1. Which of the intermolecular forces is most closely related to molar mass?

A. ion-ion

B. ion-dipole

C. dipole-dipole

D. hydrogen bonding

E. dispersion forces

2. The molecules in liquid butane (C₃H₈) are attracted to each other by which of the

following intermolecular forces:

A. dipole-dipole

B. hydrogen bonding

C. dispersion forces

D. Both A and C

E. A, B, and C

3. Which of the following has the highest boiling point?

A. O₂ B. Ar C. He D. HF E. HCl

4. Which of the following would have the highest vapor pressure at room temperature?

A. C₂H₂ B. C₂H₆ C. C₃H₆ D. C₆H₆ E. C₇H₁₆

5. If a substance has a low boiling point, it most likely has

A. a low heat of vaporization

B. a low vapor pressure

C. both of these

6. The boiling point of flourine gas should be about the same as

A. He B. Ne C. Ar D. Kr E. Xe

7. The temperature at which the vapor pressure of a liquid equals the external pressure is

called the:

A. boiling point

B. critical point

C. melting point

D. sublimation point

E. flash point

8. The enthalpy of condensation is equal to but opposite in sign from, the enthalpy of:

A. crystallization

B. formation

C. fusion

D. sublimation

E. vaporization

For Questions 9 through 12, use the following diagram:

9. Estimate the normal boiling point of the substance represented above.

A. 18 °C B. 22 °C C. 30 °C D. 38 °C E. 44 °C

10. If the solid above is heated at 200 mmHg, it will

A. melt at 20 ° C

B. melt below 20 °C

C. sublime at 20 °C

D. sublime below 20 °C

E. liquefy at 20 °C

11. If the pressure on the liquid above is reduced to 600 mmHg its new boiling point will be

about

A. 15 °C B. 20 °C C. 30 °C D. 35 °C E. 40 °C

12. Which substance has weaker intermolecular forces, this substance or water?

A. This substance B. Water C. Cannot be estimated with the above information

13. How many joules of heat would be required to transform 20.0 g of "ice" at 0°C to liquid

water at 20°C?

A. 840 J

B. 1700 J

C. 6700 J

D. 7500 J

E. 8400 J

14. Which of the following is true concerning "colligative properties"?

A. Addition of solute raises the boiling point of a solvent.

B. An ionic solute will have a greater effect on the boiling point than a nonionic solute will.

C. Addition of solute raises the vapor pressure of a solvent.

D. A and B

E. A, B, and C

15. Calculate the freezing point of a solution prepared by dissolving 8.9 g of MgCl₂ in

98 g of water.

A. -3.5 °C

B. -5.3 °C

C. -0.51 °C

D. -1.9 °C

E. -0.33 °C

16. Which of the following aqueous solutions would have the lowest boiling point?

A. 0.1 m CaCl₂

B. 0.1 m KNO₃

C. 0.1 m HCl

D. 0.1 m C₆H₁₂O₆

E. all would have the same boiling point

17. Determine the osmotic pressure of a solution that is prepared by dissolving 0.014 moles of

NaNO₃ in enough water to make 500. mL of solution at 25 °C .

A. 1.37 atm

B. 0.685 atm

C. 0.0729 atm

D. 0.0364 atm

E. 2.06 atm

18. The freezing point of a solution prepared by dissolving 3.00 g of compound X

(a nonelectrolyte) in 100 g of water is -0.279°C. The molar mass of compound X is:

A. 100 g/mol

B. 200 g/mol

C. 300 g/mol

D. 175 g/mol

E. 95.0 g/mol

19. An unknown substance, Camellium, is found to be soluble in hexane (C₆H₁₄) but not in

water. Camellium is most likely

A. polar

B. ionic

C. nonpolar

D. either A or B, but definitely not C

20. A solid sample is at its normal melting point. Small additions of heat at this point will cause the solid to

A. change from solid to liquid

B. change from solid to gas

C. decrease in temperature

D. increase in temperature

E. no change of any type will occur

21. Consider the following solutions separated by a semipermeable membrane:

Solution A 1.85 M NaCl (aq)

Solution B 5.00 M NaCl (aq)

Which of the following is a true statement concerning the system above?

A. Water flows from A to B

B. Water flows from B to A

C. Ions flow from B to A

D. Statements A and C are true

E. Statements B and C are true

22. What is the equilibrium constant expression for the following reaction?

2N₂O (g) + N₂H₄ (g) 3N₂ (g) + 2H2O (l)

A. B. C.

D. E.

23. In which of the following reactions is the "formation of products" least favored?

A. 2 H₂ (g) + O₂ (g) 2 H₂O (g) K = 1.7 x 10²⁷

B. N₂ (g) + O₂ (g) 2 NO (g) K = 5.0 x 10^-31

C. H₂ (g) + Cl₂ (g) 2 HCl (g) K = 3.2 x 10¹⁶

D. 2 HF (g) H₂ (g) + F2 (g) K = 1.0 x 10^-13

E. 2 NOCl (g) 2NO₂ (g) + Cl₂ (g) K = 4.7 x 10^-4

24. Given the following equilibria

2 H₂ (g) + O₂ (g) 2 H₂O (g) K₁ = 1.7 x 10²⁷

H₂ (g) + Cl₂ (g) 2 HCl (g) K₂ = 3.2 x 10¹⁶

Calculate K for

2 H₂O (g) + 2 Cl₂ (g) 2 HCl (g) + O₂ (g).

A. 1.7 x 10^-6

B. 1.7 x 10⁶⁰

C. 3.8 x 10^-11

D. 2.7 x 10¹⁰

E. 6.0 x 10⁵

25. For the following equilibrium:

H₂ (g) + Br₂ (g) 2 HBr (g) K = ?

If an equilibrium mixture of the gases above consist of 0.125 M H₂ (g), 0.208 M Br₂ (g),

and 0.115 M HBr (g), calculate the value of K for this reaction.

A. 2.0

B. 4.4

C. 2.3 x 10^-1

D. 5.1 x 10^-1

E. 3.0 x 10^-3

26. Consider the following reaction:

2 H2O(g) + 2 Cl2 (g) 4 HCl (g) + O2 (g) DH = - 28 kJ

Which of the following will cause the reaction to shift to the right?

A. removing Cl2 (g)

B. increasing the temperature

C. adding O₂ (g)

D. all of these

E. none of these

27. "When a stress is applied to a system which is in equilibrium, it will shift to reestablish

equilibrium" is one way of stating:

A. Clausius-Clapeyron's Rule

B. Le Chatelier's Principle

C. The First Law of Thermodynamics

D. The Equilibrium Hypothesis

E. Bryan's Principle