Deck 12: Physical Properties of Solutions

Question 1

Which response lists all the following pairs that are miscible liquids. Pair #1: octane (C₈H₁₈)and water
Pair #2: acetic acid (CH₃COOH)and water
Pair #3: octane (C₈H₁₈)and carbon tetrachloride(CCl₄)

A)1, 3
B)1, 2
C)3
D)2
E)2, 3

Answer 1

2, 3

Question 2

Calculate the mass percent of HOCH₂CH₂OH in a solution made by dissolving 3.2 g of HOCH₂CH₂OH in 43.5g of water.

A)2.9%
B)6.9%
C)7.4%
D)22%
E)29%

Answer 2

6.9%

Question 3

Which of the following liquids would make a good solvent for iodine, I₂?

A)HCl
B)H₂O
C)CH₃OH
D)NH₃
E)CS₂

Answer 3

CS₂

Question 4

Which one of the following would be immiscible with water?

A)A
B)B
C)C
D)D
E)E

Question 5

A 1.35 m solution of NaOCl in water is prepared.What is the mole fraction of the NaOCl?

A)0.0135
B)0.0243
C)0.0271
D)0.0237
E)0.0263

Question 6

What is the molarity of a solution that is 7.00% by mass magnesium sulfate and has a density of 1.071 g/mL?

A)0.0890 M
B)0.496 M
C)0.543 M
D)0.623 M
E)1.32 M

Question 7

The heat of solution

A)is never positive ( $\Delta$ H°_soln $\le$ 0), because the solute-solvent attraction is never weaker than the combination of the solute-solute attraction and solvent-solvent attraction.
B)is always positive ( $\Delta$ H°_soln > 0), because the solute-solvent attraction is always weaker than the combination of the solute-solute attraction and solvent-solvent attraction.
C)is always zero ( $\Delta$ H°_soln = 0), because the solute-solvent attraction is defined as the average of the solute-solute attraction and solvent-solvent attraction.
D)is always negative ( $\Delta$ H°_soln < 0), because the solute-solvent attraction is always stronger than the combination of the solute-solute attraction and solvent-solvent attraction.
E)may be positive, zero, or negative, depending on the relative strength of the solute-solvent, solute-solute, and solvent-solvent attractive forces.

Question 8

What is the percent by mass of a Na₂SO₄ solution in water with a mole fraction of Na₂SO₄, X = 0.350 ?

A)2.76%
B)4.25%
C)19.1%
D)73.4 %
E)80.9%

Question 9

A 15.00 % by mass solution of lactose (C₁₂H₂₂O₁₁, 342.30 g/mol)in water has a density of 1.0602 g/mL at 20°C.What is the molarity of this solution?

A)0.03097 M
B)0.4133 M
C)0.4646 M
D)1.590 M
E)3.097 M

Question 10

Which of the following compounds should be soluble in CCl₄?

A)NaCl
B)H₂O
C)NaOH
D)C₈H₁₈
E)None of these

Question 11

A solution that is 33.6 % by mass of phenol (C₆H₅OH)in water is prepared.What is the mole fraction of the phenol?

A)0.0969
B)0.0643
C)0.0883
D)0.0604
E)0.357

Question 12

A 9.50 % by mass solution of acetone (C₃H₆O)in water has a density of 0.9849 g/mL at 20°C.What is the molarity of this solution?

A)0.621 M
B)1.61 M
C)1.66 M
D)1.71 M
E)16.9 M

Question 13

Calculate the mole fraction of KI in a solution made by dissolving 3.4 g of KI in 5.8 g of water.

A)0.060
B)0.064
C)0.37
D)0.59
E)6.4

Question 14

What is the molality of an aqueous KBr solution with a mole fraction of KBr, X, equal to 0.245?

A)0.325 m
B)0.682 m
C)13.6 m
D)18.0 m
E)29.2 m

Question 15

In which of the following solvents would you expect KBr to be most soluble?

A)C₆H₁₄ (hexane)
B)CH₃CH₂OH (ethanol)
C)C₆H₆ (benzene)
D)CCl₄ (carbon tetrachloride)
E)C₆H₁₂ (cyclohexane)

Question 16

An endothermic solution process is described by which of the following?

A)( $\Delta$ H > 0, solution feels cold)
B)( $\Delta$ H > 0, solution feels hot)
C)( $\Delta$ H < 0, solution feels cold)
D)( $\Delta$ H < 0, solution feels hot)
E)( $\Delta$ H = 0)

Question 17

A saturated solution

A)contains more solute than solvent.
B)contains more solvent than solute.
C)contains equal moles of solute and solvent.
D)contains the maximum amount of solute that will dissolve in that solvent at that temperature.
E)contains a solvent with only sigma bonds and no pi bonds (i.e.only single bonds, with no double or triple bonds).

Question 18

Which of the following gives the molarity of a 17.0% by mass solution of sodium acetate, CH₃COONa (molar mass = 82.0 g/mol)in water? The density of the solution is 1.09 g/mL.

A)2.26 × 10^-6 M
B)0.207 M
C)2.07 M
D)2.26 M
E)2.72 M

Question 19

A 20.0 % by mass solution of phosphoric acid (H₃PO₄)in water has a density of 1.114 g/mL at 20°C.What is the molarity of this solution?

A)0.0114 M
B)0.0568 M
C)0.114 M
D)2.27 M
E)11.4 M

Question 20

An exothermic solution process is described by which of the following?

A)( $\Delta$ H > 0, solution feels cold)
B)( $\Delta$ H > 0, solution feels hot)
C)( $\Delta$ H < 0, solution feels cold)
D)( $\Delta$ H < 0, solution feels hot)
E)( $\Delta$ H = 0)

Question 21

Calculate the molality of 6.0 M H₂SO₄ solution.The density of the solution is 1.34 g/mL.

A)4.48 m
B)7.98 m
C)8.10 m
D)8.43 m
E)10.2 m

Question 22

Calculate the percent by mass of potassium nitrate in a solution made from 45.0 g KNO₃ and 295 mL of water.The density of water is 0.997 g/mL.

A)1.51 %
B)7.57 %
C)13.3 %
D)15.2 %
E)None of these

Question 23

Which of the following solutions has the largest molality of HCl?

A)4.5 m HCl
B)mole fraction, X = 0.110 HCl
C)15.0 mass % HCl
D)10.5 g HCl in 750 g of H₂O
E)3.6 moles HCl in 45.0 moles of H₂O

Question 24

Determine the mass percent HCl in a 1.2 M solution of hydrochloric acid with a density of 1.019 g/mL?

A)3.0 %
B)4.3 %
C)8.6 %
D)13%
E)30.%

Question 25

What is the percent CdSO₄ by mass in a 1.00 m aqueous CdSO₄ solution?

A)1.00 × 10^-3 %
B)0.100 %
C)17.2 %
D)20.8 %
E)24.4 %

Question 26

Calculate the molality of a 20.0% by mass ammonium sulfate (NH₄)₂SO₄ solution.The density of the solution is 1.117 g/mL.

A)0.150 m
B)1.51 m
C)1.70 m
D)1.89 m
E)2.10 m

Question 27

What is the molality of a solution that is 3.68 % by mass calcium chloride.

A)0.0332 m
B)0.332 m
C)0.344 m
D)0.464 m
E)0.506 m

Question 28

In how many grams of water should 25.31 g of potassium nitrate (KNO₃)be dissolved to prepare a 0.1982 m solution?

A)250.0 g
B)792.0 g
C)1,000.g
D)1,263 g
E)7,917 g

Question 29

A 23.0% by mass LiCl solution is prepared in water.What is the mole fraction of the water?

A)0.113
B)0.127
C)0.873
D)0.887
E)0.911

Question 30

The solubility of nitrogen gas at 25°C and a nitrogen pressure of 522 mmHg is 4.7 × 10^-4 mol/L.What is the value of the Henry's Law constant in mol/L·atm?

A)9.0 × 10^-7 mol/L·atm
B)3.2 × 10^-4 mol/L·atm
C)4.7 × 10^-4 mol/L·atm
D)6.8 × 10^-4 mol/L·atm
E)1.5 × 10³ mol/L·atm

Question 31

The density of a 20.3 M CH₃OH (methanol)solution is 0.858 g/mL.What is the molality of this solution? H₂O is the solvent.

A)17.4 m
B)20.8 m
C)23.7 m
D)70.0 m
E)97.6 m

Question 32

Calculate the molality of a 15.0% by mass solution of MgCl₂ in H₂O.The density of this solution is 1.127 g/mL.

A)0.0134 m
B)0.157 m
C)1.58 m
D)1.86 m
E)11.8 m

Question 33

The solubility of gases in water usually increases with

A)increasing pressure and increasing temperature
B)increasing temperature and decreasing pressure
C)decreasing temperature and increasing pressure
D)decreasing temperature and decreasing pressure
E)increasing temperature only

Question 34

Oxygen gas makes up 21 % of the atmosphere by volume.What is the solubility of O₂(g)in water at 25°C if the atmospheric pressure is 741 mmHg? The Henry's law constant for oxygen gas at 25°C is 1.3 × 10^-3 mol/L·atm.

A)2.7 × 10^-4 M
B)1.3 × 10^-3 M
C)6.2 × 10^-3 M
D)9.6 × 10^-3 M
E)0.96 M

Question 35

What is the mass percent CH₃OH of a 0.256 m CH₃OH(aq)solution.

A)0.819 %
B)0.992 %
C)1.23 %
D)1.29 %
E)1.51 %

Question 36

Which of the following gases is expected to have a higher solubility in water than what is predicted using Henry's law?

A)N₂
B)CH₄
C)Ar
D)NH₃
E)H₂

Question 37

How many grams of water are needed to dissolve 27.8 g of ammonium nitrate NH₄NO₃ in order to prepare a 0.452 m solution?

A)769 g
B)36.2 g
C)100.g
D)0.157 g
E)157 g

Question 38

Which of the following aqueous solutions has the largest molality of benzoic acid (C₆H₅COOH)?

A)3.5 m C₆H₅COOH
B)mole fraction, X = 0.050 C₆H₅COOH
C)2.50 mass % C₆H₅COOH
D)3.2 g C₆H₅COOH in 650.g of H₂O
E)1.5 moles C₆H₅COOH in 65.0 moles of H₂O

Question 39

Calculate the molality of a solution containing 14.3 g of NaCl in 42.2 g of water.

A)2.45 × 10^-4 m
B)5.80 × 10^-4 m
C)2.45 × 10^-1 m
D)103 m
E)5.80 m

Question 40

What is the percent CsCl by mass in a 0.711 M CsCl solution that has a density of 1.091 g/mL?

A)3.87 × 10^-4 %
B)3.87 × 10^-1 %
C)11.0 %
D)1.10 %
E)6.50 × 10^-2 %

Question 41

Calculate the freezing point of a solution made from 22.0 g of octane (C₈H₁₈)dissolved in 148.0 g of benzene.Benzene freezes at 5.50°C and its K_f value is 5.12°C/m.

A)-1.16°C
B)0.98°C
C)5.49°C
D)6.66°C
E)12.2°C

Question 42

What is the freezing point of a solution prepared from 50.0 g ethylene glycol (C₂H₆O₂)and 85.0 g H₂O? K_f of water is 1.86°C/m.

A)17.6°C
B)1.50°C
C)-1.50°C
D)-17.6°C
E)-176°C

Question 43

According to Raoult's law, which statement is false?

A)The vapor pressure of a solvent over a solution decreases as its mole fraction increases.
B)The solubility of a gas increases as the temperature decreases.
C)The vapor pressure of a solvent over a solution is less than that of pure solvent.
D)The greater the pressure of a gas over a solution the greater its solubility.
E)Ionic solutes dissociate in solution causing an enhancement of all colligative properties.

Question 44

The vapor pressure of water at 20°C is 17.5 mmHg.What is the vapor pressure of water over a solution prepared from 2.00 × 10² g of sucrose (C₁₂H₂₂O₁₁)and 3.50 × 10² g water?

A)0.51 mmHg
B)16.0 mmHg
C)17.0 mmHg
D)18.0 mmHg
E)19.4 mmHg

Question 45

What is the molar mass of toluene if 0.85 g of toluene depresses the freezing point of 100.g of benzene by 0.47°C? K_f of benzene is 5.12°C/m.

A)927 g/mol
B)92.6 g/mol
C)81.8 g/mol
D)78.0 g/mol
E)10.7 g/mol

Question 46

The vapor pressure of water at 45.0 °C is 71.93 mmHg.What is the vapor pressure of water over a solution prepared from 75.0 g of citric acid (C₆H₈O₇)in 0.420 kg of water at this temperature?

A)1.22 mmHg
B)42.3 mmHg
C)43.0 mmHg
D)70.7 mmHg
E)73.2 mmHg

Question 47

During osmosis

A)pure solvent diffuses through a membrane but solutes do not.
B)pure solutes diffuse through a membrane but solvent does not.
C)pure solvent and a solution both diffuse at the same time through a membrane.
D)gases diffuse through a membrane into a solution and build up pressure.

Question 48

Consider a solution made from a nonvolatile solute and a volatile solvent.Which statement is true?

A)The vapor pressure of the solution is always greater than the vapor pressure of the pure solvent.
B)The boiling point of the solution is always greater than the boiling point of the pure solvent.
C)The freezing point of the solution is always greater than the freezing point of the pure solvent.

Question 49

Which of the following aqueous solutions has the highest boiling point (assume 100% dissociation for all soluble ionic compounds)?

A)0.10m Al(NO₃)₃
B)0.11m Na₂SO₄
C)0.15m K₂CO₃
D)0.18m NaCl
E)0.35m C₆H₁₂O₆

Question 50

What is the freezing point of a solution that contains 10.0 g of glucose (C₆H₁₂O₆)in 100.g of H₂O? K_f for water is 1.86°C/m.

A)+0.10°C
B)+0.186°C
C)-0.10°C
D)-0.186°C
E)-1.03°C

Question 51

A solution of chloroform, CHCl₃, and acetone, (CH₃)₂CO, exhibits a negative deviation from Raoult's law.This result implies that

A)chloroform-chloroform interactions are stronger than chloroform-acetone interactions.
B)chloroform-chloroform interactions are weaker than chloroform-acetone interactions.
C)acetone-acetone interactions are stronger than chloroform-acetone interactions.
D)acetone-acetone interactions are weaker than chloroform-acetone interactions.
E)Both B and D.
F)Both A and C.

Question 52

What is the freezing point of an aqueous solution of a nonvolatile solute that has a boiling point of 102.5°C? For water K_f = 1.86°C/m and K_b = 0.52°C/m.

A)8.94°C
B)0.99°C
C)-0.99°C
D)-8.94°C
E)-366°C

Question 53

Which of the following aqueous solutions has the highest osmotic pressure at 25°C (assume 100% dissociation for all soluble ionic compounds)?

A)0.15m K₃PO₄
B)0.20m KI
C)0.25m K₂CO₃
D)0.30m NH₄NO₃
E)0.45m C₁₂H₂₂O₁₁

Question 54

At 10°C one volume of water dissolves 3.10 volumes of chlorine gas at 1.00 atm pressure.What is the Henry's Law constant in mol/L·atm?

A)0.043
B)0.13
C)3.1
D)3.8
E)36.

Question 55

When 24.0 g of glucose (a nonelectrolyte)are dissolved in 500.g of water, the solution has a freezing point of -0.47°C.What is the molar mass of glucose? K_f of water is 1.86°C/m.

A)41.9 g
B)47.5 g
C)54.9 g
D)178 g
E)190.g

Question 56

A solution that contains 55.0 g of ascorbic acid (VitaminC)in 250.g of water freezes at -2.34°C.Calculate the molar mass (in units of g/mol)of the solute.K_f of water is 1.86°C/m.

A)1.26
B)10.9
C)43.6
D)175
E)277

Question 57

The solubility of oxygen in lakes high in the Rocky Mountains is affected by the altitude.If the solubility of O₂ from the air is 2.67 × 10^-4 M at sea level and 25°C, what is the solubility of O₂ at an elevation of 12,000 ft where the atmospheric pressure is 0.657 atm? Assume the temperature is 25°C, and that the mole fraction of O₂ in air is 0.209 at both 12,000 ft and at sea level.

A)3.66 × 10^-5 M
B)1.75 × 10^-4 M
C)2.67 × 10^-4 M
D)4.06 × 10^-4 M
E)None of the above.

Question 58

A solution is 40.0% by mass benzene (C₆H₆)in carbon tetrachloride (CCl₄)at 20°C.The vapor pressure of pure benzene and pure carbon tetrachloride at this temperature is 74.61 mmHg and 91.32 mmHg, respectively.Calculate the vapor pressure of the solution at 20°C:

A)66.4 mmHg
B)73.8 mmHg
C)81.8 mmHg
D)83.0 mmHg
E)84.6 mmHg

Question 59

What is the osmotic pressure of a solution that contains 13.7 g of propyl alcohol (C₃H₇OH)dissolved in enough water to make 500.mL of solution at 27°C?

A)0.0100 atm
B)0.0140 atm
C)0.0370 atm
D)0.456 atm
E)11.2 atm

Question 60

A solution is 35.0% by mass carbon tetrachloride (CCl₄)in benzene (C₆H₆)at 20°C.The vapor pressure of pure benzene and pure carbon tetrachloride at this temperature is 74.61 mmHg and 91.32 mmHg, respectively.Calculate the vapor pressure of the solution at 20°C:

A)58.1 mmHg
B)78.2 mmHg
C)80.5 mmHg
D)82.9 mmHg
E)83.0 mmHg

Question 61

Assuming 100% dissociation, which of the following compounds is listed incorrectly with its van't Hoff factor i?

A)Na₂SO₄, i = 3
B)NH₄NO₃, i = 2
C)Sucrose, i = 1
D)Al₂(SO₄)₃, i = 4
E)Mg(NO₃)₂, i = 3

Question 62

What is the boiling point of a solution of 12.0 g of urea (CH₄N₂O)in 165.0 g of water? (K_b (H₂O)= 0.52 °C/m)

A)99.4°C
B)100.0 °C
C)100.6°C
D)106.2°C
E)108.4°C

Question 63

Arrange the following aqueous solutions in order of increasing boiling points: 0.050m Mg(NO₃)₂; 0.100m ethanol; 0.090m NaCl.

A)Mg(NO₃)₂ < NaCl < ethanol
B)ethanol < Mg(NO₃)₂ < NaCl
C)ethanol < NaCl < Mg(NO₃)₂
D)NaCl < ethanol < Mg(NO₃)₂
E)Mg(NO₃)₂ < ethanol < NaCl

Question 64

An aqueous fructose solution having a density of 1.049 g/cm³ is found to have an osmotic pressure of 17.0 atm at 25°C.Find the temperature at which this solution freezes.[Given: for water K_f = 1.86 °C/m; molecular mass of fructose = 180.16 g/mol]

A)-1.30°C
B)-1.41°C
C)-1.52°C
D)-1.57°C
E)-1.69°C

Question 65

Arrange the following aqueous solutions in order of increasing boiling points: 0.300m C₆H₁₂O₆, 0.110m K₂CO₃, and 0.050m Al(ClO₄)₃

A)C₆H₁₂O₆ < K₂CO₃ < Al(ClO₄)₃
B)Al(ClO₄)₃ < C₆H₁₂O₆ < K₂CO₃
C)C₆H₁₂O₆ < Al(ClO₄)₃ < K₂CO₃
D)K₂CO₃ < C₆H₁₂O₆ < Al(ClO₄)₃
E)K₂CO₃ < Al(ClO₄)₃ < C₆H₁₂O₆

Question 66

The vapor pressure of water at 45.0 °C is 71.93 mmHg.Calculate the vapor pressure of a solution of 1.50m K₂CO₃ at this temperature (assume 100% dissociation)

A)1.89 mmHg
B)5.39 mmHg
C)66.5 mmHg
D)70.0 mmHg
E)108 mmHg

Question 67

An aqueous dextrose solution having a density of 1.04 g/cm³ freezes at -1.15°C.Find the osmotic pressure of this solution at 25°C.K_f of water is 1.86 °C/m; molecular mass of dextrose = 180.16 g/mol.

A)12.9 atm
B)13.8 atm
C)14.1 atm
D)15.1 atm
E)120 atm

Question 68

What is the boiling point of an aqueous solution of a nonelectrolyte that has an osmotic pressure of 10.50 atm at 25°C? K_b of water is 0.52°C/m.Assume the density of the solution is the same as that of pure water.

A)0.22°C
B)0.429°C
C)99.78°C
D)100.22°C
E)100.43°C

Question 69

When 12.1 g of the sugar sucrose (a nonelectrolyte)is dissolved in exactly 800.0 g of water, the solution has a freezing point of -0.082°C.What is the molar mass of sucrose? K_f of water is 1.86°C/m.

A)426 g
B)99.2 g
C)178 g
D)266 g
E)343 g

Question 70

The vapor pressure of water at 45.0 °C is 71.93 mmHg.Calculate the vapor pressure of a solution of 1.25m Al(ClO₃)₃ at this temperature (assume 100% dissociation)

A)360.mmHg
B)89.9 mmHg
C)71.9 mmHg
D)70.4 mmHg
E)66.0 mmHg

Question 71

Calculate the approximate freezing point of a solution made from 21.0 g NaCl and 1.00 × 10² g of H₂O.[K_f of water is 1.86°C/m.]

A)-13.4°C
B)-6.68°C
C)-3.59°C
D)3.59°C
E)6.68°C

Question 72

If 14.2 g of Al(NO₃)₃ is dissolved in 655g of water, what is the boiling point of the solution (assume 100% dissociation, K_b (H₂O)= 0.52 °C/m)?

A)99.8°C
B)99.9°C
C)100.1°C
D)100.2°C
E)100.4°C

Question 73

What is the osmotic pressure of a 0.25 M solution of sucrose at 37°C? (R = 0.0821 L.atm/K.mol)

A)6.6 × 10^-5 atm
B)0.76 atm
C)6.4 atm
D)100 atm
E)940 atm

Question 74

The osmotic pressure of a 0.010 M MgSO₄ solution at 25°C is 0.318 atm.Calculate i, the van't Hoff factor, for this MgSO₄ solution.

A)0.013
B)1.3
C)1.5
D)2.0
E)76.8

Question 75

Calculate the boiling point of a 4.5 m solution of Na₂SO₄ in water (assume 100% dissociation, K_b (H₂O)= 0.52 °C/m)

A)93.0 °C
B)97.7 °C
C)102.3°C
D)104.7°C
E)107.0°C

Question 76

Assuming 100% dissociation, which of the following compounds is listed correctly with its van't Hoff factor i?

A)Ca(ClO₃)₂, i = 2
B)(NH₄)₂SO₄, i = 3
C)(NH₄)₃PO₄, i = 5
D)Urea, i = 2
E)Sc₂(SO₄)₃, i = 6

Question 77

What is the osmotic pressure of a solution prepared from 13.7 g of the electrolyte HCl and enough water to make 0.500 L of solution at 18°C?

A)0.55 atm
B)1.10 atm
C)8.95 atm
D)17.9 atm
E)35.9 atm

Question 78

What is the boiling point of a solution of 11.0 g of lactose (C₁₂H₂₂O₁₁)in 145.0g of water? (K_b (H₂O)= 0.52 °C/m)

A)0.1°C
B)99.9 °C
C)100.1°C
D)102.2 °C
E)105.7 °C

Question 79

Pure benzene, C₆H₆, freezes at 5.5° and boils at 80.1°C.What is the boiling point of a solution consisting of cyclohexane (C₆H₁₂)dissolved in benzene if the freezing point of this solution is 0.0°C? (For benzene, K_f = 5.12 °C/m, K_b = 2.53 °C/m; for cyclohexane, K_f = 20.0 °C/m, K_b = 2.79°C/m)

A)77.4°C
B)80.9°C
C)82.8°C
D)83.1°C
E)91.2°C

Question 80

How many grams of sucrose (C₁₂H₂₂O₁₁, 342.3 g/mol)would be needed to make 2.5 L of a solution with an osmotic pressure of 14 atm at 25°C? (R = 0.0821 L.atm/K.mol)

A)0.57 g
B)6.8 g
C)2.0 × 10² g
D)4.9 × 10² g
E)5.8 × 10³ g