Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
|
|
|
1.
|
To
prepare 1.000 kg of 5.5% by mass KCl(aq), one may dissolve a. | 994.5 g KCl in
5.5 g of water. | b. | 5.5 g KCl in 994.5 g of water. | c. | 5.5 g KCl in
1000.0 g of water. | d. | 55 g KCl in 945 g of water. | e. | 55.0 g KCl in
1000.0 g of water. | | |
|
|
|
2.
|
What
is the molality of 13.82% by mass sulfuric acid? The molar mass of H2SO4 is
98.08 g/mol. a. | 0.1409
m | b. | 1.409 m | c. | 1.635
m | d. | 13.55 m | e. | 15.73
m | | |
|
|
|
3.
|
What
is the mole fraction of MgCl2 in a solution that is 11.04% by mass MgCl2(aq)?
The molar mass of MgCl2 is 95.21 g/mol. a. | 0.02295 | b. | 0.02349 | c. | 0.1104 | d. | 0.1160 | e. | 1.303 | | |
|
|
|
4.
|
What
is the weight percent of ammonia in 3.33 m NH3(aq)? a. | 0.332% | b. | 5.37% | c. | 5.67% | d. | 6.01% | e. | 56.7% | | |
|
|
|
5.
|
A
solution is prepared by mixing 66.7 g H2O with 33.3 g HOCH2CH2OH
(ethylene glycol). What is the concentration of ethylene glycol in units of molality? The molar
masses of water and ethylene glycol are 18.02 g/mol and 62.07 g/mol, respectively. a. | 0.127
m | b. | 0.333 m | c. | 4.99
m | d. | 5.36 m | e. | 8.04
m | | |
|
|
|
6.
|
What
mass of Cu(NO3)2 must be added to 1.00 kg H2O to prepare 97 ppm
Cu2+(aq)? a. | 3.3 x
10-4 g | b. | 5.2 x
10-4
g | c. | 9.7 x
10-3
g | d. | 0.033
g | e. | 0.29
g | | |
|
|
|
7.
|
Which
of the following statements are CORRECT?
1. | Solubility is the concentration of solute in equilibrium with
undissolved solute in a saturated solution. | 2. | If two liquids mix to an appreciable extent to form a solution,
they are immiscible. | 3. | If two liquids mix completely in any proportion to form a
solution, the resulting solution is supersaturated. | | |
a. | 1 only | b. | 2
only | c. | 3
only | d. | 1 and
2 | e. | 2 and
3 | | |
|
|
|
8.
|
The
Henry's law constant for N2 in water at 37 °C is 8.2 ´ 10-7 M/mm Hg. What is the equilibrium concentration
of N2 in water when the partial pressure of N2 is 634 mm Hg? a. | 1.3 x
10-9
M | b. | 5.2 x
10-4
M | c. | 1.9 x
10-2
M | d. | 1.9 x
103
M | e. | 7.7 x
108
M | | |
|
|
|
9.
|
Which
action(s) will decrease the equilibrium concentration of a non-reacting gas in
water?
1. | decreasing the temperature of the
water | 2. | decreasing the
volume of water | 3. | decreasing the pressure of the gas above the
liquid | | |
a. | 1
only | b. | 2
only | c. | 3
only | d. | 1 and
3 | e. | 1, 2, and
3 | | |
|
|
|
10.
|
Ideally, colligative properties depend only on the a. | concentration of
solute particles in a solution. | b. | identity of the solute particles in a
solution. | c. | color of a solution. | d. | hydrated radii
of the molecules or ions dissolved in a solution. | e. | partial pressure
of the gases above the surface of a solution. | | |
|
|
|
11.
|
The
vapor pressure of pure water at 45 °C is 71.9 mm Hg. What is the vapor pressure of a mixture of 21.0 g
sucrose (C12H22O11, molar mass 342.3 g/mol) and 79.0 g
water? a. | 0.992 mm
Hg | b. | 15.1 mm
Hg | c. | 19.1 mm
Hg | d. | 55.8 mm
Hg | e. | 70.9 mm
Hg | | |
|
|
|
12.
|
Which
of the following aqueous solutions should have the lowest freezing point? a. | pure
H2O | b. | 1 m NaBr | c. | 1 m
Ca(NO3)2 | d. | 1 m NH3 | e. | 1 m
C6H12O6 | | |
|
|
|
13.
|
Which
of the following aqueous solutions should have the lowest boiling point? a. | 0.50 m
KCl | b. | 0.50 m
Na2SO4 | c. | 0.50 m CaBr2 | d. | 1.5 m
KI | e. | 2.0 m
C6H12O6 | | |
|
|
|
14.
|
The
freezing point depression constant for water is -1.86 °C/m. At what temperature will a solution containing 7.99
g BaCl2 and 52.0 g H2O begin to freeze? Assume that no ion-pairing occurs
between Ba2+ and Cl-. a. | -4.12 °C | b. | -2.75 °C | c. | -1.37 °C | d. | -0.857 °C | e. | -0.248 °C | | |
|
|
|
15.
|
What
is the molar mass of a nonpolar molecular compound if 5.52 grams dissolved in 36.0 grams of benzene
begins to freeze at -1.87 °C? The freezing point of pure benzene is 5.50 °C and the
freezing point depression constant, Kfp, is -5.12 °C/m. a. | 46.1 g/mol | b. | 107
g/mol | c. | 216 g/mol | d. | 221
g/mol | e. | 419 g/mol | | |
|
|
|
16.
|
What
is the boiling point of a solution containing 2.33 g of caffeine,
C8H10N4O2, dissolved in 15.0 g of benzene? The boiling
point of pure benzene is 80.1 °C and the boiling point elevation constant, Kbp, is
2.53 °C/m. a. | 2.02 °C | b. | 78.1 °C | c. | 80.2 °C | d. | 82.1 °C | e. | 83.3 °C | | |
|
|
|
17.
|
What
mass of NaCl must be dissolved in 65.0 grams of water to lower the freezing point by 7.50
°C? The freezing
point depression constant, Kfp, for water is -1.86 °C/m.
Assume the van't Hoff factor for NaCl is 1.87. a. | 0.140 g | b. | 1.76
g | c. | 4.55
g | d. | 8.19
g | e. | 15.3
g | | |
|
|
|
18.
|
Which
of the following is an application of osmotic pressure? a. | salting meats
for preservation | b. | mixing water and ethylene glycol in
antifreeze | c. | pressurizing beverages with carbon
dioxide | d. | salting icy roads | e. | using a pressure
cooker to increase the boiling point of water | | |
|
|
|
19.
|
All
of the following are colloidal dispersions EXCEPT a. | ice cubes. | b. | cheese. | c. | butter. | d. | clouds. | e. | shaving cream. | | |
|
|
|
20.
|
Cheese and butter are colloidal dispersions that contain a liquid dispersed in a solid
medium. This type of colloid is called a(n) ____. a. | emulsion | b. | sol | c. | foam | d. | aerosol | e. | gel | | |
|