Question 1

Choose the situation below that would result in an endothermic ΔsolutionH.

Accepted Answer

A) when   >   
B) when      
E) There isn't enough information to determine the answer. 
A) when   >   
B) when      
E) There isn't enough information to determine the answer. A

Question 2

The Henry's law constant for helium gas in water at 30 °C is 3.70 × 10-4 mol L-1 bar-1. When the partial pressure of helium above a sample of water is 0.650 bar, the concentration of helium in the water is ________ mol L-1.

Accepted Answer

A) 5.69 × 10-4 
B) 1.76 × 103 
C) 1.30 
D) 2.41 × 10-4 
E) 3.70 × 10-4 
A) 5.69 × 10-4 
B) 1.76 × 103 
C) 1.30 
D) 2.41 × 10-4 
E) 3.70 × 10-4 D

Question 3

A mixture of chloroform and acetone has a vapour pressure of 311 Torr. Calculate the mole fraction of acetone in the mixture. The vapour pressures of chloroform and acetone are 295 Torr and 332 Torr, respectively. Assume ideal behaviour.

Accepted Answer

A) 0.432 
B) 0.730 
C) 0.270 
D) 0.619 
E) 0.568 
A) 0.432 
B) 0.730 
C) 0.270 
D) 0.619 
E) 0.568 A

Question 4

Calculate the solution temperature required to produce an osmotic pressure of 1.10 mbar using 3.85 mg of a protein with a molar mass of 4183 g mol-1 that is dissolved in enough water to create 20.0 mL of solution.

Accepted Answer

A) 288 K 
B) 293 K 
C) 278 K 
D) 314 K 
E) 299 K 
A) 288 K 
B) 293 K 
C) 278 K 
D) 314 K 
E) 299 K

Question 5

Solutions having osmotic pressures less than those of body fluids are called ________.

Accepted Answer

A) isosmotic 
B) hyperosmotic 
C) hyposmotic 
D) neosmotic 
E) magnosmotic 
A) isosmotic 
B) hyperosmotic 
C) hyposmotic 
D) neosmotic 
E) magnosmotic

Question 6

A 4.55 L sample of water contains 0.115 g of sodium ions. Determine the concentration of sodium ions in ppm if the density of the solution is 1.00 g mL-1.

Accepted Answer

A) 52.3 ppm 
B) 13.2 ppm 
C) 12.7 ppm 
D) 25.3 ppm 
E) 36.5 ppm 
A) 52.3 ppm 
B) 13.2 ppm 
C) 12.7 ppm 
D) 25.3 ppm 
E) 36.5 ppm

Question 7

Which of the following statements is generally TRUE?

Accepted Answer

A) The solubility of a solid is not dependent on either temperature or pressure. 
B) The solubility of a solid is highly dependent on pressure. 
C) The solubility of a solid is highly dependent on both pressure and temperature. 
D) The solubility of a solid is highly dependent on temperature. 
E) None of the above 
A) The solubility of a solid is not dependent on either temperature or pressure. 
B) The solubility of a solid is highly dependent on pressure. 
C) The solubility of a solid is highly dependent on both pressure and temperature. 
D) The solubility of a solid is highly dependent on temperature. 
E) None of the above

Question 8

Give the reason that antifreeze is added to a car radiator.

Accepted Answer

A) The freezing point is lowered and the boiling point is elevated. 
B) The freezing point is elevated and the boiling point is lowered. 
C) The freezing point and the boiling point are elevated. 
D) The freezing point and the boiling point are lowered. 
E) None of the above. 
A) The freezing point is lowered and the boiling point is elevated. 
B) The freezing point is elevated and the boiling point is lowered. 
C) The freezing point and the boiling point are elevated. 
D) The freezing point and the boiling point are lowered. 
E) None of the above.

Question 9

Calculate the freezing point of a solution of 40.0 g methyl salicylate, C7H6O2, dissolved in 800. g of benzene, C6H6. Kf for benzene is 5.10 °C m-1 and the freezing point is 5.50 °C for benzene.

Accepted Answer

A) -2.09 °C 
B) 2.09 °C 
C) 3.41 °C 
D) 7.59 °C 
A) -2.09 °C 
B) 2.09 °C 
C) 3.41 °C 
D) 7.59 °C

Question 10

At 20 °C, a 2.32 mol L-1 aqueous solution of ammonium chloride has a density of 1.0344 g mL-1. What is the molality of ammonium chloride in the solution? The formula weight of NH4Cl is 53.50 g mol-1.

Accepted Answer

A) 2.55 
B) 0.0449 
C) 2.32 
D) 0.446 
E) 12.00 
A) 2.55 
B) 0.0449 
C) 2.32 
D) 0.446 
E) 12.00

Question 11

Define smoke as a colloid.

Accepted Answer

A) a liquid dispersed in a gas 
B) a solid dispersed in a gas 
C) a liquid dispersed in a liquid 
D) a liquid dispersed in a solid 
E) a solid dispersed in a liquid 
A) a liquid dispersed in a gas 
B) a solid dispersed in a gas 
C) a liquid dispersed in a liquid 
D) a liquid dispersed in a solid 
E) a solid dispersed in a liquid

Question 12

What is the mole fraction of ethanol in a solution made by dissolving 29.2 g of ethanol, C2H5OH, in 53.6 g of water?

Accepted Answer

A) 0.176 
B) 0.213 
C) 0.352 
D) 0.545 
A) 0.176 
B) 0.213 
C) 0.352 
D) 0.545

Question 13

Fluids used for an intravenous transfusion must be ________ with bodily fluids.

Accepted Answer

A) isosmotic 
B) hyperosmotic 
C) hyposmotic 
D) neosmotic 
E) magnosmotic 
A) isosmotic 
B) hyperosmotic 
C) hyposmotic 
D) neosmotic 
E) magnosmotic

Question 14

Which of the following should have the largest Henry's law constant (kH)in water?

Accepted Answer

A) Ar 
B) CO 
C) Xe 
D) CH3CH3 
E) CO2 
A) Ar 
B) CO 
C) Xe 
D) CH3CH3 
E) CO2

Question 15

Identify the classification of opal.

Accepted Answer

A) aerosol 
B) solid aerosol 
C) foam 
D) emulsion 
E) solid emulsion 
A) aerosol 
B) solid aerosol 
C) foam 
D) emulsion 
E) solid emulsion

Question 16

Choose the aqueous solution below with the highest freezing point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

Accepted Answer

A) 0.200 mol kg-1 Ca(ClO4)2 
B) 0.200 mol kg-1 K3PO3 
C) 0.200 mol kg-1 HOCH2CH2OH 
D) 0.200 mol kg-1 Ba(NO3)2 
E) These all have the same freezing point. 
A) 0.200 mol kg-1 Ca(ClO4)2 
B) 0.200 mol kg-1 K3PO3 
C) 0.200 mol kg-1 HOCH2CH2OH 
D) 0.200 mol kg-1 Ba(NO3)2 
E) These all have the same freezing point.

Question 17

Identify the major force between ethanol and water.

Accepted Answer

A) dipole-dipole 
B) dispersion 
C) hydrogen bonding 
D) ion-ion 
E) ion-dipole 
A) dipole-dipole 
B) dispersion 
C) hydrogen bonding 
D) ion-ion 
E) ion-dipole

Question 18

A solution is 0.0433 mol kg-1 LiF. What is the molarity of the solution if the density is 1.10 g mL-1?

Accepted Answer

A) 0.0441 mol L-1 
B) 0.0390 mol L-1 
C) 0.0519 mol L-1 
D) 0.0476 mol L-1 
E) 0.0417 mol L-1 
A) 0.0441 mol L-1 
B) 0.0390 mol L-1 
C) 0.0519 mol L-1 
D) 0.0476 mol L-1 
E) 0.0417 mol L-1

Question 19

At a given temperature the vapour pressures of benzene and toluene are 183 mmHg and 59.2 mmHg, respectively. Calculate the total vapour pressure over a solution of benzene and toluene with Xbenzene = 0.580.

Accepted Answer

A) 106 mmHg 
B) 121 mmHg 
C) 131 mmHg 
D) 242 mmHg 
A) 106 mmHg 
B) 121 mmHg 
C) 131 mmHg 
D) 242 mmHg

Question 20

Four times as much pentane (C5H12)by mass is mixed with hexane (C6H14). Calculate the vapour pressure of the resulting solution. The vapour pressures of pure pentane and hexane are 425 Torr and 151 Torr, respectively. Assume ideal behaviour.

Accepted Answer

A) 214 Torr 
B) 378 Torr 
C) 385 Torr 
D) 203 Torr 
E) 365 Torr 
A) 214 Torr 
B) 378 Torr 
C) 385 Torr 
D) 203 Torr 
E) 365 Torr

Exam 12: Solutions

Choose the situation below that would result in an endothermic ΔsolutionH.

The Henry's law constant for helium gas in water at 30 °C is 3.70 × 10-4 mol L-1 bar-1. When the partial pressure of helium above a sample of water is 0.650 bar, the concentration of helium in the water is ________ mol L-1.

A mixture of chloroform and acetone has a vapour pressure of 311 Torr. Calculate the mole fraction of acetone in the mixture. The vapour pressures of chloroform and acetone are 295 Torr and 332 Torr, respectively. Assume ideal behaviour.

Calculate the solution temperature required to produce an osmotic pressure of 1.10 mbar using 3.85 mg of a protein with a molar mass of 4183 g mol-1 that is dissolved in enough water to create 20.0 mL of solution.

Solutions having osmotic pressures less than those of body fluids are called ________.

A 4.55 L sample of water contains 0.115 g of sodium ions. Determine the concentration of sodium ions in ppm if the density of the solution is 1.00 g mL-1.

Which of the following statements is generally TRUE?

Give the reason that antifreeze is added to a car radiator.

Calculate the freezing point of a solution of 40.0 g methyl salicylate, C7H6O2, dissolved in 800. g of benzene, C6H6. Kf for benzene is 5.10 °C m-1 and the freezing point is 5.50 °C for benzene.

At 20 °C, a 2.32 mol L-1 aqueous solution of ammonium chloride has a density of 1.0344 g mL-1. What is the molality of ammonium chloride in the solution? The formula weight of NH4Cl is 53.50 g mol-1.

Define smoke as a colloid.

What is the mole fraction of ethanol in a solution made by dissolving 29.2 g of ethanol, C2H5OH, in 53.6 g of water?

Fluids used for an intravenous transfusion must be ________ with bodily fluids.

Which of the following should have the largest Henry's law constant (kH)in water?

Identify the classification of opal.

Choose the aqueous solution below with the highest freezing point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.

Identify the major force between ethanol and water.

A solution is 0.0433 mol kg-1 LiF. What is the molarity of the solution if the density is 1.10 g mL-1?

At a given temperature the vapour pressures of benzene and toluene are 183 mmHg and 59.2 mmHg, respectively. Calculate the total vapour pressure over a solution of benzene and toluene with Xbenzene = 0.580.

Four times as much pentane (C5H12)by mass is mixed with hexane (C6H14). Calculate the vapour pressure of the resulting solution. The vapour pressures of pure pentane and hexane are 425 Torr and 151 Torr, respectively. Assume ideal behaviour.

Units of Measurement for Physical and Chemical Change

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Chemical Reactions and Stoichiometry

Gases

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The Quantum-Mechanical Model of the Atom

Periodic Properties of the Elements

Chemical Bonding I: Lewis Theory

Chemical Bonding Ii: Molecular Shapes, Valence Bond Theory, and Molecular Orbital Theory

Liquids, Solids, and Intermolecular Forces

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Radioactivity and Nuclear Chemistry

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Organic Chemistry II: Reactions

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Chemistry of the Nonmetals

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Filters

Choose the situation below that would result in an endothermic Δ_solutionH.

The Henry's law constant for helium gas in water at 30 °C is 3.70 × 10^-4 mol L^-1 bar^-1. When the partial pressure of helium above a sample of water is 0.650 bar, the concentration of helium in the water is ________ mol L^-1.

Calculate the solution temperature required to produce an osmotic pressure of 1.10 mbar using 3.85 mg of a protein with a molar mass of 4183 g mol^-1 that is dissolved in enough water to create 20.0 mL of solution.

A 4.55 L sample of water contains 0.115 g of sodium ions. Determine the concentration of sodium ions in ppm if the density of the solution is 1.00 g mL^-1.

Calculate the freezing point of a solution of 40.0 g methyl salicylate, C₇H₆O₂, dissolved in 800. g of benzene, C₆H₆. K_f for benzene is 5.10 °C m^-1 and the freezing point is 5.50 °C for benzene.

At 20 °C, a 2.32 mol L^-1 aqueous solution of ammonium chloride has a density of 1.0344 g mL^-1. What is the molality of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g mol^-1.

What is the mole fraction of ethanol in a solution made by dissolving 29.2 g of ethanol, C₂H₅OH, in 53.6 g of water?

Which of the following should have the largest Henry's law constant (k_H)in water?

A solution is 0.0433 mol kg^-1 LiF. What is the molarity of the solution if the density is 1.10 g mL^-1?

At a given temperature the vapour pressures of benzene and toluene are 183 mmHg and 59.2 mmHg, respectively. Calculate the total vapour pressure over a solution of benzene and toluene with X_benzene = 0.580.

Four times as much pentane (C₅H₁₂)by mass is mixed with hexane (C₆H₁₄). Calculate the vapour pressure of the resulting solution. The vapour pressures of pure pentane and hexane are 425 Torr and 151 Torr, respectively. Assume ideal behaviour.