorine remains c. 10.9 g sodium remains d. 4.3 g sodium remains e. Neither reactant remains 24. Consider the metathesis reaction between Pb(NO3)2 (aq) and KI (aq), in which a precipitate is formed and is separated from the supernatant solution. Which test and observation on the solution allows a definitive conclusion that Pb(NO3)2 is present as the excess reactant? a. Precipitate forms when additional Pb(NO3)2 (aq) is added b. No precipitate forms when additional Pb(NO3)2 (aq) is added c. Precipitate forms when additional KI (aq) is added d. No precipitate forms when additional KI (aq) is added e. A solid is observed after evaporating off all the water Page 7 of 10 25. Chlorobenzene, C6H5Cl, is produced by the reaction below in 73% yield. How much benzene, C6H6, (in kg) is required to produce 775 g of chlorobenzene in the presence of excess chlorine? C6H6 (l) + Cl2 (g) C6H5Cl (l) + HCl (g) (73% yield) a. 538 g b. 565 g c. 675 g d. 737 g e. 775 g 26. Which precipitate forms when CaBr2 and AgC2H3O2 are mixed in water? a. AgBr2 b. AgBr c. Ag2Br d. Ag2Br2 e. No precipitate forms 27. Which of the following compounds is/are soluble in water? a. K3PO3 b. NaIO4 c. (NH4)2SO3 d. All of the above e. None of the above 28. Which of the following is/are weak electrolytes in water? a. Mg(OH)2 b. H3PO4 c. HClO4 d. Both a and b e. Both b and c 29. Which molecule ­property pair is correct? a. HCl (aq) = strong base b. NH4OH (aq) = weak acid c. NH3 (aq) = weak base d. Ca(OH)2 (aq) = strong acid e. More than one of the above is correct Page 8 of 10 30. How much volume (in mL) of 0.75 M K2SO4 (aq) and water must be mixed to prepare to 150.0 mL of 0.10 M K2SO4 solution? a. 130.0 mL of K2SO4 and 20.0 mL H2O b. 20.0 mL of K2SO4 and 150.0 mL H2O c. 150.0 mL of K2SO4 and 20.0 mL H2O d. 20.0 mL of K2SO4 and 130.0 mL H2O e. None of the above 31. Generally, the conductivity of a solution is directly proportional to the number of ions in the solution. Which solution below would generally be predicted to have the lowest conductivity? a. 0.600 M KBr (aq) b. 0.500 M K2CO3 (aq) c. 0.400 M K3PO4 (aq) d. 0.300 M Fe2(SO4)3 (aq) e. 0.250 M Cr(NO3)6 (aq) 32. A 5.00 mL sample of cider vinegar, which contains acetic acid (CH3COOH), is titrated with 0.1198 M NaOH solution. If 33.93 mL of the NaOH solution is required to reach the end point of the titration, what is the concentration (in M) of acetic acid in the cider vinegar sample? a. 0.408 M b. 0.548 M c. 0.615 M d. 0.722 M e. 0.813 M Page 9 of 10 33. Which molecule contains an atom with an oxidation number of +4? a. N2O4 b. NaO2 c. OF2 d. KClO2 e. None of the above 34. Which reaction below is an example of a redox reaction? a. Pb(NO3)2 + 2 KCl PbCl2 + 2 KNO3 b. C2H5OH + 3 O2 2CO2 + 3 H2O c. N2 + 3 H2 2 NH3 d. Both b and c e. All of the above 35. Which statement below is/are true? a. Na (s) can be oxidized to Na+ (aq) with Cu(NO3)2 (aq) b. Na (s) can be reduced to Na+ (aq) with Cu(NO3)2 (aq) c. Cu (s) can be oxidized to Cu2+ (aq) with NaNO3 (aq) d. Cu (s) can be reduced to Cu2+ (aq) with NaNO3 (aq) e. Both statements a and d are true Page 10 of 10 ...
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