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Final Exam CHE 132 Fall 2018

Form 1A

Multiple Choice On the Scantron form, bubble in the letter of the one choice that best completes the statement or answers the question. No credit will be given for multiple answers. ____

1. Which one of the following is the chemical formula of the compound potassium diaquatetracyanoferrate(III) ? A. [Fe(CN)4(OH2)2]K B. C.

[FeK(CN)2(OH2)2](CN)2 K 2[Fe(CN)4(OH2)2] D. K 2[FeK(CN)4(OH2)2]+ E.

____

K[Fe(CN)4(OH2)2]

2. What is the coordination number of the transition metal in the compound potassium dichloroethylenediamineoxalatocobaltate(III)? A. 2 B. 3 C.

4

D. 6 E.

____

8

3. How many geometric isomers does a square-planar transition metal complex with formula [PtBr(CN)(NH3)2] have? A. 1 B. C.

2 3

D. 4 E.

6

Final Exam, CHE 132 Fall 2018, Form 1A, Page 1 of 15

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4. Which of the following complexes containing the ethylenediamine (en) ligand have an optical isomer? I [FeCl4(en)]2II cis-[FeCl2(en) 2]+ III trans-[FeCl2(en)2]+ A. B. C. D. E.

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I II III I , III II , III

5. How many unpaired electrons would you expect in the complex ion [Co(OH)6]4- , considering that the hydroxo ligand is a weak-field ligand? A. 0 B.

1

C. 2 D. 3 E.

____

4

6. The [Mn(NH3)6]2+ ion has five unpaired electrons. Which one of the following statements is incorrect concerning the complex ion: A. The complex is paramagnetic. B. The coordination number of the metal in the complex ion is six. C.

The ammine ligand is acting as a strong-field ligand in the complex.

D. The geometry of the complex is octahedral. E.

The crystal field splitting in the complex is relatively small, and will absorb photons of low energy in the visible.

Final Exam, CHE 132 Fall 2018, Form 1A, Page 2 of 15

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7. Which statement is usually true? A. As the temperature increases, the solubility of a gas increases. B.

As the temperature increases, the solubility of a solid in water decreases.

C. As the temperature decreases, the solubility of a gas increases. D. As the temperature decreases, the solubility of a solid in water stays the same. E.

____

Temperature does not affect solubility of gases, only solids.

8. The reaction NO2(g) + NO(g) ↔ N2O(g) + O2(g) has a standard Gibbs free energy of reaction ΔG0 1273 = -9.67 kJ mol-1 at 1273.15 K. The four species participating in the reaction are simultaneously injected in a container at that temperature so that their partial pressures are p0 (NO2 ) = 2.09 atm; p0 (NO) = 4.18 atm; p0 (N 2 O) = 1.57 atm; p0 (O 2 ) = 3.66 atm.

Which of the following statements is correct concerning the reaction system in the indicated conditions? A. ΔG1273 = -5.24 kJ mol-1 and the reaction proceeds so that the partial pressure of N2 O(g) increases.

B.

The reaction system is at equilibrium.

C.

ΔG1273 = -5.24 kJ mol-1 and the reaction proceeds so that the partial pressure of NO(g) increases.

D. ΔG1273 = -14.10 kJ mol-1 and the reaction proceeds spontaneously towards the products.

E.

ΔG1273 = -14.10 kJ mol-1 and the reaction proceeds spontaneously towards the reactants.

Final Exam, CHE 132 Fall 2018, Form 1A, Page 3 of 15

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9. Predict which way the reaction will shift if NO(g) is increased.

A. left B. C.

right neither, already at equilibrium

D. neither, equilibrium is not affected by concentration E.

____

not enough information

10. The equilibrium constant Kc is 1.28 x 104 at 852 K for the reaction below 2SO2 (g) + O 2 (g) ←⎯→ 2 SO3(g) For a 2.0-L flask containing 0.025 mol of SO2, 0.0010 mol of O2, and 1.2 mole of SO3, which statement is true? A. Q < K, equilibrium shifts to products B. Q < K, equilibrium shifts to reactants C.

Q > K, equilibrium shifts to reactants

D. Q > K, equilibrium shifts to products E.

____

Q = K, the reaction is at equilibrium

11. If you want to find the pH of a 0.100 M solution of HCOO- , which reaction would you write for the RICE table? A. H 3O + and OH- to make water B.

acid disssociation equation for HCOOreaction of HCOOH with water

C. D. base dissociation equation for HCOOH E.

reaction of HCOO- with water

Final Exam, CHE 132 Fall 2018, Form 1A, Page 4 of 15

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12. Trimethylammonium chloride ((CH3)3NH 3Cl) is a salt. When the salt is dissolved in water, it gives off a foul fishy smell. Is the smelly solution acidic, basic or neutral? A. acidic B. C.

basic neutral

D. not enough information E.

____

none of the above

13. For the amino acid aspartic acid (below) how many equivalents of OH- must be added in a titration curve to reach the 2nd pKa ?

A. 1 B. C.

1.5 2

D. 2.5 E.

____

3

14. Which of the following substances has the greatest molar solubility in water? A. BaCO3, Ksp=2.6 x 10-9 B. BaSO4, Ksp=1.1 x 10-10 C.

CaSO4, Ksp=4.9 x 10-5

D. Ca(OH)2, Ksp =5.5 x 10-5 E. Cu(OH)2, K sp=2.2 x 10-20

Final Exam, CHE 132 Fall 2018, Form 1A, Page 5 of 15

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15. For the solution below, what are the chemical formulas of the major species present at equilibrium? Do not include water. 0.20 mol of HI is added to 1.0 L of 1.0 M NH3 solution A. NH4+ , NH3 B. NH3, I- , H3O + C. NH3, H3O + D. NH4+ , I- , H3O + E. NH4+ , NH3, I-

____

16. Select the strongest reducing agent among the species listed. A. F B. C.

Cl Ca (s)

D. Mn(s) E.

I-

Final Exam, CHE 132 Fall 2018, Form 1A, Page 6 of 15

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17. In aqueous solution, the Ni2+ ion forms a complex with 4 CN- anions. What is the formation constant expression for the equilibrium between the hydrated metal ion and the aqueous complex?

1 /4 ÍÈÍÍ ÍÈ ˘ 2 − ˙˘˙ ÍÍÍ ÍÍÎ Ni(CN) 4 ˙˙˙˚ ˙˙˙˙ ˚ Î A. K f = 1 /4 È ˘ ˘ 1 /4 ÍÈÍ ÈÍ ˙ ÍÍ ÍÍ Ni(H O) ˘˙˙˙ 2 + ˙˙˙ ÍÍÍÍ CN − ˙˙˙˙ ÍÍ Î ˙˙ ÍÎ 2 4˚ ˙˚ Î ˚ ˘ ÍÈÍ ÍÈ ÍÍ ÍÍ Ni(CN) ˙˘˙˙ + ˙˙˙˙ ÍÍ Î ˚ ˙˙˚ Î B. K f = È ˘È ˘ ÍÍ ÈÍ ÍÍ ÍÍ Ni(H O)˘˙˙˙ 2 + ˙˙˙˙ ÍÍÍÍ CN − ˙˙˙˙ ÍÍ Î ˙˙ ÍÎ 2 ˚ ˙˚ Î ˚ ˘ ÍÈÍ ÈÍ ÍÍ ÍÍ Ni(CN) ˘˙˙˙ 2 − ˙˙˙˙ ÍÍ Î ˙˙ 4˚ Î ˚ K = C. f 4 È 2 + ÍÈÍ Ni(H O) ˙˘˙ ÍÍÍ CN − ˘˙˙˙˙ ÍÎ Í 2 4˙ ˙˚ ˚ ÍÎ

____

ÍÈÍÍ ÍÈ ˘ 2 + ˙˘˙ ÍÍÍ ÍÍÎ Ni(CN) 4 ˙˙˙˚ ˙˙˙˙ ˚ Î D. K f = ˘ 1 /4 ˘˙˙ 2 + ÍÈÍ ÈÍÍ −˙ ÍÎ Ni(H 2 O) 4 ˙˚ ÍÍÍÎ CN ˙˙˙˙ ˚ ˘ ÍÈÍ ÍÈ ÍÍ ÍÍ Ni(CN) ˙˘˙˙ 2 − ˙˙˙˙ ÍÈÍÍH O ˙˘˙˙ 4 ÍÍ Î ˙˙ Î 2 ˚ 4 ˚ Î ˚ E. K f = ˘4 ÈÍÍ ˘˙˙ 2 + ÍÈÍ −˙ ˙˙˙ Í CN Ni(H O) ˙ ÍÍ 2 4˚ ÎÍ ˙˚ Î

18. Determine the number of I- particles in the CuI unit cell.

A. 1 B.

2

C. 3 D. 4 E.

8

Final Exam, CHE 132 Fall 2018, Form 1A, Page 7 of 15

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19. The mechanism for the reaction between CH3OH (methanol) and HBr in aqueous solution is believed to involve two steps: CH3OH(aq) + H3O + (aq) ↔ CH3OH2+ (aq) + H2O(liq) CH3OH2+ (aq) + Br- (aq) → CH3Br(aq) + H2O(liq)

k1 , k- 1 , fast k2 , slow

Which one of the following statements is incorrect? A. The overall reaction is CH3OH(aq) + H3O + (aq) + Br- (aq) → CH3Br(aq) + 2 H2O(liq) B.

The rate law of the reaction is first order with respect to [CH3OH].

C.

The rate law of the reaction is first order with respect to [Br - ].

D. The rate constant of the mechanism is related to the rate constant of the individual elementary states according to k = k2 (k1/k-1)(1/2). E.

____

The species CH3OH 2+ (aq) is a reaction intermediate.

20. Consider the reaction Fe2O 3(s) + 2 Al(s) → 2 Fe(s) + Al2O 3(s) At 25 °C the standard enthalpy and the standard entropy of the reaction are, respectively ΔH 0rxn = -412.7 kJ mol-1 and ΔS0rxn = -375.2 J K- 1 mol- 1. To a resonable approximation ΔH 0rxn and ΔS0rxn may be assumed to be independent of the temperature. By also considering the dependence with temperature of ΔG 0rxn , determine which one of the following statements is incorrect for the reaction: A. The reaction is product-favored at high temperatures. B.

The reaction is exothermic.

C.

There is a special temperature at which the equilibrium constant of the reaction satisfies K=1.

D. The number of microstates of the products is smaller than the number of microstates of the reactants. E.

Under standard conditions the reaction is spontaneous at low temperatures.

Final Exam, CHE 132 Fall 2018, Form 1A, Page 8 of 15

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21. Consider the reaction 2 H2S(g) + 3 O2(g) → 2 H2O(liq) + 2 SO2(g) at 25 °C. Which one of the following statements is incorrect concerning the standard entropy of the reaction ∆S0rxn or the standard molar entropies S0 of the species in the reaction at the same temperature? A. S°(SO2,g) is positive. B. S°(H2O,liq) < S°(H2S,g) C.

S°(O2,g) = 0 D. ∆S0rxn is negative. E. S°(H2O,liq) < S°(SO2,g)

____

22. Given the following information at 25 °C: COCl2(g) + 4 NH3(g) → CO(NH2)2(s) + 2 NH4Cl(s)

ΔG 01 = -332.0 kJ mol-1

calculate the standard Gibbs free energy of the reaction (1/2) CO(NH2)2(s) + NH4Cl(s) → (1/2) COCl2(g) + 2 NH3(g) at the same temperature. A. 166.0 kJ mol-1 B. -664.0 kJ mol-1 C.

- 98.24 kJ mol-1

D. 332.0 kJ mol-1 E. -83.0 kJ mol-1

Final Exam, CHE 132 Fall 2018, Form 1A, Page 9 of 15

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23. Kinetic data at relatively short times for the reaction CO(g) + NO2(g) → CO2(g) + NO(g) at 120 °C are given in the table below: Experiment

[CO] (mol L-1)

[NO2] (mol L-1)

Initial rate (mol L-1 h-1)

1 2 3

5.0 × 10-4 5.0 × 10-4 1.0 × 10-3

0.36 × 10-4 0.18 × 10-4 0.36 × 10-4

3.4 × 10-8 1.7 × 10-8 6.8 × 10-8

Which on of the following expressions is the rate law for the reaction at short times in the specified conditions. A. B. C. D. E.

____

rate = k [CO]-1 [NO2]-1 rate = k [CO]-1/2 [NO2] rate = k [CO] [NO2] rate = k [CO] [NO2]2 rate = k [CO] [NO2]1/2

24. In the following electrochemical cell, Au(s) |Au3+(aq) || Cu 2+(aq) | Cu(s) ΔG° (kJ/mol) is A. 673,000 B. C.

- 224 - 337

D. 673 E.

- 673,000

Final Exam, CHE 132 Fall 2018, Form 1A, Page 10 of 15

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25. At 25 °C the standard enthalpy of the reaction CS2(liq) + 3 O2(g) → CO2(g) + 2 SO2(g) is -1103.9 kJ mol-1. At the same temperature the standard enthalpies of formation of CO2(g) and SO2(g) are, respectively, -393.509 kJ mol-1 and -296.84 kJ mol-1. What is the standard enthalpy of formation of CS2(liq) at 25 °C? A. -276.8 kJ mol-1 B. -92.3 kJ mol-1 C.

116.7 kJ mol-1

D. 1304.1 kJ mol-1 E. -200.2 kJ mol-1

____

26. Consider a solution of 0.70 M aniline. What is the pOH?

A. 0.15 B.

4.78

C.

5.23

D. 9.22 E. 9.40

____

27. What is pH of a solution with [OH- ] = 1.0 x 10-9 M

A. 9.00 B.

- 9.00

C. 0.900 D. 5.00 E.

none of the above

Final Exam, CHE 132 Fall 2018, Form 1A, Page 11 of 15

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28. Consider a 1.00 M solution of HClO. What is the pH of the aqueous solution?

A. 0.10 B. 3.77 C.

3.82

D. 7.63 E. 10.18

____

29. A 20.0-mL sample of 0.20 M HCl is titrated with 0.10 M NaOH. What is the pH of the solution after 15.0 mL of NaOH has been added to the acid?

A. 0.70 B.

1.15

C.

2.40

D. 2.60 E. 7.00

____

30. A student places 100.0 mL of 0.500 M CH3COOH in a 250 mL erlenmeyer flask and adds indicator. She then adds 15.00 mL of 1.003 M standardized NaOH. What is the initial [CH3COOH] used in the RICE table to calculate pH of the solution?

A. 0.500 M B. 0.566 M C.

0.0350 M

D. 0.304 M E.

0.350 M

Final Exam, CHE 132 Fall 2018, Form 1A, Page 12 of 15

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31. At a certain temperature the vapor pressure of pure chloroform (CHCl3) is measured to be 267 mm Hg. Suppose a solution is prepared by mixing 54.7 g of chloroform and 69.6 g of acetyl bromide (CH3COBr). Calculate the partial pressure of chloroform vapor above this solution. You may assume the solution is ideal. Molar mass CHCl3 = 119.3779 g/mol Molar mass CH3COBr = 122.9487 g/mol A. 117 mm Hg B.

119 mm Hg

C. 122 mm Hg D. 148 mm Hg E.

____

267 mm Hg

32. Rank order the freezing points of the following solutions (lowest to highest): I. II. III. IV.

3.2 g of 1,3-pentanediol (C5H 12O 2) dissolved in 100.0 mL of water 3.2 g of MgCl2 dissolved in 100.0 mL of water 3.2 g of HA dissolved in 100.0 mL of water 100.0 mL of pure water

Molar mass C5H 12O 2 = 104.148 g/mol Molar mass MgCl2 = 95.211 g /mol Molar mass HA = 100.0 g/mol A. I, II, III, IV B. C.

I, III, II, IV II, III, I, IV

D. IV, II, III, I E.

IV, I, II, III

Final Exam, CHE 132 Fall 2018, Form 1A, Page 13 of 15

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33. Calculate Kc at 723 K for the reaction below given that at that temperature, Kp = 2.22 x10 4. Assume that the pressure is given in atm.

2 NH3(g)

⇔

N2(g) + 3 H2(g)

A. 6.2 x 10-4 B.

0.16

C. 6.3 D. 374 E. 7.81 x 107

____

34. The decomposition of SO2Cl2 is a first order elementary reaction SO2Cl2(g) → SO 2(g) + Cl2(g) At 600 K the rate constant for the reaction is 2.8 × 10-3 min-1. If the initial concentration of SO2Cl2 is 1.24 × 10-3 mol L-1, how long will it take for the concentration of the reactant to drop to 0.31 × 10-3 mol L-1? A. B. C. D. E.

248 min 495 min 179 min 357 min 215 min

Final Exam, CHE 132 Fall 2018, Form 1A, Page 14 of 15

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35. The decomposition of nitrogen dioxide NO2(g) → NO(g) + (1/2) O2(g) at high temperature follows the rate law rate = k [NO2]2 It takes 1.76 min for the concentration of NO2(g) to fall from 0.250 mol L-1 to 0.100 mol L-1. What is the value of the rate constant for the reaction? A. 0.568 L mol-1 min-1 B. 0.0852 L mol-1 min-1 C. 0.521 L mol-1 min-1 D. 7. 537 L mol-1 min-1 E. 3.41 L mol-1 min-1

____

36. When heated to a high temperature cyclobutane, C4H 8, decomposes to ethylene: C4H 8(g) → 2 C2H 4(g) The activation energy for the reaction is Ea = 260 kJ mol-1 and the rate constant of the reaction at 800 K is k = 0.0315 s-1. What is the value of the rate constant of the reaction at 850 K? A. 0.0317 s-1 B. 0.0449 s-1 C. 0.751 s-1 D. 0.314 s-1 E. 3.26 × 10-6 s-1

Final Exam, CHE 132 Fall 2018, Form 1A, Page 15 of 15

ID: A

Final Exam CHE 132 Fall 2018 Answer Section

Form 1A

MULTIPLE CHOICE 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34.

ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS: ANS:

E D B B D C C D A C E A B D E C C D D A C A C D C B D B B D B C C B

PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS: PTS:

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1

Final Exam, CHE 132 Fall 2018, Form 1A, Page 1 of 15

ID: A 35. ANS: E 36. ANS: D

PTS: PTS:

1 1

Final Exam, CHE 132 Fall 2018, Form 1A, Page 2 of 15...