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Timothy SubrahmanyamSpring 2017 – Study Union

Study Union Spring 2017

Live Streamed Final Exam Review for Chemistry II (CHM 2046)

Tuesday, April 25th, 2017

9AM – 11AM

By Timothy Subrahmanyam

This review document is on https://ucfstudyunion.wordpress.com/chemistry-2/

A video of this review can be found by searching SARC UCF youtube

Chapter 11: Liquids, Solids, and Intermolecular Forces

https://ucfstudyunion.wordpress.com/chemistry-2/


1. Choose the substance with the highest boiling point.A) CH3CH2CH2CH3

B) CCl4

C) CH3OHD) CH3ClE) CF4

Figure 11.1

2. Calculate the mass of water that can be vaporized with 155 kJ of heat at 100 °C? (∆Hvap = 40.7 kJ/mol, Molar Mass of Water = 18.02 g/mol)

A) 12.0 gB) 35.9 gC) 36.7 gD) 68.6 gE) 88.9 g


(Use the diagram above to answer problems 3-4)

3. What is this substance at 30 °C and 1.0 atm?A) supercritical fluidB) crystalC) liquidD) solidE) gas

4. What does line segment AD represent?A) critical pointB) vaporization curveC) sublimation curveD) supercritical fluidE) fusion curve

Figure 11.2


5. How much heat in kJ is needed to raise the temperature of a 12.0 g benzene sample from -10.0 °C to 25.0 °C? (Molar mass of benzene = 78.11 g/mol, Specific Heat of Solid = 1.25 J/g x °C, Specific Heat of Liquid = 1.70 J/g x °C, Heat of Fusion = 9.8 kJ/mol, Melting Point = 5.5 °C, Boiling Point = 30.0 °C)

A) 0.5 kJB) 2.1 kJC) 17.2 kJD) 24.4 kJE) 60.2 kJ

Chapter 13: Solutions

6. Which one of the following substances is more likely to dissolve in CBr4?A) CH3CH2CH2OHB) NaFC) HBrD) CF4

E) HF

7. The solubility of carbon dioxide gas as 25 °C and 1 atm is 6.8 x 10-4 mol/L. If the partial pressure of carbon dioxide gas in air is 0.76 atm, what is the concentration (molarity) of dissolved carbon dioxide?

A) 1.4 x 10-5 MB) 2.9 x 10-4 MC) 4.5 x 10-4 MD) 5.2 x 10-4 ME) 7.1 x 10-4 M

8. Calculate the molality of a solution made by dissolving 34.0 g of NH3 in 2.00 x 103 g of solution. (Molar Mass of NH3 = 17.04 g/mol)

A) 1.02 m NH3

B) 0.53 m NH3

C) 12.43 m NH3

D) 12.53 m NH3

E) 4.65 m NH3


Figure 12.1

9. A 1.26 m aqueous solution of compound Y had a boiling point of 101.3 °C. Which one of the following could be compound Y? The boiling point elevation constant for water is 0.51 °C/m. A) Na3PO4

B) CaBr2

C) CH3CH2CH2OHD) NaClE) C6H12O6

10. What is the molar mass of lysozyme if 0.0750 g per 100.0 mL gives an osmotic pressure of 1.32 x 10-3 atm at 25 °C?

A) 0.11 x 103 g/molB) 0.58 x 103 g/molC) 1.13 x 103 g/molD) 1.24 x 104 g/molE) 1.39 x 104 g/mol


Figure 12.2

Chapter 14: Chemical Kinetics

11. For the reaction given, the NOBr changes from 1.000 M to 0.868 M in the first 10 seconds. Calculate the average rate in the first 10 seconds.

2 NOBr(g) 2 NO(g) + Br2(l) A) 0.0132 M/sB) 0.0066 M/sC) 0.0396 M/sD) 0.119 M/sE) 0.00147 M/s

12. Determine the rate law for the reaction 2NO2(g) + 2CO(g) 2NO(g) + 2CO2(g) given the data below.

A) Rate = k[NO2]2[CO]2

B) Rate = k[NO2]2

C) Rate = k[NO][CO2]D) Rate = k[NO2]2[CO]2[NO]2[CO2]2

E) Rate = k[NO2][CO]


13. The reaction below is first order with a rate constant of 2.90 x 10-4s-1 at a given set of conditions. Find the [SO2Cl2] at 865 s when [SO2Cl2]initial = 0.0225 M.

SO2Cl2(g) SO2(g) + Cl2(g)

A) 4.04 MB) 0.251 MC) 0.0225 MD) 0.0290 ME) 0.0175 M

14. The rate law for a reaction is

Rate = k[A]2[B]

Which one of the following statements is false?

A) The reaction is first order in B.B) K is the reaction rate constant.C) The reaction is second order in A.D) If [A] is doubled, the reaction rate will increase by a factor of 4.E) The reaction is second order overall.

15. Determine the overall reaction, the rate determining step, the rate law, and identify all catalysts and intermediates of the following mechanism.

1. 2HQ2R2 + 2R− ↔ 2Q2R2− + 2HR Slow

2. 2Q2R2− ↔ 2Q2R + 2R− Fast

Figure 13.1


Chapter 15: Chemical Equilibrium

16. The Keq for the equilibrium below is 0.002 at 450.0 °C. [T2 Q16]

CO2(g) + ½ O2(g) ↔ CO3(g)

What is the value of Keq at this temperature for the following reaction and does it favor reactants or products?

2 CO3(g) ↔ 2 CO2(g) + O2(g)

A) 2.50 x 102, productsB) 1.00 x 103, productsC) 1.00 x 103, reactantsD) 2.50 x 105, productsE) 2.50 x 105, reactants

17. For the reaction N2O4(g) ↔ 2 NO2(g) the value of Kc = 1.07 x 10-5. If the initial concentrations of N2O4 is 0.0125 M, what will be the equilibrium concentration of [NO2]?

A) 3.66 x 10-4 MB) 4.75 x 10-4 MC) 1.83 x 10-4 MD) 0.0123 ME) 0.0248 M

18. What is the equilibrium constant expression for the reaction?Cr(s) + 2 Br2(g) ↔ CrBr4(l)

A) [Br2 (g ) ]−2

B)[CrBr4 (l ) ][Br2 (g ) ]2

C) [Cr (s ) ] [Br2 (g ) ]2

CrBr4(l)


D)[CrBr4 (l ) ]

[Cr (s ) ] [Br2 (g ) ]

E)[CrBr 4 (l ) ]

[Cr (s ) ] [Br2 (g ) ]2

19. The reaction below with H° = −238 kJ is at equilibrium. Which of the following statements is false? 2 CH4(g) + 4 O2(g) 2 CO2(g) + 4 H2O(l)

A) Adding CH4(g) will shift equilibrium to the right.B) Cooling the container will shift equilibrium to the right.C) Adding a catalyst to the mixture has no effect.D) Adding helium to the container has no effectE) Removing O2(g) from the container shifts equilibrium to the left.F) Adding H2O(l) shifts equilibrium to the left.

20. The reaction below with H° = 83 kJ is at equilibrium. Which of the following statements is false?

2 SO2(g) + O2(g) 2 SO3(g)

A) Compressing the gases shifts equilibrium to the right.B) Heating the mixture shifts equilibrium to the right.C) Cooling the mixture shifts equilibrium to the left.D) Doubling the volume of the container shifts equilibrium to the right.E) Adding SO3(g) shifts equilibrium to the left.

Chapter 16: Acids and Bases

21. An aqueous solution of which of the following will form acidic solutions?

SrCl2 AlBr3 CH3NH3NO3 NaCHO2 NH4F

A) SrCl2, AlBr3

B) SrCl2 onlyC) AlBr3, CH3NH3NO3, NH4FD) NaCHO2 only


E) SrCl2, AlBr3, NaCHO2

22. Identify the Brønsted–Lowry acid, base, conjugate acid, and conjugate base in the following reaction.

HSO4−

(aq) + HCO3−

(aq) SO42−

(aq) + H2CO3(aq)

23. What is the conjugate base of the H2PO41-?

A) PO43-

B) HPO42-

C) H2PO41-

D) H3PO4

E) H4PO41+

24. Find the pH of 0.200 M HNO2(aq) solution at 25 °C with a Ka for HNO2 = 4.6 x 10-4.A) 1.03B) 2.02C) 7.00D) 8.23E) 9.27

Figure 15.1


Chapter 17: Aqueous Ionic Equilibrium

25. What is the pH of a buffer that is 0.050 M HC7H5O2 and 0.150 M NaC7H5O2?

Ka for HC7H5O2 = 6.5 x 10−5

A) 4.66B) 4.19C) 5.67D) 8.94E) 11.5

26. What is the pH of a buffer that has 0.140 moles HF (pKa = 3.15) and 0.071 moles KF in 1.00 L of solution when 0.020 moles of HCl is added?A) 1.20B) 2.65C) 3.00D) 3.15E) 4.16

27. Which of the solutions below has the greatest buffering capacity?A) 0.887 M NH4Cl and 0.234 M NH3

B) 0.812 M NH4Cl and 0.798 M NH3

C) 0.543 M NH4Cl and 0.492 M NH3

D) 0.194 M NH4Cl and 0.186 M NH3

E) 0.634 M NH4Cl and 0.267 M NH3


28. Calculate the pH of the solution that results when 100.0 mL of 0.15 M NaOH is added to 50.0 mL of 0.25 M HNO3.A) 1.17B) 5.88C) 1.77D) 1.83E) 12.23

29. Calculate the molar solubility of CaF2 in 0.100 M NaF at 25 C. Ksp of CaF2 = 1.46 x 10-10

A) 4.36 x 10-8

B) 1.46 x 10-8

C) 0.100D) 1.46 x 10-10

E) 5.34 x 10-10

Chapter 18: Free Energy and Thermodynamics

30. Calculate the entropy change of the surroundings at 25C for the reaction below. C3H8(g) + 5 O2(g) 3 CO2(g) + 4 H2O(g) ∆Hrxn = −2044 kJA) 1.30 kJ/KB) 15.5 kJ/KC) 6.86 kJ/KD) 10.4 kJ/KE) 20.5 kJ/K

31. The reaction CCl4(g) C(s, graphite) + 2 Cl2(g) has ∆H = +95.7 kJ and ∆S = +142.2 J/K at 25 °C. Calculate ∆G and determine if it is spontaneous.A) 5.33 x 104 J, spontaneous


B) 5.33 x 104 J, nonspontaneousC) -4.23 x 104 J, spontaneousD) -4.23 x 104 J, nonspontaneousE) 1.38 x 105 J, spontaneous

32. Determine the free energy change in the following reaction at 298 K. 2 H2O(g) + O2(g) 2 H2O2(g)

A) -333.6 kJB) -587.0 kJC) -668.4 kJD) 246.0 kJE) 123.6 kJ

33. Determine the free energy change in the following reaction at 298 K 2 H2O(g) + O2(g) 2 H2O2(g)

A) 246.0 kJB) -668.4 kJC) -562.8 kJD) -211.2 kJE) 667.2 kJ

Chapter 19: Electrochemistry

34. Balance the following equation in acidic solution and determine which element was oxidized and reduced, and determine the oxidizing and reducing agent.

I– + CrO42− → Cr3+ + I2

Substance

∆G , kJ/mol

H2O2(g) −105.6

O2(g) 0

H2O(g) −228.6

Substance ∆G , kJ/mol

H2 (g) + O2(g) H2O2(g) −105.6

2 H2 (g) + O2(g) 2 H2O(g) −457.2


35. Which of the following set of values are characteristic of a spontaneous reaction?A) ∆G° > 0, E° > 0, K > 1B) ∆G° < 0, E° < 0, K < 1C) ∆G° < 0, E° < 0, K > 1D) ∆G° > 0, E° > 0, K < 1E) ∆G° < 0, E° > 0, K > 1

36. Calculate the E°cell for the following for the overall reaction at 25 °C. IO3

–(aq) + 6 H+(aq) + 5 I−(aq) → 3 I2(s) + 3 H2O(l)

2 I−(s) I2(aq) + 2 e− E°red = 0.54 v

IO3−

(aq) + 6 H+(aq) + 5 e− ½ I2(s) + 3 H2O(l) E°red = 1.20 v

A) 0.66B) 0.648C) 1.74D) -1.74E) -0.648

37. Calculate the mass of Au that can be plated in 25 min using 5.5 A for the half-reaction below. Au3+(aq) + 3 e− → Au(s) (MMAu = 196.97 g/mol)A) 0.21 g AuB) 0.67 g AuC) 5.6 g AuD) 6.4 g AuE) 8.1 g Au


38. Which of the following statements is false?A) Anode loses weight in electrolytic cell.B) Cathode is connected to the negative end of battery in an electrolytic cell.C) Anions are attracted to the anode.D) Electrons flow from cathode to anode.E) Reduction occurs at the cathode.

Chapter 20: Radioactivity and Nuclear Chemistry

39. Which mode of radioactive decay produces the change from U to Th?A) Electron CaptureB) Beta decayC) Alpha decayD) Positron EmissionE) Gamma Decay

Extra Questions:

40. Determine the pH at 25 °C of a solution that is a mixture of 0.045 M HCl and 0.15 M HF. (Chap 15)A) 1.50B) 1.23C) 1.35D) 4.56E) 5.83

41. Calculate the pH at 25 °C of a 0.0015 M Sr(OH)2 solution. (Chap 15)A) 7.01B) 7.46C) 8.90D) 11.48E) 13.87

42. Which of the following materials can be used to oxidize Cu without oxidizing Ag? (Chap 18)A) F−

Reduction Half-Reaction

F2(g) + 2e− 2 F−(aq)

IO3−(aq) + 6 H++ 5e− I2(s) + 3H2O(l)

Ag+(aq) + 1e− Ag(s)

I2(s) + 2e− 2 I−(aq)

Cu2+(aq) + 2e− Cu(s)

Cr3+(aq) + 1e− Cr2+(aq)

Mg2+(aq) + 2e− Mg(s)


B) I−

C) I2

D) Cr3+

E) Mg2+

43. Which of the following metals will dissolve in HC2H3O2(aq)? (Chap 18)A) Au, AgB) Ag, CrC) Cu, H2, AgA) Cu onlyB) Fe, Cr

44. Decide whether each of the following will bespontaneous as written or in the reverse direction. (Chap 18)

F2(g) + 2 I−(aq) I2(s) + 2 F−

(aq)

Mg(s) + 2 Ag+(aq) Mg2+

(aq) + 2 Ag(s)

Cu2+(aq) + 2 I−

(aq) I2(s) + Cu(s)

Cu2+(aq) + 2 Cr2+

(aq) Cu(s) + 2 Cr3+(aq)


Au3+(aq) + 3e− Au(s)



2H+(aq) + 2e− H2(g)

Fe3+(aq) + 3e− Fe(s)

Cr3+(aq) + 3e− Cr(s)



F2(g) + 2e− 2 F−(aq)

IO3−(aq) + 6 H++ 5e− I2(s) + 3H2O(l)


I2(s) + 2e− 2 I−(aq)


Cr3+(aq) + 1e− Cr2+(aq)



45. If you have a 1.35 mg sample of Pu–236, calculate the mass that will remain after 5.00 years. Half-life of Pu–236 is 2.86 years. (Chap 19)A) 0.242 mgB) 0.402 mgC) 0.693 mgD) 0.754 mgE) 1.36 mg

Answers to Problems:

1. C2. D3. C4. E5. B6. D7. D8. A9. D

10. E11. B12. B13. E14. E15. Overall: 2HQ2R2 ↔ 2Q2R +

2HR Slow is RDS Rate = k[HQ2R2]2[2R-]2

Catalyst: R-


Intermediate: Q2R2-

16. D17. A18. A19. F20. D21. C22. Acid: HSO4

-, Base: HCO3-

Conj. Acid: H2CO3, Conj. Base: SO4

2-

23. B24. B25. A26. B27. B28. E29. B30. C31. B32. D

33. A34. Balanced: 6 I- + 16 H+ + 2 CrO4

2- 3 I2 + 2 Cr3+ + 8 H2O Reduced: CrO4

2- Oxidized: I-

Ox. Agent: CrO42- Red. Agent:

I- 35. E36. A37. C38. D39. C40. C41. D42. C43. E44. Spontaneous

Spontaneous In reverse In reverse

45. B

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