Question 1

When a nonvolatile solute such as ammonium sulfate is dissolved in a solvent like water, one of the observed effects is

Accepted Answer

A)  a decrease in the vapor pressure of the solvent.
B)  an increase in the vapor pressure of the solute.
C)  an increase in the freezing point of the liquid.
D)  a decrease in the boiling point of the liquid.
E)  scattering of light beams by the solute particles in the solution. A

Question 2

Wax is a solid mixture of hydrocarbon compounds consisting of molecules with long chains of carbon atoms. Which solvent would you expect to be most capable of dissolving wax?

Accepted Answer

A)   
B)   
C)   
D)   
E)    E

Question 3

Many marine organisms that require oxygen live at ocean depths where high pressures and low temperatures would not support humans. Based on what you have learned in this chapter, what is one reason that organisms can survive under these conditions?

Accepted Answer

Oxygen becomes more soluble at higher pressures and colder temperatures, both of which are present at the "bottom"of the ocean. Thus, the environment is oxygen rich. These organisms must have adaptations that allow them to survive under high temperatures and low-pressures.

Question 4

Dry air is a mixture of gases in which the partial pressure of nitrogen gas at 1.000 atm is typically 0.78 atm while that of argon gas is 0.009 atm. A liquid sample was exposed to dry air at 1.000 atm and a given temperature and found to have a nitrogen gas concentration of 5.30 × 10⁻⁴ M. If argon were added to the dry air until the partial pressure of argon was now 0.400 atm, the concentration of nitrogen gas in the liquid sample would now be ________.Hint: Think of Dalton's law of partial pressures.

Accepted Answer

The answer of Dry air is a mixture of gases...

Question 5

Calculate the freezing point of a solution made from 22.0 g of octane (C₈H₁₈)dissolved in 248.0 g of benzene. Benzene freezes at 5.50 °C and its K_f value is 5.07 °C/m.

Accepted Answer

The answer of Calculate the freezing point of a solution...

Question 6

Arrange these aqueous solutions in order of increasing boiling points:

Accepted Answer

A)  C2H6O2 3) 2 
B)  Mg(NO3) 2 2H6O2
C)  C2H6O2 3) 2
D)  LiCl 2H6O2 3) 2
E)  Mg(NO3) 2 2H6O2 < LiCl

Question 7

Pure cyclohexane, C₆H₁₂, has a molar mass of 84.161 g mol⁻¹ and a density of0.7785 g mL⁻¹, a freezing point of 6.53°C, and a boiling point of 80.72°C. Its freezing point depression and boiling point elevation constants are: K_f = 20.0 °C m⁻¹; K_b = 2.69°C m⁻¹. A solution was made by taking 15.46 g of an unknown nonelectrolyte and dissolving it in 125.0 g of cyclohexane. The measured freezing point of the solution was -4.28°C. Calculate the molar mass of the unknown substance.Hint: Find molality, then moles, then molar mass, being sure to keep track of units.

Accepted Answer

The answer of Pure cyclohexane, C₆H₁₂, has a molar mass...

Question 8

Pure glacial acetic acid, HC₂H₃O₂, has a molar mass of 60.052 g mol⁻¹ and a density of 1.0492 g mL⁻¹, a freezing point of 16.62°C, and a boiling point of 118.3°C. Its freezing point depression and boiling point elevation constants are: K_f = 3.57 °C m⁻¹; K_b = 3.07 °C m⁻¹. A solution was made by taking 19.51 g of an unknown nonelectrolyte and dissolving it in 181.0 g of glacial acetic acid. The measured freezing point of the solution was 8.64°C. Calculate the molar mass of the unknown substance.Hint: Find molality, then moles, then molar mass, being sure to keep track of units.

Accepted Answer

The answer of Pure glacial acetic acid, HC₂H₃O₂, has a...

Question 9

What is the mole fraction of ethylene glycol, C₂H₆O₂, in an aqueous solution that is 50.0% ethylene glycol by mass?

Accepted Answer

The answer of What is the mole fraction of ethylene...

Question 10

At 28.0°C, the vapor pressure of npropyl mercaptan, C3H7SH, is 175 torr, while that of acetonitrile, CH3CN, is 102 torr. What is the vapor pressure, at 28.0°C, of a solution made by mixing 120.0 g of C3H7SH and 80.0 g CH3CN, if Raoult's Law is obeyed?Hint: Organizing the given information into moles and mole fraction of each component will help in solving this problem.

Accepted Answer

A)  131 torr
B)  135 torr
C)  142 torr
D)  146 torr
E)  277 torr

Question 11

An aqueous ethylene glycol solution being considered for use as a radiator coolant is 16.0% C2H6O2 by weight. What would be the expected boiling point of this solution? For water, Kf is 1.86 °C m-1 and Kb = 0.512 °C m?1.Hint: convert percent by mass to molality, then find $\Delta$ T.

Accepted Answer

A)  100.3°C
B)  101.6°C
C)  105.1°C
D)  106.0°C
E)  156.5°C

Question 12

How many grams of NaC2H3O2 should be dissolved in 400.0 g of water to prepare a solution that is 11.28% NaC2H3O2 by mass?

Accepted Answer

A)  3.146 g
B)  7.558 g
C)  21.17 g
D)  50.86 g
E)  127.15 g

Question 13

A solution is made by mixing 138.2 grams of ethanol, C2H6O, (46.069 g mol-1); 103.6 grams of water (18.015 g mol-1), and 80.11 grams of methanol, CH4O, (32.042 g mol-1). What is the mole fraction of methanol in the mixture?

Accepted Answer

A)  0.02504
B)  0.2222
C)  0.2493
D)  0.3333
E)  0.4490

Question 14

Pure chloroform, CHCl3, has a boiling point of 61.23°C. Its boiling point elevation constant, Kb, is 3.63°C m-1. A solution was made by taking 11.25 g of an unknown nonelectrolyte and dissolving it in 115.5 g of chloroform. The measured boiling point of the solution was 65.46°C. Calculate the molecular weight of the unknown substance.Hint: Find molality, then moles, then molar mass, being sure to keep track of units.

Accepted Answer

A)  83.6 g mol-1
B)  113 g mol-1
C)  114 g mol-1
D)  120 g mol-1
E)  158 g mol-1

Question 15

A solution contains 25.50 grams of NaNO₃ (M = 84.99 g mol⁻¹)in 250.0 grams of water. Its density is 1.0620 g mL⁻¹. Calculate the molality of the solution.

Accepted Answer

The answer of A solution contains 25.50 grams of NaNO₃...

Question 16

An aqueous solution of nitric acid has a density of 1.084 g mL-1 and a measured concentration of 2.580 molar. What is the percent by weight of nitric acid in the solution?

Accepted Answer

A)  2.380%
B)  13.82%
C)  15.00%
D)  22.29%
E)  44.38%

Question 17

Concerning the solvation step of the solution process,

Accepted Answer

A)  the process is exothermic and the potential energy increases.
B)  the process is exothermic and the potential energy decreases.
C)  the process is endothermic and the potential energy increases.
D)  the process is endothermic and the potential energy decreases.
E)  the process is endothermic and occurs with no change in potential energy.

Question 18

An aqueous solution that would cause red blood cells to burst from lowered osmotic pressure is called a(n)________ solution.

Accepted Answer

A)  hypertonic
B)  hydrophobic
C)  hypotonic
D)  asmorphic
E)  isotonic

Question 19

What is the expected freezing point of a solution that contains 25.0 g of fructose, C6H12O6, in 250.0 g of H2O? For water, Kf = 1.86 °C m-1.

Accepted Answer

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

Question 20

A solution is made by dissolving 48.07 g of MgSO₄∙7H₂O in 250.0 grams of water. What is the expected freezing point of this solution if the van't Hoff factor is 1.90? K_f = 1.86 °C m⁻¹.Hint: Don't forget to include the 7H₂O when calculating the molar mass of solute.

Accepted Answer

The answer of A solution is made by dissolving 48.07...

Exam 13: Mixtures at the Molecular Level: Properties of Solutions

When a nonvolatile solute such as ammonium sulfate is dissolved in a solvent like water, one of the observed effects is

Wax is a solid mixture of hydrocarbon compounds consisting of molecules with long chains of carbon atoms. Which solvent would you expect to be most capable of dissolving wax?

Many marine organisms that require oxygen live at ocean depths where high pressures and low temperatures would not support humans. Based on what you have learned in this chapter, what is one reason that organisms can survive under these conditions?

Calculate the freezing point of a solution made from 22.0 g of octane (C₈H₁₈)dissolved in 248.0 g of benzene. Benzene freezes at 5.50 °C and its K_f value is 5.07 °C/m.

Arrange these aqueous solutions in order of increasing boiling points:

What is the mole fraction of ethylene glycol, C₂H₆O₂, in an aqueous solution that is 50.0% ethylene glycol by mass?

An aqueous ethylene glycol solution being considered for use as a radiator coolant is 16.0% C₂H₆O₂ by weight. What would be the expected boiling point of this solution? For water, K_f is 1.86 °C m^-1 and K_b = 0.512 °C m^?1.Hint: convert percent by mass to molality, then find $\Delta$ T.

How many grams of NaC₂H₃O₂ should be dissolved in 400.0 g of water to prepare a solution that is 11.28% NaC₂H₃O₂ by mass?

A solution is made by mixing 138.2 grams of ethanol, C₂H₆O, (46.069 g mol^-1) ; 103.6 grams of water (18.015 g mol^-1) , and 80.11 grams of methanol, CH₄O, (32.042 g mol^-1) . What is the mole fraction of methanol in the mixture?

A solution contains 25.50 grams of NaNO₃ (M = 84.99 g mol⁻¹)in 250.0 grams of water. Its density is 1.0620 g mL⁻¹. Calculate the molality of the solution.

An aqueous solution of nitric acid has a density of 1.084 g mL^-1 and a measured concentration of 2.580 molar. What is the percent by weight of nitric acid in the solution?

Concerning the solvation step of the solution process,

An aqueous solution that would cause red blood cells to burst from lowered osmotic pressure is called a(n) ________ solution.

What is the expected freezing point of a solution that contains 25.0 g of fructose, C₆H₁₂O₆, in 250.0 g of H₂O? For water, K_f = 1.86 °C m^-1.

A solution is made by dissolving 48.07 g of MgSO₄∙7H₂O in 250.0 grams of water. What is the expected freezing point of this solution if the van't Hoff factor is 1.90? K_f = 1.86 °C m⁻¹.Hint: Don't forget to include the 7H₂O when calculating the molar mass of solute.

Exam 13: Mixtures at the Molecular Level: Properties of Solutions

When a nonvolatile solute such as ammonium sulfate is dissolved in a solvent like water, one of the observed effects is

Wax is a solid mixture of hydrocarbon compounds consisting of molecules with long chains of carbon atoms. Which solvent would you expect to be most capable of dissolving wax?

Many marine organisms that require oxygen live at ocean depths where high pressures and low temperatures would not support humans. Based on what you have learned in this chapter, what is one reason that organisms can survive under these conditions?

Calculate the freezing point of a solution made from 22.0 g of octane (C8H18)dissolved in 248.0 g of benzene. Benzene freezes at 5.50 °C and its Kf value is 5.07 °C/m.

Arrange these aqueous solutions in order of increasing boiling points:

What is the mole fraction of ethylene glycol, C2H6O2, in an aqueous solution that is 50.0% ethylene glycol by mass?

An aqueous ethylene glycol solution being considered for use as a radiator coolant is 16.0% C2H6O2 by weight. What would be the expected boiling point of this solution? For water, Kf is 1.86 °C m-1 and Kb = 0.512 °C m?1.Hint: convert percent by mass to molality, then find Δ\DeltaΔ T.

How many grams of NaC2H3O2 should be dissolved in 400.0 g of water to prepare a solution that is 11.28% NaC2H3O2 by mass?

A solution is made by mixing 138.2 grams of ethanol, C2H6O, (46.069 g mol-1) ; 103.6 grams of water (18.015 g mol-1) , and 80.11 grams of methanol, CH4O, (32.042 g mol-1) . What is the mole fraction of methanol in the mixture?

A solution contains 25.50 grams of NaNO3 (M = 84.99 g mol−1)in 250.0 grams of water. Its density is 1.0620 g mL−1. Calculate the molality of the solution.

An aqueous solution of nitric acid has a density of 1.084 g mL-1 and a measured concentration of 2.580 molar. What is the percent by weight of nitric acid in the solution?

Concerning the solvation step of the solution process,

An aqueous solution that would cause red blood cells to burst from lowered osmotic pressure is called a(n) ________ solution.

What is the expected freezing point of a solution that contains 25.0 g of fructose, C6H12O6, in 250.0 g of H2O? For water, Kf = 1.86 °C m-1.

A solution is made by dissolving 48.07 g of MgSO4∙7H2O in 250.0 grams of water. What is the expected freezing point of this solution if the van't Hoff factor is 1.90? Kf = 1.86 °C m−1.Hint: Don't forget to include the 7H2O when calculating the molar mass of solute.

Calculate the freezing point of a solution made from 22.0 g of octane (C₈H₁₈)dissolved in 248.0 g of benzene. Benzene freezes at 5.50 °C and its K_f value is 5.07 °C/m.

What is the mole fraction of ethylene glycol, C₂H₆O₂, in an aqueous solution that is 50.0% ethylene glycol by mass?

An aqueous ethylene glycol solution being considered for use as a radiator coolant is 16.0% C₂H₆O₂ by weight. What would be the expected boiling point of this solution? For water, K_f is 1.86 °C m^-1 and K_b = 0.512 °C m^?1.Hint: convert percent by mass to molality, then find $\Delta$ T.

How many grams of NaC₂H₃O₂ should be dissolved in 400.0 g of water to prepare a solution that is 11.28% NaC₂H₃O₂ by mass?

A solution is made by mixing 138.2 grams of ethanol, C₂H₆O, (46.069 g mol^-1) ; 103.6 grams of water (18.015 g mol^-1) , and 80.11 grams of methanol, CH₄O, (32.042 g mol^-1) . What is the mole fraction of methanol in the mixture?

A solution contains 25.50 grams of NaNO₃ (M = 84.99 g mol⁻¹)in 250.0 grams of water. Its density is 1.0620 g mL⁻¹. Calculate the molality of the solution.

An aqueous solution of nitric acid has a density of 1.084 g mL^-1 and a measured concentration of 2.580 molar. What is the percent by weight of nitric acid in the solution?

What is the expected freezing point of a solution that contains 25.0 g of fructose, C₆H₁₂O₆, in 250.0 g of H₂O? For water, K_f = 1.86 °C m^-1.

A solution is made by dissolving 48.07 g of MgSO₄∙7H₂O in 250.0 grams of water. What is the expected freezing point of this solution if the van't Hoff factor is 1.90? K_f = 1.86 °C m⁻¹.Hint: Don't forget to include the 7H₂O when calculating the molar mass of solute.