Answer Key Exam 1 F10 Form A

Answer Key Exam 1 F10 Form A - AN$W€K K57 A PageO Part 1...

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Unformatted text preview: AN$W€K K57 A PageO Part 1 (40 points) Multiple choice. Place your best answer on the answer sheet. Points as indicated. 1. (3 pts) Using the phase diagram of carbon below which marked point has the highest kinetic energy? ,,,, .a/ 7 (A) point A (B) pointB (C) point C /B \ (D) points B and C @points A, B and C Alt {701,075 AWE A7” WW M We ° so ALL mm; 17% 5% 4’95 V 2. (3 pts) Based on your laboratory experience and the data below, which metal will float on mercury? mam <——» max I? (MR6? . ’ 51,—??? Mass Mercury Lead é“ Afl‘figj/f ‘ C55") 6) (A : s poYK Volume (A) Platinum because it is more ex ensive p 176/05/77 c W/v (B) Platinum because it has a lower density than Mercury 0 7L 5 La, ? (C) §ad because it has a lower density than Mercury .,, ‘ C Lt «15> M6 fl (D) Both will sink, because they are more dense than water A. w all '1) flew/L) (E) Neither will float, because they are too dense % 5o / 7/ 59/44” Page 1 For questions 3, 4 and 5 consider the following microscopic representation of matter: 3. (3pts) Are steps I and 11 physical or chemical processes? (A) I —~ chemical; II — physical (B) I — (C) I - Chemical ; H — Chemical (D) I — physical; II — chemic (E) not enough information 4. (3pts) Are states A, B and C homogeneous or heterogeneous? (A) state A is homogenous, B and C are heterogeneous (B) states A and B are homogeneous, C is heterogeneous (C) states A, B and C are all heterogeneous tate A is heterogeneous, B is homogeneous, C is heterogeneous 5. (3pts) Which diagram at the top of the page is a representation of a “pure substance”? A 1A EB: 2:13:13 AM— waif/gag, @oniy 0 7902177 c gc 5. (D) AandC [’6' [5 79 SéLID <1“ (E)Bandc L/Qa/p OF 7796 SW SaBéfl/OC‘?‘ o. Page 2 The oil that causes the skin rash from Poison Ivy is called urushiol and is a member of a family of compounds based on catechol ( benzene-1.2-diol), as shown below. _ Structure of Catechol: H 1 OH Based on this structure, answer the following questions 6 through 9. 6. (2 pts) What is the correct molecular formula of catechol? (A) CHO (B) (3sz o (D) C3H3O 51w ?L%757‘ Lactate: Umfi‘é’d gar/i 77 a 7. (2 pts) What is the correc@formula? (A) CH0 (B) (3sz o (c) C6H602 @7 <2 *4/53; = (52> [430 g :3 2“ 8. (2 pts) What is the olar mass f catechol in grams/mo]? (C= 12. g/mol, H: 1.0 élmol, O = 16. g/mol, N=14. g/mol, Cl=35.5 g/mol, Br = 80. g/mol) (A) 165 t ( (B@ (C) 55 (D) 158.5 = Cl?» ~ 4H 5 2 :: C(123+((/'a> (- O a 0 ~ Z 0 6) 9. (4 pts)‘If a typical poison ivy leaf has 150. I of catecol how many MOLECULES of catechol are present? (A) 8.21><1o20 (B) 8.21><1023 (C) 1.36><10'3 (D) 6.022><1o23 3 (50.0 ""01? mafia» k [if—[5" §< é'oz'zk/OL uqda’é'“ 07 No.3 ‘wo( ~2c: -: 8.2/X/6 to»! V5” 2.6 ., 6K Vz‘Vt “(/f Z l ( Page 3 10. (3 pts) Ind‘ - y- ‘ e’ a gram most closely re weather balloon coming down, when the external 1 and the t perature (K) doub s. VAéU 1 2 Initial Gas The final state is: (A) 1 (C) 3 (D) need more data 11. (2 pts) You are given 124 grams of NazCr207 (MlVI = 262'g/mole). How many moles of the compound do you have? (B) 0.237 (C) 3.25 x104 (D) 2.11 Wbbéji :. é 514% ZélgflqD/e) 12. (3 pts) A compound has the formula A2X3Y5. From a sample you extract 6 moles of X. How many moles of A and Y must you also have? 1 (A) A=2 Y=5 (B) A= 4 Y= o (C) A= 12 Y: 60 (D) A=1 Y: 2.5 M J. 1:320 +273 = 2324. age: 13. (3pts) A sample of an ideal gas has a volume of 3.50 L at 11.20 C and 1.40 atm. What is the volume of the gas at 18.20 C and 0.993 atm? (A) 8.02L 1‘ (B) 2.22L (C) 2.76L 77:12.2M27245‘; 27/29? - a > £9 \192, (if! = 5.501. cm Gal-as” : S-O'Sé \//7Efls «9?; We “£2773; Page 4 14. (4 pts) The temperature and volume are the same in the three boxes below. Assume the mass is proportional to the size of the particle. Which box has the highest pressure? (A) 1 (B) 2 @ (D) land 3 -(E) all are the same m ,.. vaflll (F V)? A116 woéfiw‘r‘ Tag/U For 71/ 1440725 PfiRT/Qfé IMDPE Pfle’sM/flg mg, Wpé 3% M K5 3”T@ W5 Maflg 7577216, Kg Page 5 Part 2 (60 points) Instructions for PART 2: Put your ENTIRE answer, for each of the following three problems, on the back of the optical scanning sheet (in the boxes given for each problem). NOIflmG will be graded that is on this sheet of paper. In order to receive partial credit, you MUST Show computations. No work means no creditl 1. (20 pts) A substance X has a normal boiling point of 150 K and a normal melting point of 90.0 K Its critical temperature is 175.0 K and critical pressure is 2.0 atm. It has a triple point at 60.0 K and 0.50 atm. as) Sketch the phase diagram. Label the axes, the phase regions, the normal melting and boiling points, and the triple point. l 197 Which phase is present at P= 2.2 atm T= 190K? 4.) Does solid substance X float or sink in its own liquid? Why? Describe the changes whgrou go directly from P= 0.25 atm ~T= 100K to P= 2.0 atm '1‘: 100K 3 c.) sosz MAJ/<5 2W5 WW ézs SOL/9 [5 “fit/M 977992.365 54‘; I? 4* ’5 tub/lg Pct/9066 (5w Page 6 [Put your ENTIRE answer on the back of the optical scanning sheet] 2. (20 pts) You have a mixture of nitrogen gas ( BP 77K) and oxygen gas ( BP 90 K) at room temperature. (a) (8 pts) Propose a method of separation and the differentiating characteristic. More than one answer is possible. (4 points separation methotD a) You could cool the gases to make a liquid and then distill the liquid boiling of the N2 first. (4points differentiating characteristic) Boiling points b) You could slowly cool the mixture and the 02 would condense first . The BP is the differentiating characteristic. c) You could use Chromatography aml the differentiating characteristic is the affinity of the gases for the stationary phase in the column. Use good chemical sense in explaining what is going on (b) (12 pts) Using the particulate model of matter explain why your proposed method of separation would work. Again there are several possible answers. The explanation must be consistent at the molecular level with the separation method given above General Scoring method 12 pts 7— complete and clear answer using PARTICLES 8pts -some key element missing( identity it), but generally chemically sound 4pts- some ideas present but not unified or organized 0 pts- lacking any insight in the particle nature of the problem N0 PARTICLES no explanation at the molecular level --no points. General Key concepts — read their answers for the “ideas” There must be different forces acting between 02 molecules with themselves and N2 molecules with themselves. 02 must have stronger intermolecular forces since it has a higher BP If we lower the temperature the speed of the particles decreases so the intermolecular forces can take hold and a liquid will form. With stronger forces the 02 will liquefyfirst then the N2. When distilling the average kinetic energy increases for both, but the N2 will boil first BE CA USE of weaker intermolecular forces and separate from the 02. BP is not the explanation, but the differentiating characteristic. This answer must contain molecular level insight. Page 7 [Put your ENTIRE answer on the back of the optical scanning sheet] (20pts) Coritsol (M = 362.47 g/mol), one of the major steroid hormones, is a key factor in the synthesis of protein. Its profound effect on the reduction of inflammation explains its use in the treatment of rheumatoid arthritis. Cortisol is 69.6% C, 8.34% H, and 22.1% its empirical and molecular formulas? (molar masses C= 12.01 g/mol H= 1.008 g/mol and O = 16.00 g/mol) g 9. e ETSiW“ 5‘77fi7mlfi C42 H45 H viii/2 t, $474M {may} (:2) # l _ 'é’Wé/a g: to: 0 £3313» v1.53] 47’ _ mag/k1 M XS €519.53 45.274 0/. 91 "57’ [355“! 55/ (39/. m “3.77 0/ 0 by mass. What are ...
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Answer Key Exam 1 F10 Form A - AN$W€K K57 A PageO Part 1...

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