4) A sample of potassium nitrate (49.0 g) is dissolved in 101 g of water at 100°C, with precautions taken
to avoid evaporation of any water. The solution is cooled to 30.0°C and no precipitate is observed. This
solution is __________.
A) hydrated
B) placated
C) saturated
D) unsaturated
E) supersaturated
5) A sample of potassium chlorate (15.0 g) is dissolved in 201 g of water at 70°C, with precautions
taken to avoid evaporation of any water. The solution is cooled to 30.0°C and no precipitate is observed.
This solution is __________.
A) hydrated
B) miscible
C) saturated
D) unsaturated
E) supersaturated
6) A sample of potassium nitrate (49.0 g) is dissolved in 101 g of water at 100°C, with precautions taken
to avoid evaporation of any water. The solution is cooled to 30.0°C and a small amount of precipitate is
observed. This solution is __________.
A) hydrated
B) placated
C) saturated
D) unsaturated
E) supersaturated
7) The solubility of MnSO4 monohydrate in water at 20°C is 70.0 g per 100.0 mL of water. A solution
at 20°C that is 4.22 M in MnSO4 monohydrate is best described as a(n) __________ solution. The
formula weight of MnSO4 monohydrate is 168.97 g/mol.
A) hydrated
B) solvated
C) saturated
D) unsaturated
E) supersaturated
8) The solubility of MnSO4 monohydrate in water at 20°C is 70.0 g per 100.0 mL of water. A solution
at 20°C that is 0.401 M in MnSO4 monohydrate is best described as a(n) __________ solution. The
formula weight of MnSO4 monohydrate is 168.97 g/mol.
A) hydrated
B) solvated
C) saturated
D) unsaturated
E) supersaturated
9) A solution is prepared by dissolving 15.0 g of NH3 in 250.0 g of water. The density of the resulting
solution is 0.974 g/mL. The molarity of NH3 in the solution is __________.
A) 0.00353
B) 0.882
C) 60.0
D) 3.24
E) 3.53
10) A solution is prepared by dissolving 15.0 g of NH3 in 250.0 g of water. The density of the resulting
solution is 0.974 g/mL. The molality of NH3 in the solution is __________.
A) 0.00353
B) 0.882
C) 60.0
D) 3.24
E) 3.53
11) A solution is prepared by dissolving 23.7 g of CaCl2 in 375 g of water. The density of the resulting
solution is 1.05 g/mL. The concentration of Cl– in this solution is __________ M.
A) 0.214
B) 0.562
C) 1.12
D) 1.20
E) 6.64 × 10-2
12) A solution is prepared by dissolving 23.7 g of CaCl2 in 375 g of water. The density of the resulting
solution is 1.05 g/mL. The mole fraction of Cl– in this solution is __________ M.
A) 0.0103
B) 0.0200
C) 0.0201
D) 0.0632
E) 0.0630
13) A solution is prepared by dissolving 23.7 g of CaCl2 in 375 g of water. The density of the resulting
solution is 1.05 g/mL. The concentration of CaCl2 in this solution is __________ molal.
A) 0.214
B) 0.569
C) 5.70
D) 63.2
E) 1.76
14) A solution is prepared by dissolving 23.7 g of CaCl2 in 375 g of water. The density of the resulting
solution is 1.05 g/mL. The concentration of CaCl2 in this solution is __________ molar.
A) 0.564
B) 0.571
C) 0.569
D) 0.537
E) 0.214
15) The concentration of HCl in a solution that is prepared by dissolving 5.5 g of HCl in 200 g of
C2H6O is __________ molal.
A) 27.5
B) 7.5 × 10-4
C) 3.3 × 10-2
D) 0.75
E) 1.3
16) The concentration (M) of HCl in a solution prepared by dissolving 5.5 g of HCl in 200 g of C2H6O
is __________ M. The density of the solution is 0.79 g/mL.
A) 21
B) 0.93
C) 0.58
D) 6.0 × 10-4
E) 1.72
17) The mole fraction of HCl in a solution prepared by dissolving 5.5 g of HCl in 200 g of C2H6O is
__________ M. The density of the solution is 0.79 g/mL.
A) 0.027
B) 0.034
C) 0.028
D) 0.035
E) 0.151
18) The mole fraction of urea (MW = 60.0 g/mol) in a solution prepared by dissolving 16 g of urea in
39g of H2O is __________.
A) 0.58
B) 0.37
C) 0.13
D) 0.11
E) 9.1
19) The concentration of urea (MW = 60.0 g/mol) in a solution prepared by dissolving 16 g of urea in
39g of H2O is __________ molal.
A) 96
B) 6.8
C) 0.68
D) 6.3
E) 0.11
20) The molarity of urea in a solution prepared by dissolving 16 g of urea (MW = 60.0 g/mol) in 39g of
H2O is __________ M. The density of the solution is 1.3 g/mL.
A) 0.11
B) 3.7
C) 6.8
D) 6.3
E) 0.16
21) What is the molarity of sodium chloride in solution that is 13.0% by mass sodium chloride and that
has a density of 1.10 g/mL?
A) 143
B) 2.45
C) 2.56
D) 2.23
E) 1.43 × 10-2
22) What is the molality of sodium chloride in solution that is 13.0% by mass sodium chloride and that
has a density of 1.10 g/mL?
A) 2.23
B) 1.30
C) 2.56
D) 2.03
E) 1.10
23) What is the mole fraction of sodium chloride in solution that is 13.0% by mass sodium chloride and
that has a density of 1.10 g/mL?
A) 0.0442
B) 0.0462
C) 0.223
D) 0.483
E) 0.505
24) The vapor pressure of pure ethanol at 60°C is 0.459 atm. Raoult’s Law predicts that a solution
prepared by dissolving 10.0 mmol naphthalene (nonvolatile) in 90.0 mmol ethanol will have a vapor
pressure of __________ atm.
A) 0.498
B) 0.413
C) 0.790
D) 0.367
E) 0.0918
25) The vapor pressure of pure water at 25°C is 23.8 torr. What is the vapor pressure (torr) of water
above a solution prepared by dissolving 18.0 g of glucose (a nonelectrolyte, MW = 180.0 g/mol) in
95.0g of water?
A) 24.3
B) 23.4
C) 0.451
D) 0.443
E) 23.8
26) What is the freezing point (°C) of a solution prepared by dissolving 11.3 g of Ca(NO3)2 (formula
weight = 164 g/mol) in 115 g of water? The molal freezing point depression constant for water is
1.86°C/m.
A) -3.34
B) -1.11
C) 3.34
D) 1.11
E) 0.00
27) A solution containing 10.0 g of an unknown liquid and 90.0 g water has a freezing point of -3.33°C.
Given Kf = 1.86°C/m for water, the molar mass of the unknown liquid is ________g/mol.
A) 69.0
B) 333
C) 619
D) 161
E) 62.1
28) A solution containing 20.0 g of an unknown liquid and 110.0 g water has a freezing point of
-1.32 °C. Given Kf = 1.86°C/m for water, the molar mass of the unknown liquid is ________g/mol.
A) 256
B) 69.0
C) 333
D) 619
E) 78.1
29) A solution is prepared by dissolving 0.60 g of nicotine (a nonelectrolyte) in water to make 12 mL of
solution. The osmotic pressure of the solution is 7.55 atm at 25 °C. The molecular weight of nicotine is
________g/mol.
A) 28
B) 43
C) 50
D) 160
E) 0.60
30) A solution is prepared by dissolving 6.00 g of an unknown nonelectrolyte in enough water to make
1.00 L of solution. The osmotic pressure of this solution is 0.750 atm at 25.0°C. What is the molecular
weight (g/mol) of the unknown solute?
A) 16.4
B) 196
C) 110
D) 30.6
E) 5.12 × 10-3
31) An aqueous solution of a soluble compound (a nonelectrolyte) is prepared by dissolving 33.2 g of
the compound in sufficient water to form 250 mL of solution. The solution has an osmotic pressure of
1.2 atm at25°C. What is the molar mass (g/mole) of the compound?
A) 1.0 × 103
B) 2.7 × 103
C) 2.3 × 102
D) 6.8 × 102
E) 28
32) Determine the freezing point (°C) of a 0.015 molal aqueous solution of MgSO4. Assume i = 2.0 for
MgSO4. The molal freezing-point-depression constant of water is 1.86°C/m.
A) -0.056
B) -0.028
C) -0.17
D) -0.084
E) 0.000
33) A solution is prepared by dissolving 2.60 g of a strong electrolyte (formula weight = 101 g/mol) in
enough water to make 1.00 L of solution. The osmotic pressure of the solution is 1.25 atm at 25.0°C.
What is the van’t Hoff factor (i) for the unknown solute?
A) 0
B) 0.99
C) 1.98
D) 2.98
E) 0.630
34) George is making spaghetti for dinner. He places 4.01 kg of water in a pan and brings it to a boil.
Before adding the pasta, he adds 58 g of table salt (NaCl) to the water and again brings it to a boil. The
temperature of the salty, boiling water is __________°C.
Assume a pressure of 1.00 atm and negligible evaporation of water. Kb for water is 0.52°C/m.
A) 99.87
B) 100.26
C) 100.13
D) 99.74
E) 100.00
13.3 Algorithmic Questions
1) The Henry’s law constant for helium gas in water at 30°C is 3.70 × 10-4 M/atm. When the partial
pressure of helium above a sample of water is 0.650 atm, the concentration of helium in the water is
__________ M.
A) 5.69 × 10-4
B) 1.76 × 103
C) 1.30
D) 2.41 × 10-4
E) 3.70 × 10-4
2) The solubility of oxygen gas in water at 25°C and 1.0 atm pressure of oxygen is 0.041 g/L. The
solubility of oxygen in water at 3.0 atm and 25°C is __________ g/L.
A) 0.041
B) 0.014
C) 0.31
D) 0.12
E) 3.0
3) The solubility of nitrogen gas in water at 25°C and a nitrogen pressure of 1.0 atm is 6.9 × 10-4 M.
The solubility of nitrogen in water at a nitrogen pressure of 5.0 atm is __________ M.
A) 0.0035
B) .00086
C) 120
D) 0.00055
E) 5.0
4) On a clear day at sea level, with a temperature of 25°C, the partial pressure of N2 in air is 0.78 atm
and the concentration of nitrogen in water is 5.3 × 10-4 M. When the partial pressure of N2 is
__________ atm, the concentration in water is 1.1 × 10-3 M.
A) 0.63
B) 0.78
C) 1.0
D) 2.1
E) 1.6
5) A solution is prepared by dissolving 22.7 g of CaCl2 in 375 g of water. The density of the resulting
solution is 1.05 g/mL. The concentration of CaCl2 is __________% by mass.
A) 5.71
B) 5.99
C) 0.0599
D) 0.0571
E) 6.24
6) The concentration of urea in a solution prepared by dissolving 16 g of urea in 20 g of H2O is
__________% by mass. The molar mass of urea is 60.0 g/mol.
A) 44
B) 80
C) 0.44
D) 0.80
E) 0.48
7) The concentration of nitrate ion in a solution that contains 0.900 M aluminum nitrate is _______ M.
A) 0.900
B) 0.450
C) 0.300
D) 2.70
E) 1.80
8) The concentration of KBr in a solution prepared by dissolving 2.13 g of KBr in 897 g of water is
__________ molal.
A) 2.46
B) 0.0000207
C) 0.0200
D) 0.0167
E) 0.0186
9) The concentration of lead nitrate (Pb(NO3)2)) in a 0.626 M solution is __________ molal. The
density of the solution is 1.202 g/mL.
A) 0.521
B) 1.83
C) 0.629
D) 0.819
E) 0.650
10) The concentration of a benzene solution prepared by mixing 11.0 g C6H6 with 38.0 g CCl4 is
__________ molal.
A) 3.71
B) 2.40
C) 0.622
D) 0.289
E) 0.508
11) A solution is prepared by dissolving 14.0 g of NH3 in 250.0 g of water. The density of the resulting
solution is 0.974 g/mL. The mole fraction of NH3 in the solution is __________.
A) 0.0550
B) 0.0560
C) 0.940
D) 0.922
E) 16.8
12) A solution is prepared by adding 1.43 mol of KCl to 889 g of water. The concentration of KCl is
__________ molal.
A) 1.61 × 10-3
B) 622
C) 0.622
D) 1.27 × 103
E) 1.61
13) A solution is prepared by dissolving 16.2 g of benzene (C6H6) in 282 g of carbon tetrachloride
(CCl4). The concentration of benzene in this solution is __________ molal. The molar masses of C6H6
and CCl4 are 78.0 g/mol and 154 g/mol, respectively.
A) 7.36 × 10-4
B) 0.736
C) 0.102
D) 0.0543
E) 5.43
14) At 20°C, an aqueous solution that is 24.0% by mass in ammonium chloride has a density of
1.0674g/mL. What is the molarity of ammonium chloride in the solution? The formula weight of
NH4Cl is 53.50 g/mol.
A) 5.90
B) 0.479
C) 4.79
D) 0.0445
E) 22.5
15) At 20°C, a 2.32 M aqueous solution of ammonium chloride has a density of 1.0344 g/mL. What is
the molality of ammonium chloride in the solution? The formula weight of NH4Cl is 53.50 g/mol.
A) 2.55
B) 0.0449
C) 2.32
D) 0.446
E) 12.00
16) At 20°C, a 0.376 M aqueous solution of ammonium chloride has a density of 1.0045 g/mL. What is
the mass % of ammonium chloride in the solution? The formula weight of NH4Cl is 53.50 g/mol.
A) 0.381
B) 0.705
C) 0.374
D) 2.68
E) 2.00
17) The mole fraction of He in a gaseous solution prepared from 3.0 g of He, 6.5 g of Ar, and 10.0 g of
Ne is __________.
A) 0.53
B) 0.75
C) 0.20
D) 0.66
E) 0.86
18) The concentration of sodium chloride in an aqueous solution that is 2.23 M and that has a density of
1.01 g/mL is __________% by mass.
A) 2.21
B) 7.83
C) 45.3
D) 12.9
E) 10.1
19) A solution is prepared by dissolving 7.00 g of glycerin (C3H8O3) in 201 g of ethanol (C2H5OH).
The freezing point of the solution is __________°C. The freezing point of pure ethanol is -114.6°C at 1
atm. The molal-freezing-point-depression constant (Kf) for ethanol is 1.99°C/m. The molar masses of
glycerin and of ethanol are 92.1 g/mol and 46.1 g/mol, respectively.
A) -121.3
B) 0.752
C) -107.9
D) -113.8
E) -115.4
20) The vapor pressure of pure water at 25°C is 23.8 torr. Determine the vapor pressure (torr) of water at
25°C above a solution prepared by dissolving 21 g of urea (a nonvolatile, non-electrolyte, MW =
60.0g/mol) in 75 g of water.
A) 2.9
B) 0.35
C) 22
D) 27
E) 0.92
21) The freezing point of ethanol (C2H5OH) is -114.6°C. The molal freezing point depression constant
for ethanol is 2.00°C/m. What is the freezing point (°C) of a solution prepared by dissolving 40.0 g of
glycerin (C3H8O3, a nonelectrolyte) in 200.0 g of ethanol?
A) -115.0
B) -4.34
C) -132.3
D) -118.9
E) -114.6
22) Calculate the freezing point of a 0.08500 m aqueous solution of glucose. The molal freezing-point–
depression constant of water is 1.86°C/m.
A) 0.0425
B) 0.106
C) -0.0562
D) -0.158
E) -0.316
23) Calculate the freezing point of a 0.08500 m aqueous solution of NaNO3. The molal freezing-point-
depression constant of water is 1.86°C/m.
A) 0.0425
B) -0.0790
C) 0.0790
D) -0.158
E) -0.316
24) Calculate the freezing point of a solution containing 5.0 grams of KCl and 550.0 grams of water.
The molal-freezing-point-depression constant (Kf) for water is 1.86°C/m.
A) -0.45°C
B) +0.45°C
C) -0.23°C
D) +0.23°C
E) 1.23°C
25) The osmotic pressure of a solution formed by dissolving 25.0 mg of aspirin (C9H8O4) in 0.250 L of
water at 25°C is __________ atm.
A) 13.6
B) 1.14 × 10-3
C) 0.0136
D) 2.45
E) 1.38
26) A solution is prepared by adding 30.00 g of lactose (milk sugar) to 110.0 g of water at 55°C. The
partial pressure of water above the solution is __________ torr. The vapor pressure of pure water at
55°C is 118.0 torr. The MW of lactose is 342.3 g/mol.
A) 1.670
B) 94.1
C) 169.4
D) 116.3
E) 92.7
13.4 Short Answer Questions
1) The formula weight of FeCl3.6H2O is __________.
2) Water (H2O) and the alcohol methanol (CH3OH) are infinitely soluble in each other. The primary
intermolecular force responsible for this is __________.
3) For a dilute aqueous solution, a concentration of 1 ppm also corresponds to a concentration of 1
__________ per liter of solution.
4) For a dilute aqueous solution, a concentration of 1 ppb also corresponds to a concentration of 1
__________ per liter of solution.
5) What is the osmotic pressure (in atm) of a 0.040 M solution of a non-electrolyte at 30.0°C?
6) Physical properties of a solution that depend on the quantity of the solute particles present, but not the
kind or identity of the particles, are termed __________ properties.
7) A solution contains 150.8 grams of NaCl in 678.3 grams of water. Calculate the vapor pressure
lowering (in torr) of the solution at 25.0°C. (Note: The vapor pressure of pure water at 25.0°C is 23.76
torr.)
8) A solution contains 150.8 grams of NaCl in 678.3 grams of water. Calculate the vapor pressure of
water (in torr) over the solution at 25.0°C. (Note: The vapor pressure of pure water at 25.0°C is 23.76
torr.)
9) The phenomenon used to differentiate colloids and true solutions is called the __________ effect.
13.5 True/False Questions
1) A solution with a solute concentration greater than the solubility is called a supercritical solution.
2) Adding a nonvolatile solute to a solution decreases the vapor pressure of the solution.
3) After swimming in the ocean for several hours, swimmers noticed that their fingers appeared to be
very wrinkled. This is an indication that seawater is supertonic relative to the fluid in cells.
4) The value of the boiling-point-elevation constant (Kb) depends on the identity of the solvent.
5) Emulsifying agents typically have a hydrophobic end and a hydrophilic end.