Multiple
Choice
Identify the letter of the choice that best completes the statement or answers the
question.
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1.
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What is the molality of an aqueous 13.82%
by mass sulfuric acid solution? 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 | | |
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2.
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What is the mole fraction of
1.98 m Fe(NO3)3(aq)? The molar mass of Fe(NO3)3 is
241.9 g/mol and the molar mass of water is 18.02 g/mol. a. | 0.0345 | b. | 0.0641 | c. | 0.324 | d. | 0.479 | e. | 0.863 | | |
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3.
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Concentrated aqueous hydrofluoric acid
is 28.9 M and has a density of 1.18 g/mL. What is the weight percent of concentrated
HF?
a. | 24.5% | b. | 49.0% | c. | 51.0% | d. | 68.2% | e. | 75.5% | | |
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4.
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If the concentration of
potassium chloride in water is 113 ppm, what is the molarity of potassium chloride in water? The
molar mass of KCl is 74.55 g/mol. Assume the density of the solution is 1.00 g/mL. a. | 1.52 × 10-9
M | b. | 1.19 ×
10-4 M | c. | 1.52 ×
10-3 M | d. | 8.42 ×
10-3 M | e. | 0.660 M | | |
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5.
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The Henry's law constant for
O2 in water at 25 °C is 1.66 × 10-6 M/mm Hg. What partial pressure of O2 is necessary to
achieve an equilibrium concentration of 0.150 M O2? a. | 2.49 × 10-7 mm
Hg | b. | 6.23 ×
10-6 mm Hg | c. | 1.11 ×
10-5 mm Hg | d. | 9.04 ×
104 mm Hg | e. | 4.02 ×
106 mm Hg | | |
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6.
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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. | | |
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7.
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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 | | |
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8.
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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 | | |
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9.
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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 | | |
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10.
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What concentration unit is used
in the calculation of osmotic pressure for a dilute solution? a. | molality | b. | weight percent | c. | mass fraction | d. | mole fraction | e. | molarity | | |
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