# Chem II Chapter 13

12 Questions | Total Attempts: 180  Settings  This quiz is to review for the Chapter 13 test.

• 1.
What increases when 2 pure substances are mixed to form a solution?
• A.

Heat

• B.

Entropy

• C.

Solubilty

• D.

Nothing increases

• 2.
What is the molality of a solution of 50 g of CH3CH2CH2OH in 152 mL water, if the density of water is 1 g/mL?
• A.

5.47 m

• B.

0.00547 m

• C.

0.833m

• D.

0.183m

• 3.
A 2.300 molal solution of KCl is prepared. How many grams of KCl are present in a sample containing 5.0 kg of water?
• A.

546.7 g

• B.

856.8 g

• C.

113.7g

• D.

74.5g

• 4.
The solubility of oxygen gas in water is 0.590 g/L at a pressure of 15 atm. What is the Henry's law constant for oxygen gas in units of L-atm/mol?
• A.

0.00393

• B.

0.00123

• C.

814

• D.

1.26

• 5.
At a given temperature, you have a mixture of benzene (vapor pressure of pure benzene = 745 torr) and toluene(vapor pressure of pure toluene = 290 torr). The mole fraction of benzene in solution is 0.59. Assuming ideal behavior, calculate the mole fraction of toluene in the vapor above the solution.
• A.

0.123

• B.

0.778

• C.

0.641

• D.

0.359

• 6.
150g of NaCl dissolves in 1 kg of water at 25oC. the vapor pressure of pure water at this temperature is 23.8 torr. Determine the vapore pressure of the solution.
• A.

21.8 torr

• B.

22.5 torr

• C.

20.6 torr

• D.

19.7 torr

• 7.
A solution if prepared from 31.4g of a nonvolatile, nondissociating solute and 85g of water. The vapor pressure of the solution at 60oC is 142 torr. The vapor pressure of water at 60oC is 150 torr. What is the molar mass of the solute?
• A.

92 g/mol

• B.

215 g/mol

• C.

118 g/mol

• D.

314 g/mol

• 8.
Colligative properties depend on ..
• A.

The chemical properties of the solute

• B.

The chemical properties of the solvent

• C.

The masses of the individual ions

• D.

The number of particles dissolved

• 9.
Raoult's law relates the vapor pressure of the solvent above the soltion to its mole fraction in the solutio. Which of the following is an accurate statement?
• A.

Raoult's law applies exactly to all solutions

• B.

Raoult's law works best when applied to concentrated solutions

• C.

Roaults law works best when applied to dilute solutions

• D.

Raoult's law applies only to non-ideal solutions

• 10.
The Tyndall effect..
• A.

Is observed in concentrated solutions

• B.

Is obsreved only in dilute solultions

• C.

Is observed in colloidal dispersions

• D.

Is caused by Brownian motion

• 11.
When a 20 g sample of an unknown compound is dissolved in 500g of benzene, the freeezing point of the resulting solution is 3.77oC. The freezing point of pure benzene is 5.48oC and the K value for benzene is 5.12. Calcualte the molar mass of the unknown
• A.

160 g/mol

• B.

80 g/mol

• C.

120 g/mol

• D.

140 g/mol

• 12.
Calculate the molarity of a solution contians KCl and water whose osmotic pressure at 21oC is 100 torr.
• A.

0.005 M

• B.

0.01 M

• C.

0.08 M

• D.

0.0025 M

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