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Unit 2. States of Matter
III. Solutions
Quiz 1

1.A solution of chloroform, CHCl3, in carbon tetrachloride, CCl4, is nearly ideal. The vapor pressure of chloroform is 170 mm Hg at 20 °C, and the vapor pressure of carbon tetrachloride is 87 mm Hg at this temperature. What is the mole fraction of carbon tetrachloride in the vapor over an equimolar solution of these two liquids?
0.25
0.87
0.66
0.50
0.34
2.To prepare 10.0 liters of a 0.20-molar KNO3 solution (molecular weight 101) a student should follow which of the following procedures?
The student should weigh 202 grams of solute and add sufficient water to obtain a final volume of 10.0 liters.
The student should weigh 202 grams of solute and add 10.0 liters of water.
The student should weigh 20.2 grams of solute and add 10.0 kilograms of water.
The student should weigh 20.2 grams of solute and add 10.0 liters of water.
The student should weigh 20.2 grams of solute and add sufficient water to obtain a final volume of 10.0 liters.
3.A 5.2 molal aqueous solution of methyl alcohol, CH3OH, is given to a student. What is the mole fraction of methyl alcohol in this solution?
0.10
0.19
0.086
0.050
0.094
4.Choose the aqueous solution with the highest boiling point.
0.10 M NaNO3
0.10 M HCl
0.10 M LiBr
0.10 M CaCl2
0.20 M CH2O
5.I. The molal freezing point constant, Kf, of the solvent
II. The freezing point of the pure solvent and the freezing point of the solution

When using the freezing point depression method of determining the molar mass of a nonelectrolyte, what additional information is needed?

the mass of the solute
the volume of the solvent and the mass of the solute
the mass of the solvent and the boiling point of the solvent
the mass of the solvent and the mass of the solute
no additional information is needed
6.A solution is 10 percent urea by mass. Which item(s) from the following list are needed to calculate the molarity of this solution?

I. The density of the solution
II. The density of the solvent
III. The molecular weight of urea

I and III
I only
II only
III only
I and II
7.Which of the following aqueous solutions would freeze at the lowest temperature?
0.30 m C2H5OH
0.30 m NH4Br
0.30 m Cu(C2H3O2) 2
0.30 m LiI
0.30 m K3PO4
8.Which of the following aqueous solutions would have the greatest conductivity?
0.28 M Na3PO4
0.28 M AgNO3
0.28 M KMnO4
0.28 M KOH
0.28 M HBr
9.Pick the pair of substances that will most likely obey Raoult's law.
CH3CH2CH2CH2OH(l) and H2O(l)
CH3CH2CH2CH2OH(l) and C7H16 (l)
C7H16 (l) and C8H18 (l)
H3PO4 (l) and H2O(l)
C8H18 (l) and H2O(l)
10.Pick the conditions that would yield the highest concentration of NH3(g) in water.
Partial pressure of gas = 0.75 atm; Temperature of water = 50°C
Partial pressure of gas = 1.0 atm; Temperature of water = 25°C
Partial pressure of gas = 2.0 atm; Temperature of water = 75°C
Partial pressure of gas = 1.0 atm; Temperature of water = 75°C
Partial pressure of gas = 2.0 atm; Temperature of water = 25°C