Prince George’s Community College

CHM1010QUIZ 5C-CHAPTER 12

Multiple Choice Questions

1)Choose the statement below that is TRUE.

A) A solution will form between two substances if the solute-solvent interactions are of comparable strength to the solute-solute and solvent-solvent interactions.

B) A solution will form between two substances if the solute-solvent interactions are small enough to be overcome by the solute-solute and solvent-solvent interactions.

C) A solution will form between two substances if the solute-solute interactions are strong enough to overcome the solvent-solvent interactions.

D) A solution will form between two substances only if the solvent-solvent interactions are weak enough to overcome the solute-solvent interactions.

E) None of the above are true.

Answer: A

2)Give the major force between ethanol and water.

A) dipole-dipole

B) dispersion

C) hydrogen bonding

D) ion-ion

E) ion-dipole

Answer: C

3)Give the major force between acetone and chloroform.

A) dipole-dipole

B) dispersion

C) hydrogen bonding

D) ion-ion

E) ion-dipole

Answer: A

4)Choose the situation below that would result in a ΔHsolution near 0.

A) When |ΔHsolvent||ΔHsolute|

B) When |ΔHsolute||ΔHhydration|

C) When |ΔHsolute| < |ΔHhydration|

D) When |ΔHsolute| is close to |ΔHhydration|

E) There isn't enough information to determine.

Answer: D

8) Choose the situation below that would result in an exothermic ΔHsolution.

A) When |ΔHsolute||ΔHhydration|

B) When |ΔHsolute| is close to |ΔHhydration|

C) When |ΔHsolute||ΔHhydration|

D) When |ΔHsolvent||ΔHsolute|

E) There isn't enough information to determine.

Answer: C

9) Choose the situation below that would result in an endothermic ΔHsolution.

A) When |ΔHsolute||ΔHhydration|

B) When |ΔHsolute| < |ΔHhydration|

C) When |ΔHsolute| is close to |ΔHhydration|

D) When |ΔHsolvent||ΔHsolute|

E) There isn't enough information to determine.

Answer: A

10) Calculate the boiling point of a solution of 500.0 g of ethylene glycol (C2H6O2) dissolved in 500.0 g of water. Kf = 1.86°C/m and Kb = 0.512°C/m. Use 100°C as the boiling point of water.

A) 108°CB) 92°CC) 130°CD) 70°CE) 8.3°C

Answer: A

11) The boiling point elevation of an aqueous sucrose solution is

found to be 0.39°C. What mass of sucrose (molar mass=

342.30 g/mol) would be needed to dissolve in 500.0 g of

water? Kb (water) = 0.512°C/m.

A) 261 g sucroseB) 528 g sucroseC) 762 g sucroseD) 223 g

Sucrose E) 130. g sucrose

Answer: E

12) Determine the boiling point of a solution that contains 78.8 g of

naphthalene (C10H8, molar mass = 128.16 g/mol) dissolved in 722

mL of benzene (d = 0.877 g/mL). Pure benzene has a boiling point of

80.1°C and a boiling point elevation constant of 2.53°C/m.

A) 2.2°CB) 2.5°CC) 82.3°CD) 80.4°CE) 82.6°C

Answer: E

13) Give the reason that antifreeze is added to a car radiator.

A) The freezing point is lowered and the boiling point is elevated.

B) The freezing point is elevated and the boiling point is lowered.

C) The freezing point and the boiling point are elevated.

D) The freezing point and the boiling point are lowered.

E) None of the above.

Answer: A

14) Place the following aqueous solutions of nonvolatile, nonionic compounds in order of decreasing osmotic pressure.

I. 0.011 M sucrose II. 0.00095 M glucoseIII. 0.0060 M glycerin

A) I > III > II

B) I > II > III

C) II > III > I

D) III > I > II

E) II > I > III

Answer: A

15) Place the following solutions in order of increasing osmotic pressure.

I. 0.15 M C2H6O2II. 0.15 M MgCl2III. 0.15 M NaCl

A) III < I < II

B) II < III < I

C) I < II < III

D) II < I < III

E) I < III < II

Answer: E

16) A compound is found to have a molar mass of 598 g/mol. If 35.8 mg

of the compound is dissolved in enough water to make 175 mL of

solution at 25°C, what is the osmotic pressure of he resulting solution?

A) 3.42 torrB) 6.36 torrC) 5.01 torrD) 5.99 torr

E) 8.36 torr

Answer: B

17) A 150.0 mL sample of an aqueous solution at 25°C contains 15.2 mg

of an unknown nonelectrolyte compound. If the solution has an

osmotic pressure of 8.44 torr, what is the molar mass of the unknown

compound?

A) 223 g/molB) 294 g/molC) 341 g/mol

D) 448 g/molE) 195 g/mol

Answer: A

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