Deck 12: Physical Properties of Solutions

Question 1

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

A) HCl
B) H₂O
C) CH₃OH
D) NH₃
E) CS₂

Answer 1

CS₂

Question 2

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 2

2, 3

Question 3

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

Answer 3

18.0 m

Question 4

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 5

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 6

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 7

Which of the following compounds should be soluble in CCl₄

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

Question 8

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%

Question 9

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 10

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 11

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 12

A 9.50 % by mass solution of acetone (C₃H₆O) in water has a density of 0.9849 g/mL at 20 ^$\circ$ 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

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 ^$\circ$ 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 14

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 15

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 16

A 20.0 % by mass solution of phosphoric acid (H₃PO₄) in water has a density of 1.114 g/mL at 20 ^$\circ$ 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 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

The heat of solution

A)is never positive $(\Delta{H}^{\circ}_{soln} \leq 0)$ , because the solute-solvent attraction is never weaker than the combination of the solute-solute attraction and solvent-solvent attraction.
B)is always positive $(\Delta{H}^{\circ}_{soln} > 0)$ , 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 ^$\circ$ _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 $(\Delta{H}^{\circ}_{soln} < 0)$ , 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 19

Which one of the following would be immiscible with water

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

Question 20

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 21

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 22

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 23

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 24

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 25

Oxygen gas makes up 21 % of the atmosphere by volume. What is the solubility of O₂(g) in water at 25 ^$\circ$ C if the atmospheric pressure is 741 mmHg The Henry's law constant for oxygen gas at 25 ^$\circ$ 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 26

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 27

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) 1000. g
D) 1,263 g
E) 7,917 g

Question 28

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 29

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 30

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 31

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 32

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 33

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 34

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 35

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 36

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 37

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 38

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 39

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 40

The solubility of nitrogen gas at 25 ^$\circ$ 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 41

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 ^$\circ$ C/m.

A) +0.10 ^$\circ$ C
B) +0.186 ^$\circ$ C
C) -0.10 ^$\circ$ C
D) -0.186 ^$\circ$ C
E) -1.03 ^$\circ$ C

Question 42

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

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

Question 43

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 ^$\circ$ C and its K_f value is 5.12 ^$\circ$ C/m.

A) -1.16 ^$\circ$ C
B) 0.98 ^$\circ$ C
C) 5.49 ^$\circ$ C
D) 6.66 ^$\circ$ C
E) 12.2 ^$\circ$ C

Question 44

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 ^$\circ$ C

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

Question 45

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 a 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 46

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

A) 8.94 ^$\circ$ C
B) 0.99 ^$\circ$ C
C) -0.99 ^$\circ$ C
D) -8.94 ^$\circ$ C
E) -366 ^$\circ$ C

Question 47

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 48

A solution is 40.0% by mass benzene (C₆H₆) in carbon tetrachloride (CCl₄) at 20 ^$\circ$ 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 ^$\circ$ C:

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

Question 49

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 ^$\circ$ 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 ^$\circ$ 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 50

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

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

Question 51

The vapor pressure of water at 20 ^$\circ$ 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 52

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 53

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 ^$\circ$ C K_f of benzene is 5.12 ^$\circ$ 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 54

Which of the following aqueous solutions has the highest osmotic pressure at 25 ^$\circ$ 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 55

The vapor pressure of water at 45.0 ^$\circ$ 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 56

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 ^$\circ$ C/m.

A) 17.6 ^$\circ$ C
B) 1.50 ^$\circ$ C
C) -1.50 ^$\circ$ C
D) -17.6 ^$\circ$ C
E) -176 ^$\circ$ C

Question 57

At 10 ^$\circ$ 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 58

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 59

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 60

A solution is 35.0% by mass carbon tetrachloride (CCl₄) in benzene (C₆H₆) at 20 ^$\circ$ 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 ^$\circ$ 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

0.102 g of an unknown compound dissolved in 100. mL of water has an osmotic pressure of 28.1 mmHg at 20 ^$\circ$ C. Calculate the molar mass of the compound.

A) 727 g/mol
B) 663 g/mol
C) 1.10 * 10² g/mol
D) 1.15 g/mol
E) 0.872 g/mol

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

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 ^$\circ$ C

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

Question 65

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 ^$\circ$ 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

Question 66

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 67

The vapor pressure of water at 45.0 ^$\circ$ 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 68

What is the osmotic pressure of a 0.25 M solution of sucrose at 37 ^$\circ$ 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 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 ^$\circ$ C. What is the molar mass of sucrose K_f of water is 1.86 ^$\circ$ C/m.

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

Question 70

The osmotic pressure of a 0.010 M MgSO₄ solution at 25 ^$\circ$ 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 71

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 72

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

A) 93.0 ^$\circ$ C
B) 97.7 ^$\circ$ C
C) 102.3 ^$\circ$ C
D) 104.7 ^$\circ$ C
E) 107.0 ^$\circ$ C

Question 73

Pure benzene, C₆H₆, freezes at 5.5 ^$\circ$ C and boils at 80.1 ^$\circ$ 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 ^$\circ$ C (For benzene, K_f = 5.12 ^$\circ$ C/m, K_b = 2.53 ^$\circ$ C/m; for cyclohexane, K_f = 20.0 ^$\circ$ C/m, K_b = 2.79 ^$\circ$ C/m)

A) 77.4 ^$\circ$ C
B) 80.9 ^$\circ$ C
C) 82.8 ^$\circ$ C
D) 83.1 ^$\circ$ C
E) 91.2 ^$\circ$ C

Question 74

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 ^$\circ$ C. Find the temperature at which this solution freezes. [Given: for water K_f = 1.86 ^$\circ$ C/m; molecular mass of fructose = 180.16 g/mol]

A) -1.30 ^$\circ$ C
B) -1.41 ^$\circ$ C
C) -1.52 ^$\circ$ C
D) -1.57 ^$\circ$ C
E) -1.69 ^$\circ$ C

Question 75

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 ^$\circ$ C/m)

A) 0.1 ^$\circ$ C
B) 99.9 ^$\circ$ C
C) 100.1 ^$\circ$ C
D) 102.2 ^$\circ$ C
E) 105.7 ^$\circ$ C

Question 76

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 ^$\circ$ C/m)

A) 99.8 ^$\circ$ C
B) 99.9 ^$\circ$ C
C) 100.1 ^$\circ$ C
D) 100.2 ^$\circ$ C
E) 100.4 ^$\circ$ C

Question 77

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

A) 0.22 ^$\circ$ C
B) 0.429 ^$\circ$ C
C) 99.78 ^$\circ$ C
D) 100.22 ^$\circ$ C
E) 100.43 ^$\circ$ C

Question 78

An aqueous dextrose solution having a density of 1.04 g/cm³ freezes at -1.15 ^$\circ$ C. Find the osmotic pressure of this solution at 25 ^$\circ$ C. K_f of water is 1.86 ^$\circ$ 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 79

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 ^$\circ$ C/m.]

A) -13.4 ^$\circ$ C
B) -6.68 ^$\circ$ C
C) -3.59 ^$\circ$ C
D) 3.59 ^$\circ$ C
E) 6.68 ^$\circ$ C

Question 80

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 ^$\circ$ C/m)

A) 99.4 ^$\circ$ C
B) 100.0 ^$\circ$ C
C) 100.6 ^$\circ$ C
D) 106.2 ^$\circ$ C
E) 108.4 ^$\circ$ C