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Chapter 12 - Solutions

1. Which of the following concerning solutions is/are correct?

1. The solvent in a mixture of gases is generally considered to be the substance in greater amount.

2. The solid dissolved in a solution is known as the solute.3. Solid solutions are called alloys.

A) 1 onlyB) 2 onlyC) 3 onlyD) 1 and 2E) 1, 2, and 3

ANS: E PTS: 1 DIF: easy REF: 12.1OBJ: Types of Solutions TOP: solutions | solution formation

2. Which of the following concerning solutions is/are correct?

1. For a solution to form, the solvent and solute must be miscible.2. A solution may be homogeneous or heterogeneous.3. A colloid is a type of solution.


ANS: A PTS: 1 DIF: easy REF: 12.1OBJ: Types of Solutions TOP: solutions | solution formation

3. Suppose a small amount of a solid is added to water and, after a short time, all the solid has dissolved. Which of the following statements is most likely to be true?A) The solution is supersaturated with solute.B) The solution is saturated with solute.C) The solution is unsaturated with solute.D) The solution is either unsaturated or supersaturated with solute.E) The solution is either saturated or supersaturated with solute.

ANS: C PTS: 1 DIF: easy REF: 12.2OBJ: List the conditions that must be present to have a saturated solution, to have an unsaturated solution, and to have a supersaturated solution.TOP: solutions | solution formation KEY: solubility | saturated solutionMSC: general chemistry

Test Bank General Chemistry, 10th edition 1

4. Which of the following concerning solubility and the solution process is/are correct?

1. In a saturated solution of a substance, a solution of the substance is in equilibrium with the pure substance.

2. Dissolution of a solute stops once saturation of a solvent is achieved.3. Solubility depends in part on the strength of solute-solute and solute-solvent

Van der Waals forces.


ANS: D PTS: 1 DIF: easy REF: 12.2OBJ: List the conditions that must be present to have a saturated solution, to have an unsaturated solution, and to have a supersaturated solution.TOP: solutions | solution formation

5. Which of the following concerning solubility and the solution process is/are correct?

1. Both hydration energies and lattice energies depend on the magnitude of the ion charges and the size of the ions.

2. An initially nonhomogeneous mixture of two miscible liquids, given enough time, will eventually form a solution as a result of random molecular motions.

3. The dissolution of ionic compounds in water depends only on the hydration energy of the ions.


ANS: D PTS: 1 DIF: easy REF: 12.2OBJ: List the conditions that must be present to have a saturated solution, to have an unsaturated solution, and to have a supersaturated solution.TOP: solutions | solution formation

6. Which of the following sets of conditions favors maximum solubility of solute in solvent?A) The intermolecular forces between solute and solvent molecules are much weaker

than the intermolecular forces between solute molecules, but much stronger than the intermolecular forces between solvent molecules.

B) The intermolecular forces between solute and solvent molecules are much stronger than the intermolecular forces between solute molecules or the intermolecular forces between solvent molecules.

C) The intermolecular forces between solute and solvent molecules are much stronger than the intermolecular forces between solvent molecules, but much weaker than the intermolecular forces between solute molecules.


D) The intermolecular forces between solute and solvent molecules are much stronger than the intermolecular forces between solute molecules, but much weaker than the intermolecular forces between solvent molecules.

E) The intermolecular forces between solute and solvent molecules are much weaker than the intermolecular forces between solute molecules or the intermolecular forces between solvent molecules.

ANS: B PTS: 1 DIF: easy REF: 12.2OBJ: Describe the factors that make one substance soluble in another.TOP: solutions | solution formation KEY: solubility MSC: general chemistry

7. In general, which of the following type(s) of solid(s) would exhibit the greatest solubility in a nonpolar solvent?

A) network covalentB) nonpolar molecularC) ionicD) metallicE) polar molecular

ANS: B PTS: 1 DIF: easy REF: 12.2OBJ: Describe the factors that make one substance soluble in another.TOP: solutions | solution formation

8. Which of the following gases is least soluble in water?A) CO2

B) SO3

C) NH3

D) N2

E) HCl

ANS: D PTS: 1 DIF: easy REF: 12.2OBJ: Determine when a molecular solution will form when substances are mixed.TOP: solutions | solution formation KEY: solubility | molecular solutionMSC: general chemistry

9. Which of the following pure liquids is the best solvent for sodium fluoride?A) CCl4(l)B) C2Cl6(l)C) HCl(l)D) BCl3(l)E) PCl5(l)

ANS: C PTS: 1 DIF: easy REF: 12.2OBJ: Determine when a molecular solution will form when substances are mixed.TOP: solutions | solution formation KEY: solubility | ionic solutionMSC: general chemistry


10. Which of the following pure liquids is the best solvent for carbon disulfide?A) C6H6(l)B) NH3(l)C) CH3OH(l)D) H2O(l)E) HBr(l)

ANS: A PTS: 1 DIF: easy REF: 12.2OBJ: Determine when a molecular solution will form when substances are mixed.TOP: solutions | solution formation KEY: solubility | molecular solutionMSC: general chemistry

11. Which of the following compounds is least soluble in water?A) CH3CH2CH2NH2

B) CH3CH2CH2FC) CH3CH(OH)CH3

D) CH3CH2COOHE) CH3CH2NHCH3

ANS: B PTS: 1 DIF: easy REF: 12.2OBJ: Determine when a molecular solution will form when substances are mixed.TOP: solutions | solution formation KEY: solubility | molecular solutionMSC: general chemistry

12. The solubility of 1-hexanol in water is 0.60 g per 100 g of water at 25°C. What is the maximum amount of 1-hexanol that will dissolve in 5.3 g of water at 25°C?A) 0.032 gB) 0.11 gC) 0.60 gD) 3.2 gE) 0.0011 g

ANS: A PTS: 1 DIF: easy REF: 12.2OBJ: Determine when a molecular solution will form when substances are mixed.TOP: solutions | solution formation KEY: solubility | molecular solutionMSC: general chemistry

13. Which of the following sets of conditions favors maximum solubility of an ionic solute in water?A) The enthalpy of hydration of the cation should be equal to the enthalpy of

hydration of the anion, regardless of the magnitude of the lattice energy.B) The magnitude of the lattice energy should be small, and the enthalpy of hydration

of the ions should be large.C) The magnitude of the lattice energy should be small, and the enthalpy of hydration

of the ions should be small.D) The magnitude of the lattice energy should be large, and the enthalpy of hydration

of the ions should be small.E) The magnitude of the lattice energy should be large, and the enthalpy of hydration

of the ions should be large.


ANS: B PTS: 1 DIF: easy REF: 12.2OBJ: Learn what conditions must be met in order to create an ionic solution.TOP: solutions | solution formation KEY: solubility | ionic solutionMSC: general chemistry

14. Which of the following favor(s) the solubility of an ionic solid in a liquid solvent?A) a small magnitude of the lattice energy of the soluteB) a large magnitude of the solvation energy of the ionsC) a large polarity of the solventD) all of the aboveE) none of the above

ANS: D PTS: 1 DIF: easy REF: 12.2OBJ: Learn what conditions must be met in order to create an ionic solution.TOP: solutions | solution formation KEY: solubility | ionic solutionMSC: general chemistry

15. Which of the following statements best describes what happens when a small amount of solid rubidium bromide is dissolved in water?A) The heat from the warm water melts the solid, making it a liquid.B) Nothing happens, because rubidium bromide is insoluble in water.C) The solid RbBr breaks apart into separate Rb and Br atoms by interacting with the

water molecules.D) The water molecules surround each ion in the solid RbBr, separating the Rb ions

from the Br ions.E) The solid undergoes a chemical change by reacting with the water.

ANS: D PTS: 1 DIF: easy REF: 12.2OBJ: Learn what conditions must be met in order to create an ionic solution.TOP: solutions | solution formation KEY: solubility | ionic solutionMSC: general chemistry

16. Which of the following correctly states the relationship between the solubility of a substance in water and temperature?A) The solubility of a substance in water increases as the temperature rises, especially

for gases.B) The solubility of a substance in water decreases as the temperature lowers,

especially for gases.C) The relationship between the solubility of a substance in water and temperature

cannot be accurately predicted, especially for ionic solids.D) The solubility of a substance in water decreases as the temperature rises, especially

for ionic solids.E) Two of these are correct.

ANS: C PTS: 1 DIF: easy REF: 12.3OBJ: State the general trends of the solubility of gases and solids with temperature.TOP: solutions | solution formationKEY: effect of temperature and pressure on solubility | temperature changeMSC: general chemistry


17. Which of the following concerning the effects of temperature and pressure on solubility is/are correct?

1. All gases become more soluble in a liquid at a fixed pressure when the temperature of the liquid is increased.

2. The dissolution of an ionic compound in water may be exothermic or endothermic, depending on the initial temperature of the solution.

3. The solubility of a liquid in water generally is significantly effected by pressure changes of the system.

A) 1 onlyB) 2 onlyC) 3 onlyD) 1 and 2E) none

ANS: E PTS: 1 DIF: easy REF: 12.3OBJ: State the general trends of the solubility of gases and solids with temperature.TOP: solutions | solution formation

18. Consider the following gas-aqueous liquid equilibrium for a closed system at a constant temperature.

O2(g) O2(aq)

What is the effect on the equilibrium composition of the liquid when the partial pressure of O2 gas above the liquid is increased?

A) The amount of O2 dissolved in the liquid increases.B) The amount of O2 dissolved in the liquid decreases.C) The amount of O2 dissolved in the liquid does not change.D) Not enough information is provided to answer the question.E) Either A or B.

ANS: A PTS: 1 DIF: easy REF: 12.3OBJ: State the general trends of the solubility of gases and solids with temperature.TOP: solutions | solution formation

19. Consider the following gas-liquid equilibrium for an aqueous system at a constant partial pressure of N2.

N2(g) N2(aq)

What is the effect on the equilibrium composition of the liquid when the temperature of the liquid is increased?


A) The amount of N2 dissolved in the liquid increases.B) The amount of N2 dissolved in the liquid decreases.C) The amount of N2 dissolved in the liquid does not change.D) Not enough information is provided to answer the question.E) Either A or B could occur.

ANS: B PTS: 1 DIF: easy REF: 12.3OBJ: State the general trends of the solubility of gases and solids with temperature.TOP: solutions | solution formation

20. Which of the following affect(s) the solubility of gases in solvents?1. the nature of the gas2. the nature of the solvent3. the temperature of the solvent


ANS: E PTS: 1 DIF: easy REF: 12.3OBJ: State the general trends of the solubility of gases and solids with temperature.TOP: solutions | solution formationKEY: effect of temperature and pressure on solubility | temperature changeMSC: general chemistry

21. How does the solubility of a gas in a solvent depend on pressure and temperature?A) Increasing the partial pressure of the gas while increasing the temperature

increases the solubility of the gas.B) Decreasing the partial pressure of the gas while decreasing the temperature

increases the solubility of the gas.C) Increasing the partial pressure of the gas while decreasing the temperature

increases the solubility of the gas.D) Decreasing the partial pressure of the gas while increasing the temperature

increases the solubility of the gas.E) Gas solubility is unaffected by pressure or temperature.

ANS: C PTS: 1 DIF: easy REF: 12.3OBJ: Explain how the solubility of a gas changes with temperature.TOP: solutions | solution formationKEY: effect of temperature and pressure on solubility MSC: general chemistry


22. Which of the following is a correct statement of Henry's law?A) The concentration of a gas in solution is directly proportional to the mole fraction

of solvent.B) The concentration of a gas in solution is inversely proportional to temperature.C) The concentration of a gas in solution is independent of pressure.D) The concentration of a gas in a solution is inversely proportional to pressure.E) none of these

ANS: E PTS: 1 DIF: easy REF: 12.3OBJ: Apply Henry’s law. (Example 12.1)TOP: solutions | solution formationKEY: effect of temperature and pressure on solubility | Henry's lawMSC: general chemistry

23. The solubility of a gas in a liquid can always be increased byA) decreasing the pressure of the gas above the solvent.B) increasing the pressure of the gas above the solvent.C) increasing the temperature of the solvent.D) decreasing the polarity of the solvent.E) decreasing the temperature of the gas above the solvent.

ANS: B PTS: 1 DIF: easy REF: 12.3OBJ: Apply Henry’s law. (Example 12.1)TOP: solutions | solution formationKEY: effect of temperature and pressure on solubility | pressure changeMSC: general chemistry

24. At a particular temperature the solubility of O2 in water is 0.590 g/L at an oxygen pressure of around 14.7 atm. What is the Henry's law constant for O2 (in units of L · atm/mol)?A) 4.01 10-2

B) 7.97 102

C) 2.71 10-1

D) 1.25 10-3

E) None of the above are within 5% of the correct answer.

ANS: B PTS: 1 DIF: moderate REF: 12.3OBJ: Apply Henry’s law. (Example 12.1)TOP: solutions | solution formationKEY: effect of temperature and pressure on solubility | Henry's lawMSC: general chemistry


25. According to the National Institute of Standards webbook, the Henry’s Law constant for N2 gas is 0.00060 mol/kgbar at 25C What is the Henry's law constant in units of mol/kgatm? (1 bar = 0.9869 atm; 1 atm = 760 mmHg)

A) 6.1 10 4 mol/kgatmB) 8.0 10 7 mol/kgatmC) 4.6 10 1 mol/kgatmD) 1.6 103 mol/kgatmE) 1.3 106 mol/kgatm

ANS: A PTS: 1 DIF: easy REF: 12.3OBJ: Apply Henry’s law. (Example 12.1)TOP: solutions | solution formation

26. Henry’s Law constant is 0.00060 mol/kgbar and 0.0013 mol/kgbar for N2 and O2 respectively at 25C. What pressure of O2 is required to achieve the same solubility as 0.616 bar of N2?

A) 0.28 barB) 1.3 barC) 4.8 10 7 barD) 1.3 10 6 barE) 3.5 bar

ANS: A PTS: 1 DIF: easy REF: 12.3OBJ: Apply Henry’s law. (Example 12.1)TOP: solutions | solution formation

27. If the solubility of O2 at 0.360 bar and 25C is 15.0 g/100 g H2O, what is the solubility of O2 at a pressure of 1.72 bar and 25C?

A) 71.7 g/100 g H2O B) 24.2 g/100 g H2OC) 0.319 g/100 g H2OD) 0.0140 g/100 g H2OE) 3.14 g/100 g H2O

ANS: A PTS: 1 DIF: moderate REF: 12.3OBJ: Apply Henry’s law. (Example 12.1)TOP: solutions | solution formation

28. Which of the following is not a colligative property?

A) boiling-point elevationB) osmotic pressureC) gas solubilityD) freezing-point loweringE) vapor-pressure lowering


ANS: C PTS: 1 DIF: easy REF: 12.4OBJ: Define colligative property. TOP: solutions | colligative properties

29. As the number of solute particles in a given volume of solution increases,A) the boiling point will increase and the vapor pressure will increase.B) the freezing point will decrease and the vapor pressure will decrease.C) the freezing point will increase and the vapor pressure will increase.D) the boiling point will decrease and the vapor pressure will decrease.E) the osmotic pressure will decrease and the lattice energy will increase.

ANS: B PTS: 1 DIF: moderate REF: 12.4OBJ: Define colligative property. TOP: solutions | colligative propertiesMSC: general chemistry

30. The molarity of a solution is defined as theA) moles of solute per liter of solvent.B) grams of solute per kilogram of solvent.C) grams of solute per liter of solution.D) moles of solute per liter of solution.E) moles of solute per kilogram of solvent.

ANS: D PTS: 1 DIF: easy REF: 12.4OBJ: Define molarity. TOP: solutions | colligative propertiesKEY: expressing concentration MSC: general chemistry

31. The molarity of a solution is defined as theA) moles of solute per liter of solvent.B) moles of solute per kilogram of solution.C) moles of solute per mole of solution.D) moles of solute per kilogram of solvent.E) moles of solute per liter of solution.

ANS: E PTS: 1 DIF: easy REF: 12.4OBJ: Define molarity. TOP: solutions | colligative propertiesKEY: expressing concentration MSC: general chemistry

32. The molality of a solution is defined asA) moles of solute per liter of solution.B) the gram molecular weight of solute per kilogram of solvent.C) moles of solute per kilogram of solvent.D) grams of solute per liter of solution.E) moles of solute per kilogram of solution.

ANS: C PTS: 1 DIF: easy REF: 12.4OBJ: Define molality. TOP: solutions | colligative propertiesKEY: expressing concentration | molality MSC: general chemistry


33. Which of the following concerning the topic of concentration is/are correct?

1. A concentrated solution of hydrochloric acid has a molarity of 12 M. This means that 12 moles of HCl are dissolved in 1.0 L of water.

2. The molality of a solution is unaffected by changes in temperature, even though the total volume of the solution may change significantly.

3. When calculating a mass percent, the “mass of solution” is equal to the sum of the masses of all solution components.


ANS: D PTS: 1 DIF: easy REF: 12.4OBJ: Define all concentration units. TOP: solutions | colligative properties

34. Which of the following concerning the topic of concentration is/are correct?

1. A 5.0 molal HCl solution consists of 5.5 moles HCl dissolved in 1.0 kg of solution.

2. The mass percent and mole percent of a particular component in a solution are identical.

3. The mole fraction of a component in a solution may never be greater than 1.

A) 1 onlyB) 2 onlyC) 3 onlyD) 1 and 2E) none of the above

ANS: C PTS: 1 DIF: easy REF: 12.4OBJ: Define all concentration units. TOP: solutions | colligative properties

35. What mass of an aqueous 22.9% sodium chloride solution contains 99.5 g of water?

A) 129 gB) 29.6 gC) 0.500 gD) 22.8 gE) 99.5 g

ANS: A PTS: 1 DIF: easy REF: 12.4OBJ: Calculate mass percentage of solute. (Example 12.2)TOP: solutions | colligative properties


36. What is the mass of H2SO4 in a 49.5-cm3 sample of concentrated sulfuric acid that has a density of 1.84 g/cm3 and consists of 98.3% H2SO4?A) 48.7 gB) 89.5 gC) 3.65 gD) 1.81 gE) 26.4 g

ANS: B PTS: 1 DIF: easy REF: 12.4OBJ: Calculate mass percentage of solute. (Example 12.2)TOP: solutions | colligative propertiesKEY: expressing concentration | mass percentage of solute MSC: general chemistry

37. A concentrated sulfuric acid solution is 65.0% H2SO4 by mass and has a density of 1.55 g/mL at 20°C. What is the mass of 3.00 L of the concentrated sulfuric acid solution?A) 1.95 kgB) 3.00 kgC) 7.15 kgD) 1.26 kgE) 4.65 kg

ANS: E PTS: 1 DIF: easy REF: 12.4OBJ: Calculate mass percentage of solute. (Example 12.2)TOP: solutions | colligative propertiesKEY: expressing concentration | mass percentage of solute MSC: general chemistry

38. A concentrated potassium hydroxide solution is 45.0% KOH by mass and has a density of 1.44 g/mL at 25°C. What is the mass of KOH per L of solution?

A) 648 g KOH/L solnB) 0.00144 g KOH/L solnC) 313 g KOH/L solnD) 0.320 g KOH/L solnE) 3.13 g KOH/L soln


39. A concentrated phosphoric acid solution is 85.5% H3PO4 by mass and has a density of 1.69 g/mL at 25°C. What is the molarity of H3PO4?

A) 14.7 MB) 0.166 MC) 5.16 MD) 19.4 ME) 0.0516 M



40. A concentrated perchloric acid solution has a density of 1.67 g/mL at 25°C and is 11.7 M. What is the percent by mass of HClO4 in the solution?

A) 70.4% HClO4 by massB) 0.702% HClO4 by massC) 1.42% HClO4 by massD) 0.699% HClO4 by massE) 60.2% HClO4 by mass


41. What is the mass percent of an aqueous sodium hydroxide solution in which the mole fraction of NaOH is 0.231? The density of the solution is 1.4339 g/mL.A) 40.0%B) 6.21%C) 68.9%D) 33.1%E) 6.44%

ANS: A PTS: 1 DIF: difficult REF: 12.4OBJ: Calculate mass percentage of solute. (Example 12.2)TOP: solutions | colligative propertiesKEY: expressing concentration | conversion of concentration unitsMSC: general chemistry

42. What is the mass percent of an aqueous sodium hydroxide solution in which the molarity of NaOH is 4.37 M? The density of the solution is 1.1655 g/mL.A) 0.267%B) 15.0%C) 5.09%D) 1.53%E) 68.9%

ANS: B PTS: 1 DIF: difficult REF: 12.4OBJ: Calculate mass percentage of solute. (Example 12.2)TOP: solutions | colligative propertiesKEY: expressing concentration | conversion of concentration unitsMSC: general chemistry

43. What is the mass percent of an aqueous sodium hydroxide solution in which the molality of NaOH is 25.0 m? The density of the solution is 1.5290 g/mL.A) 0.0612%B) 68.9%C) 1.76%D) 50.0%E) 0.654%


ANS: D PTS: 1 DIF: difficult REF: 12.4OBJ: Calculate mass percentage of solute. (Example 12.2)TOP: solutions | colligative propertiesKEY: expressing concentration | conversion of concentration unitsMSC: general chemistry

44. The mass of a 12.0% (by mass) solution is 8.82 g. The density of the solution is 1.120 g/mL. What is the mass of the water in this solution?A) 7.76 gB) 10 gC) 1.19 gD) 0.00774 gE) 8.69 g

ANS: A PTS: 1 DIF: easy REF: 12.4OBJ: Calculate mass percentage of solute. (Example 12.2)TOP: solutions | colligative propertiesKEY: expressing concentration | mass percentage of solute MSC: general chemistry

45. The volume of a 14.4% (by mass) solution is 67.0 mL. The density of the solution is 1.072 g/mL. What is the mass of the solution?A) 71.8 gB) 62.5 gC) 1030 gD) 103 gE) 10.3 g


46. The volume of a 15.8% (by mass) solution is 146.4 mL. The density of the solution is 1.084 g/mL. What is the mass of solute in this solution?A) 159 gB) 25.1 gC) 1004 gD) 21.3 gE) 134 g



47. What is the molarity of a 20.0% by mass hydrochloric acid solution? The density of the solution is 1.0980 g/mL.A) 6.86 MB) 0.200 MC) 5.68 MD) 6.02 ME) 0.0220 M

ANS: D PTS: 1 DIF: moderate REF: 12.4OBJ: Calculate mass percentage of solute. (Example 12.2)TOP: solutions | colligative propertiesKEY: expressing concentration | conversion of concentration unitsMSC: general chemistry

48. What mass of a 26.0% by mass glucose, C6H12O6, solution contains 42.0 g of glucose?A) 46.8 gB) 162 gC) 10.9 gD) 60.7 gE) 42.0 g


49. What is the percent Na2CO3 by mass in a 1.54 molal aqueous solution?A) 0.132%B) 14.0%C) 99.4%D) 16.3%E) 15.4%

ANS: B PTS: 1 DIF: easy REF: 12.4OBJ: Calculate mass percentage of solute. (Example 12.2)TOP: solutions | colligative propertiesKEY: expressing concentration | conversion of concentration unitsMSC: general chemistry

50. What mass of a solution labeled 6.3% sucrose (C12H22O11, 342 g/mol) by mass contains 15.0 g of sucrose?A) 3.4 gB) 39 gC) 240 gD) 0.28 gE) 95 g

ANS: C PTS: 1 DIF: easy REF: 12.4OBJ: Calculate mass percentage of solute. (Example 12.2)TOP: solutions | colligative propertiesKEY: expressing concentration | mass percentage of solute MSC: general chemistry


51. A 12.0% sucrose solution by mass has a density of 1.05 g/cm3. What mass of sucrose is present in a 30.0-mL sample of this solution?A) 3.78 gB) 3.43 gC) 0.126 gD) 263 gE) 3.60 g


52. How many moles of urea (60. g/mol) must be dissolved in 77.6 g of water to give a 3.5 m solution?A) 2.1 102 molB) 3.5 molC) 0.0035 molD) 0.27 molE) 7.7 102 mol

ANS: D PTS: 1 DIF: easy REF: 12.4OBJ: Calculate the molality of solute. (Example 12.3)TOP: solutions | colligative properties KEY: expressing concentration | molalityMSC: general chemistry

53. If 12.7 g of naphthalene, C10H8, is dissolved in 104.6 g of chloroform, CHCl3, what is the molality of the solution?A) 0.0992 mB) 14.5 mC) 0.949 mD) 0.108 mE) 0.113 m

ANS: C PTS: 1 DIF: easy REF: 12.4OBJ: Calculate the molality of solute. (Example 12.3)TOP: solutions | colligative properties KEY: expressing concentration | molalityMSC: general chemistry

54. What is the molality of a solution prepared by dissolving 0.244 mol of chloroform, CHCl3, in 456 g of toluene, C6H5CH3?A) 0.0642 mB) 0.0469 mC) 0.535 mD) 0.0492 mE) 1.113 m

ANS: C PTS: 1 DIF: easy REF: 12.4OBJ: Calculate the molality of solute. (Example 12.3)TOP: solutions | colligative properties KEY: expressing concentration | molalityMSC: general chemistry


55. What is the molality of a solution prepared by dissolving 2.57 g of urea, NH2CONH2, in 57.6 g of water?A) 0.0427 mB) 0.0446 mC) 0.0132 mD) 0.743 mE) 0.000711 m

ANS: D PTS: 1 DIF: easy REF: 12.4OBJ: Calculate the molality of solute. (Example 12.3)TOP: solutions | colligative properties KEY: expressing concentration | molalityMSC: general chemistry

56. A 3.140 molal solution of NaCl is prepared. How many grams of NaCl are present in a sample containing 2.191 kg of water?A) 243.9 gB) 402.1 gC) 117.7 gD) 688.0 gE) none of these

ANS: B PTS: 1 DIF: moderate REF: 12.4OBJ: Calculate the molality of solute. (Example 12.3)TOP: solutions | colligative properties KEY: expressing concentration | molalityMSC: general chemistry

57. What is the molality of a solution that contains 77.7 g of 1,4-dichlorobenzene (C6H4Cl2) in 445 mL of carbon tetrachloride (CCl4)? The density of CCl4 is 1.60 g/mL.A) 0.183 mB) 0.743 mC) 0.175 mD) 0.109 mE) 1.90 m

ANS: B PTS: 1 DIF: moderate REF: 12.4OBJ: Calculate the molality of solute. (Example 12.3)TOP: solutions | colligative properties KEY: expressing concentration | molalityMSC: general chemistry

58. What is the molality of ethanol, C2H5OH, in an aqueous solution that is 51.0% ethanol by mass?A) 1.04 mB) 0.0226 mC) 22.6 mD) 0.719 mE) 53.4 m

ANS: C PTS: 1 DIF: moderate REF: 12.4OBJ: Calculate the molality of solute. (Example 12.3)TOP: solutions | colligative properties KEY: expressing concentration | conversion of concentration units MSC: general chemistry


59. A concentrated potassium hydroxide solution is 45.0% KOH by mass and has a density of 1.44 g/mL at 25°C. The remainder of material is solvent. What is the molality of KOH in the solution?

A) 14.6 mB) 8.02 mC) 5.53 mD) 686 mE) 1.02 m


60. What is the molality of a 20.0% by mass hydrochloric acid solution? The density of the solution is 1.0980 g/mL.A) 0.0220 mB) 6.86 mC) 0.200 mD) 5.68 mE) 6.02 m

ANS: B PTS: 1 DIF: moderate REF: 12.4OBJ: Calculate the molality of solute. (Example 12.3)TOP: solutions | colligative propertiesKEY: expressing concentration | conversion of concentration unitsMSC: general chemistry

61. What is the molality of a solution that contains 8.16 g of glucose, C6H12O6, in 252.5 g of water?A) 0.180 mB) 0.0453 mC) 0.00322 mD) 0.0114 mE) 0.0323 m

ANS: A PTS: 1 DIF: easy REF: 12.4OBJ: Calculate the molality of solute. (Example 12.3)TOP: phases | colligative properties KEY: expressing concentrationMSC: general chemistry

62. For a solution containing only one solute dissolved in a solvent, we can calculate the mole fraction of the solvent directly, given onlyA) the molar mass of the solute.B) the density of the solution.C) the molar mass of the solvent.D) the mole fraction of the solute.E) the molarity of the solution.


ANS: D PTS: 1 DIF: moderate REF: 12.4OBJ: Define mole fraction. TOP: solutions | colligative propertiesKEY: expressing concentration | mole fraction MSC: general chemistry

63. What is the mole fraction of urea, CH4N2O, in an aqueous solution that is 36% urea by mass?A) 0.14B) 0.86C) 0.36D) 0.55E) 0.65

ANS: A PTS: 1 DIF: easy REF: 12.4OBJ: Calculate the mole fraction of components. (Example 12.4)TOP: solutions | colligative properties KEY: expressing concentration | mole fractionMSC: general chemistry

64. What is the mole fraction of urea, CO(NH2)2, in a solution prepared by dissolving 6.8 g of urea in 33.5 g of methanol, CH3OH?A) 0.83B) 0.17C) 0.098D) 0.90E) 0.28

ANS: C PTS: 1 DIF: easy REF: 12.4OBJ: Calculate the mole fraction of components. (Example 12.4)TOP: solutions | colligative properties KEY: expressing concentration | mole fractionMSC: general chemistry

65. What is the mole fraction of toluene in a solution of 3.4 mol of benzene and 5.2 mol of toluene?A) 0.64B) 0.54C) 0.60D) 0.24E) 0.40

ANS: C PTS: 1 DIF: easy REF: 12.4OBJ: Calculate the mole fraction of components. (Example 12.4)TOP: solutions | colligative properties KEY: expressing concentration | mole fractionMSC: general chemistry

66. What is the mole fraction of water in a solution that contains 6.8 mol of ethanol (C2H5OH) and 1.2 mol of water?A) 0.15B) 0.07C) 0.57D) 0.18E) 0.85


ANS: A PTS: 1 DIF: easy REF: 12.4OBJ: Calculate the mole fraction of components. (Example 12.4)TOP: solutions | colligative properties KEY: expressing concentration | mole fractionMSC: general chemistry

67. What is the mole fraction of water in a water–ethanol solution that is 46.0% water by mass? (Ethanol is C2H5OH.)A) 0.28B) 0.31C) 0.25D) 0.69E) 0.54

ANS: D PTS: 1 DIF: moderate REF: 12.4OBJ: Calculate the mole fraction of components. (Example 12.4)TOP: solutions | colligative propertiesKEY: expressing concentration | conversion of concentration unitsMSC: general chemistry

68. What is the mole fraction of urea in a solution that contains 2.1 mol of urea and 4.4 mol of water?A) 0.77B) 0.32C) 0.42D) 0.52E) 0.68

ANS: B PTS: 1 DIF: easy REF: 12.4OBJ: Calculate the mole fraction of components. (Example 12.4)TOP: solutions | colligative properties KEY: expressing concentration | mole fractionMSC: general chemistry

69. Which way of expressing concentration is used to relate the vapor pressure of a solution to the amount of nonvolatile solute dissolved in the solution?A) mole fractionB) molarityC) osmotic pressureD) mass percentE) molality

ANS: A PTS: 1 DIF: easy REF: 12.5OBJ: State Raoult’s law. TOP: solutions | colligative propertiesKEY: vapor pressure of a solution | Raoult's law MSC: general chemistry


70. When 1 mol of a nonvolatile nonelectrolyte is dissolved in 3 mol of a solvent, the vapor pressure of the solution compared with that of the pure solvent isA) 1/4.B) 4/5.C) 1/2.D) 1/5.E) 3/4.

ANS: E PTS: 1 DIF: easy REF: 12.5OBJ: Calculate vapor-pressure lowering. (Example 12.9)TOP: solutions | colligative propertiesKEY: vapor pressure of a solution | Raoult's law MSC: general chemistry

71. What is the vapor pressure at 20°C of an ideal solution prepared by the addition of 8.87 g of the nonvolatile solute urea, CO(NH2)2, to 57.6 g of methanol, CH3OH? The vapor pressure of pure methanol at 20°C is 89.0 mmHg.A) 6.75 mmHgB) 69.1 mmHgC) 77.1 mmHgD) 82.2 mmHgE) 19.9 mmHg

ANS: D PTS: 1 DIF: easy REF: 12.5OBJ: Calculate vapor-pressure lowering. (Example 12.9)TOP: solutions | colligative propertiesKEY: vapor pressure of a solution | vapor pressure lowering MSC: general chemistry

72. What is the vapor pressure at 75°C of an aqueous solution prepared by the addition of 64.3 g of the nonvolatile solute urea, CO(NH2)2, to 174 g of water? The vapor pressure of pure water at 75°C is 290. mmHg.A) 133 mmHgB) 28.9 mmHgC) 167 mmHgD) 261 mmHgE) 212 mmHg

ANS: D PTS: 1 DIF: easy REF: 12.5OBJ: Calculate vapor-pressure lowering. (Example 12.9)TOP: solutions | colligative propertiesKEY: vapor pressure of a solution | vapor pressure lowering MSC: general chemistry

73. Benzene, C6H6, and toluene, C6H5CH3, form ideal solutions. At 35°C the vapor pressure of benzene is 160. torr and that of toluene is 50.0 torr. In an experiment, 67.6 g of benzene and 86.7 g of toluene are placed in a closed container at 35°C. At equilibrium, what is the partial vapor pressure of toluene?A) 108 torrB) 83.3 torrC) 24.0 torrD) 76.7 torrE) 26.0 torr


ANS: E PTS: 1 DIF: difficult REF: 12.5OBJ: Calculate vapor-pressure lowering. (Example 12.9)TOP: solutions | colligative propertiesKEY: vapor pressure of a solution | Raoult's law MSC: general chemistry

74. Benzene, C6H6, and toluene, C6H5CH3, form ideal solutions. At 35°C the vapor pressure of benzene is 160. torr and that of toluene is 50.0 torr. In an experiment, 3.6 mol of benzene and 5.5 mol of toluene are placed in a closed container at 35°C and allowed to come to equilibrium. What is the mole fraction of toluene in the vapor phase?A) 0.52B) 0.68C) 0.32D) 0.14E) 0.60

ANS: C PTS: 1 DIF: difficult REF: 12.5OBJ: Calculate vapor-pressure lowering. (Example 12.9)TOP: solutions | colligative propertiesKEY: vapor pressure of a solution | Raoult's law MSC: general chemistry

75. A liquid–liquid solution is called an ideal solution if

I. it obeys PV = nRT.II. it obeys Raoult's law.III. solute–solute, solvent–solvent, and solute–solvent interactions are very similar.IV. solute–solute, solvent–solvent, and solute–solvent interactions are quite

different.

A) I, III, IVB) I, II, IIIC) II, III onlyD) I, II, IVE) II, IV only

ANS: C PTS: 1 DIF: easy REF: 12.5OBJ: Describe an ideal solution. TOP: solutions | colligative propertiesKEY: vapor pressure of a solution | Raoult's law MSC: general chemistry

76. A solution of two liquids, A and B, shows negative deviation from Raoult's law. This means thatA) the two liquids have a positive heat of solution.B) molecules of A interact more strongly with B than A molecules interact with A or

B molecules interact with B.C) molecules of A interact strongly with other A-type molecules.D) molecules of A interact weakly, if at all, with B molecules.E) molecules of A hinder the strong interaction between B molecules.

ANS: B PTS: 1 DIF: moderate REF: 12.5OBJ: Describe an ideal solution. TOP: solutions | colligative propertiesKEY: vapor pressure of a solution | Raoult's law MSC: general chemistry


77. A solution of CF3H in H2CO is most likely toA) be ideal.B) not be ideal, but the deviations cannot be predicted.C) show negative deviations from Raoult's law.D) obey Raoult's law.E) show positive deviations from Raoult's law.

ANS: C PTS: 1 DIF: moderate REF: 12.5OBJ: Describe an ideal solution. TOP: solutions | colligative propertiesKEY: vapor pressure of a solution | Raoult's law MSC: general chemistry

78. The fact that the boiling point of a pure solvent is lower than the boiling point of a solution of the same solvent is a direct consequence of theA) freezing-point depression of the solution.B) vapor pressure of the solution being higher than the vapor pressure of the pure

solvent.C) osmotic pressure of the solvent being lower than the osmotic pressure of the

solution.D) vapor pressure of the solution being lower than the vapor pressure of the pure

solvent.E) osmotic pressure of the solvent being higher than the osmotic pressure of the

solution.

ANS: D PTS: 1 DIF: difficult REF: 12.6OBJ: Define boiling–point elevation and freezing-point depression.TOP: solutions | colligative properties KEY: boiling point elevationMSC: general chemistry

79. A solute added to a solvent raises the boiling point of the solution becauseA) the temperature to cause boiling must be great enough to boil not only the solvent

but also the solute.B) the solute particles raise the solvent's vapor pressure, thus requiring a higher

temperature to cause boiling.C) the solute increases the volume of the solution, and an increase in volume requires

an increase in the temperature to reach the boiling point (derived from PV = nRT).D) the solute particles lower the solvent's vapor pressure, thus requiring a higher

temperature to cause boiling.E) two of these explanations are correct.

ANS: D PTS: 1 DIF: moderate REF: 12.6OBJ: Define boiling–point elevation and freezing-point depression.TOP: solutions | colligative properties KEY: boiling point elevationMSC: general chemistry


80. What is the freezing point of a 0.24 m solution of glucose, C6H12O6, in water? (Kf for water is 1.858°C/m.)A) 0.22°CB) 0.45°CC) –0.45°CD) –0.22°CE) –0.89°C

ANS: C PTS: 1 DIF: easy REF: 12.6OBJ: Calculate boiling-point elevation and freezing-point depression. (Example 12.10)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

81. What is the boiling-point change for a solution containing 0.432 mol of naphthalene (a nonvolatile, nonionizing compound) in 250. g of liquid benzene? (Kb = 2.53°C/m for benzene)A) 4.37 °CB) 5.86 °CC) 0.273 °CD) 1.46 °CE) 1.093 °C

ANS: A PTS: 1 DIF: easy REF: 12.6OBJ: Calculate boiling-point elevation and freezing-point depression. (Example 12.10)TOP: solutions | colligative properties KEY: boiling point elevationMSC: general chemistry

82. Substance A has a greater molar mass than substance B. If 50 g of substance A are dissolved in 250 g of water in one beaker, and 50 g of substance B are dissolved in 250 g of water in another beaker, thenA) the vapor pressure of solution A will be lower than the vapor pressure of

solution B.B) the solution of A will freeze at a lower temperature than the solution of B.C) the two solutions will have the same vapor pressure.D) the boiling point of solution A will be lower than the boiling point of solution B.E) the solution of A will have a higher osmotic pressure than the solution of B.

ANS: D PTS: 1 DIF: moderate REF: 12.6OBJ: Calculate boiling-point elevation and freezing-point depression. (Example 12.10)TOP: solutions | colligative properties KEY: boiling point elevationMSC: general chemistry

83. A solution consisting of 0.228 mol of methylbenzene, C6H5CH3, in 255 g of nitrobenzene, C6H5NO2, freezes at –0.3°C. Pure nitrobenzene freezes at 6.0°C. What is the freezing-point depression constant of nitrobenzene?A) 1.1°C/mB) 27°C/mC) 14.0°C/mD) 3.5°C/mE) 7.0°C/m


ANS: E PTS: 1 DIF: moderate REF: 12.6OBJ: Calculate boiling-point elevation and freezing-point depression. (Example 12.10)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

84. What is the mass percent of ethylene glycol (HOCH2CH2OH) in a solution of ethylene glycol in water that has a freezing point of –19.2°C? (Kf for water is 1.858°C/m.)A) 99.8%B) 39.1%C) 64.1%D) 60.1%E) 10.3%

ANS: B PTS: 1 DIF: difficult REF: 12.6OBJ: Calculate boiling-point elevation and freezing-point depression. (Example 12.10)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

85. Which of the following methods cannot be used to determine the molar mass of a nonelectrolyte?A) measurement of the freezing-point depression of a solution of the compoundB) measurement of the boiling-point elevation of a solution of the compoundC) measurement of the pressure, temperature, volume, and mass of the compound in

the gaseous stateD) measurement of the x-ray diffraction of a pure crystal of the compoundE) measurement of the osmotic pressure of a solution of the compound

ANS: D PTS: 1 DIF: moderate REF: 12.6OBJ: Calculate the molecular mass of a solute from molality. (Example 12.11)TOP: solutions | colligative properties MSC: general chemistry

86. Trimellitic acid is an organic acid that has a composition of 51.44% C, 2.88% H, and 45.68% O by mass. A 5.02-g sample of trimellitic acid dissolved in 20 g of acetone, CH3COCH3, has a boiling point of 58.24°C. What is the molecular formula of trimellitic acid? (Kb for acetone is 1.71°C/m, and pure acetone has a boiling point of 56.20°C.)A) CH2OB) C9H6O6

C) C3HO2

D) C18HO16

E) C6H2O4

ANS: B PTS: 1 DIF: difficult REF: 12.6OBJ: Calculate the molecular mass from freezing-point depression. (Example 12.12)TOP: solutions | colligative properties KEY: boiling point elevationMSC: general chemistry


87. When a 28.4-g sample of an unknown compound is dissolved in 500. g of benzene, the freezing point of the resulting solution is 3.77°C. The freezing point of pure benzene is 5.48°C, and Kf for benzene is 5.12°C/m. Calculate the molar mass of the unknown compound.A) 145 g/molB) 170. g/molC) 85.0 g/molD) 340 g/molE) 16.6 g/mol

ANS: B PTS: 1 DIF: easy REF: 12.6OBJ: Calculate the molecular mass from freezing-point depression. (Example 12.12)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

88. Thyroxine, an important hormone that controls the rate of metabolism in the body, can be isolated from the thyroid gland. If 0.453 g of thyroxine is dissolved in 10.0 g of benzene, the freezing point of the solution could be measured as 5.144°C. Pure benzene freezes at 5.444°C and has a value for the molal freezing-point-depression constant of Kf of 5.12°C/m. What is the approximate molar mass of thyroxine?A) 773 g/molB) 7.73 g/molC) 7.73 105 g/molD) 42.6 g/molE) 11.3 g/mol

ANS: A PTS: 1 DIF: moderate REF: 12.6OBJ: Calculate the molecular mass from freezing-point depression. (Example 12.12)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

89. If a 18.0-g sample of a nonelectrolyte is dissolved in 112.0 g of water, the resulting solution will freeze at –0.94°C. What is the molar mass of the nonelectrolyte? (Kf for water is 1.858°C/m.)A) 77 g/molB) 0.32 g/molC) 550 g/molD) 280 g/molE) 320 g/mol

ANS: E PTS: 1 DIF: moderate REF: 12.6OBJ: Calculate the molecular mass from freezing-point depression. (Example 12.12)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry


90. What is the molar mass of an aromatic hydrocarbon if 0.85 g of the compound depresses the freezing point of 128 g of benzene by 0.37°C? (Kf for benzene is 5.12°C/m.)A) 35 g/molB) 150 g/molC) 93 g/mol 92D) 2100 g/molE) 140 g/mol

ANS: C PTS: 1 DIF: moderate REF: 12.6OBJ: Calculate the molecular mass from freezing-point depression. (Example 12.12)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

91. Which of the following will cause the calculated molar mass of a compound determined by the freezing-point-depression method to be greater than the true molar mass?A) When the solute was added, some was spilled on the lab bench.B) Water gets into the solvent after the freezing point of the pure solvent is

determined.C) Some of the solute molecules break apart.D) The mass of solvent is smaller than that determined from the weighing.E) all of the above

ANS: A PTS: 1 DIF: moderate REF: 12.6OBJ: Calculate the molecular mass from freezing-point depression. (Example 12.12)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

92. A compound containing carbon and nitrogen has a composition of 46.16% carbon and 53.84% nitrogen by mass. A solution prepared by dissolving 1.542 g of this compound in 30.00 g of carbon tetrachloride, CCl4, produces a solution that boils at 81.69°C. What is the molecular formula of the compound? (Kb for CCl4 is 5.03°C/m, and pure CCl4 has a freezing point of 76.72°C.)A) C2N2

B) CN2

C) C3N3

D) CNE) C2N4

ANS: A PTS: 1 DIF: difficult REF: 12.6OBJ: Calculate the molecular mass from freezing-point depression. (Example 12.12)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

93. A compound containing sulfur, nitrogen, and hydrogen has a composition of 86.6% sulfur, 12.6% nitrogen, and 0.91% hydrogen by mass. A solution prepared by dissolving 2.072 g of this compound in 35.00 g of bromoform, CHBr3, produces a solution that freezes at 3.97°C. What is the molecular formula of the compound? (Kf for bromoform is 14.4°C/m, and pure bromoform has a freezing point of 7.8°C.)


A) SNHB) S3N2H2

C) S6N2H2

D) S3NHE) S2N2H2

ANS: C PTS: 1 DIF: difficult REF: 12.6OBJ: Calculate the molecular mass from freezing-point depression. (Example 12.12)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

94. A cucumber is placed in a concentrated salt solution. What is most likely to happen?A) Water will flow from the solution to the cucumber.B) No change will occur.C) Salt will flow into the cucumber.D) Salt will precipitate out.E) Water will flow from the cucumber to the solution.

ANS: E PTS: 1 DIF: moderate REF: 12.7OBJ: Describe a system where osmosis will take place.TOP: solutions | colligative properties KEY: osmotic pressureMSC: general chemistry

95. A red blood cell placed in pure water will swell becauseA) the osmotic pressure is greater in the water than in the cell.B) the osmotic pressure is the same in the cell and the water.C) the osmotic pressure is greater in the cell than in the water.D) water moves from a higher osmotic pressure to a lower osmotic pressure.E) the vapor pressure of the water in the cell is greater than the vapor pressure of pure

water.

ANS: C PTS: 1 DIF: easy REF: 12.7OBJ: Describe a system where osmosis will take place.TOP: solutions | colligative properties KEY: hypotonic solutionMSC: general chemistry

96. What is reverse osmosis?A) the application, to a dilute solution, of a pressure that is greater than the osmotic

pressure, such that solvent flows from the concentrated solution to the dilute solution

B) the application, to a dilute solution, of a pressure that is greater than the osmotic pressure, such that solute flows from the concentrated solution to the dilute solution

C) the application, to a concentrated solution, of a pressure that is greater than the osmotic pressure, such that solute flows from the concentrated solution to the dilute solution


D) the application, to a concentrated solution, of a pressure that is greater than the osmotic pressure, such that solvent flows from the concentrated solution to the dilute solution

E) the application, to a concentrated solution, of a pressure that is greater than the osmotic pressure, such that solvent flows from the dilute solution to the concentrated solution

ANS: D PTS: 1 DIF: easy REF: 12.7OBJ: Describe a system where osmosis will take place.TOP: solutions | colligative properties KEY: osmotic pressureMSC: general chemistry

97. A solution of water and a nonvolatile, nonionizing compound is placed in a tube with a semipermeable membrane on one side. The tube is placed in a beaker of pure water. What initial net effect will occur?A) Nothing will move through the membrane either way.B) Water will flow from the beaker to the tube.C) Water will flow from the tube to the beaker.D) Equilibrium will be immediately established.E) The compound will pass through the membrane into the solution.

ANS: B PTS: 1 DIF: easy REF: 12.7OBJ: Describe a system where osmosis will take place.TOP: solutions | colligative properties KEY: osmotic pressureMSC: general chemistry

98. Determine the osmotic pressure of a solution that contains 0.014 g of a hydrocarbon solute (molar mass = 340 g/mol) dissolved in benzene to make a 350-mL solution. The temperature is 20.0°C.A) 0.9 torrB) 2.0 torrC) 0.14 torrD) 0.7 torrE) 2.1 torr

ANS: E PTS: 1 DIF: easy REF: 12.7OBJ: Calculate osmotic pressure. (Example 12.13)TOP: solutions | colligative properties KEY: osmotic pressureMSC: general chemistry

99. A 2.4-g sample of a small protein having a molecular weight of 62,000 g/mol is dissolved in 59.6 mL of water at 29°C. What is the osmotic pressure of the solution? (R = 0.0821 L · atm/(K · mol))A) 12 mmHgB) 760 mmHgC) 1.2 mmHgD) 47,000 mmHgE) 0.016 mmHg


ANS: A PTS: 1 DIF: easy REF: 12.7OBJ: Calculate osmotic pressure. (Example 12.13)TOP: solutions | colligative properties KEY: osmotic pressure | colligative propertiesMSC: general chemistry

100. Osmotic pressure isA) inversely proportional to mass fraction.B) directly proportional to lattice energy.C) inversely proportional to molality.D) inversely proportional to mole fraction.E) directly proportional to molarity.

ANS: E PTS: 1 DIF: easy REF: 12.7OBJ: Calculate osmotic pressure. (Example 12.13)TOP: solutions | colligative properties KEY: osmotic pressure | colligative propertiesMSC: general chemistry

101. Calculate the molecular weight of a small protein if a 0.24-g sample dissolved in 108 mL of water has an osmotic pressure of 9.5 mmHg at 22°C. (R = 0.0821 L · atm/(K · mol))A) 3.2 102 g/molB) 4.3 103 g/molC) 5.7 g/molD) 1.8 102 g/molE) 5.7 10–3 g/mol

ANS: B PTS: 1 DIF: moderate REF: 12.7OBJ: Calculate osmotic pressure. (Example 12.13)TOP: solutions | colligative properties KEY: osmotic pressure | colligative propertiesMSC: general chemistry

102. To determine the molar mass of a small protein in the range of 20,000–40,000 g/mol, it would be best to measureA) the freezing point of the solvent and of the solution and the weight of the solute

and solvent.B) the boiling point of the solvent and of the solution and the weight of the solute and

solvent.C) the vapor pressure of the solvent and of the solution and the weight of the solute

and solvent.D) the osmotic pressure of the solution and the weight of the solute and solvent.E) the density of the protein and to make x-ray measurements.

ANS: D PTS: 1 DIF: difficult REF: 12.7OBJ: Calculate osmotic pressure. (Example 12.13)TOP: solutions | colligative properties KEY: osmotic pressure | colligative propertiesMSC: general chemistry


103. For a dilute solution of (NH4)3PO4, the van’t Hoff factor (i) would be approximately

A) 4.B) 2.C) 3.D) 1.E) 5.

ANS: A PTS: 1 DIF: easy REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties NOT: REVISED

104. For a dilute solution of FeCl3, the van’t Hoff factor (i) would be approximately

A) 4.B) 2.C) 3.D) 1.E) 5.

ANS: A PTS: 1 DIF: easy REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties NOT: REVISED

105. Based on the formulas of the following solutes, which compound would have the smallest van’t Hoff factor (i)?A) Ca(NO3)2(aq)B) K2SO4(aq)C) Th(SO4)2(aq)D) Al2(SO4)3(aq)E) MgSO4(aq)

ANS: E PTS: 1 DIF: easy REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties MSC: general chemistry

106. Which of the following solutes in aqueous solution would be expected to exhibit the smallest freezing-point lowering (assuming ideal behavior)?

A) 0.1 m NaClB) 0.2 m CH3COOHC) 0.05 m Al2(SO4)3

D) 0.1 m MgCl2

E) 0.25 m NH3

ANS: A PTS: 1 DIF: easy-moderateREF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties


107. Which of the following solutions would have the highest osmotic pressure?A) 0.15 M MgBr2

B) 0.15 M NaClC) 0.20 M C12H22O11

D) 0.20 M C6H12O6

E) 0.20 M CH3OH

ANS: A PTS: 1 DIF: moderate REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties KEY: osmotic pressure | colligative propertiesMSC: general chemistry

108. What is the freezing point of an aqueous 1.66 m CaCl2 solution? (Kf for water is 1.858°C/m.)A) 9.3°CB) 3.1°CC) –9.3°CD) 0.0°CE) –3.1°C

ANS: C PTS: 1 DIF: moderate REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

109. Which of the following amounts of solute, dissolved in 1.0 kg of water, creates a solution with the lowest freezing temperature? (assuming ideal behavior)

A) 0.0015 mol of sulfuric acid, H2SO4

B) 0.0015 mol of H2SO3

C) 0.0030 mol of ethanol, C2H5OHD) 0.0030 mol of methanol, CH3OHE) 0.0015 mol of sucrose, C12H22O11

ANS: A PTS: 1 DIF: moderate REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties

110. Which of the following solutes, dissolved in 1.0 kg of water, creates a solution that boils at the highest temperature?A) 0.010 mol H3PO4

B) 0.010 mol HClO4

C) 0.010 mol H2SO4

D) 0.010 mol HClE) 0.010 mol HF

ANS: C PTS: 1 DIF: moderate REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry


111. Which of the following solutes, dissolved in 1000 g of water, would provide a solution with the lowest freezing point?A) 0.030 mol of barium chloride, BaCl2

B) 0.030 mol of urea, CO(NH2)2

C) 0.030 mol of calcium sulfate, CaSO4

D) 0.030 mol of acetic acid, CH3COOHE) 0.030 mol of ammonium nitrate, NH4NO3

ANS: A PTS: 1 DIF: moderate REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties KEY: freezing point depressionMSC: general chemistry

112. Which of the following solutions has the lowest osmotic pressure?A) 0.10 M Al(NO3)3

B) 0.20 M C6H12O6

C) 0.15 M Ba(NO3)2

D) 0.10 M CaCl2

E) 0.15 M Na2S

ANS: B PTS: 1 DIF: moderate REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties KEY: osmotic pressureMSC: general chemistry

113. At 37°C, what is the osmotic pressure of a 0.59% NaCl by weight aqueous solution? Assume the density of the solution is 1.0 g/mL. (R = 0.0821 L · atm/(K · mol))A) 0.26 atmB) 2.6 atmC) 3.0 102 atmD) 5.1 atmE) 0.61 atm

ANS: D PTS: 1 DIF: moderate REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties KEY: osmotic pressureMSC: general chemistry

114. For which of the following aqueous solutions would one expect to have the largest van’t Hoff factor (i)?A) 0.400 m K2SO4

B) 0.400 m NaClC) 0.400 m C6H12O6 (glucose)D) 0.040 m K2SO4

E) 0.040 m NaCl

ANS: A PTS: 1 DIF: moderate REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties MSC: general chemistry


115. The molal boiling-point constant for water is 0.51°C/molal. The boiling point of a 1.00 m solution of Ca(NO3)2 should be increased byA) exactly 1.53°C.B) exactly 1.02°C.C) somewhat less than 1.02°C.D) exactly 0.51°C.E) somewhat less than 1.53°C.

ANS: E PTS: 1 DIF: moderate REF: 12.8OBJ: Determine the colligative properties of ionic solutions. (Example 12.14)TOP: solutions | colligative properties KEY: boiling point elevationMSC: general chemistry

116. What type of colloid is formed when a liquid is dispersed in a gas?A) foamB) emulsionC) aerosolD) solE) gel

ANS: C PTS: 1 DIF: easy REF: 12.9OBJ: Define colloid. TOP: solutions | colloid formationKEY: colloid | types of colloid MSC: general chemistry

117. What type of colloid is formed when a gas is dispersed in a solid?A) foamB) aerosolC) solD) emulsionE) gel

ANS: A PTS: 1 DIF: easy REF: 12.9OBJ: Define colloid. TOP: solutions | colloid formationKEY: colloid | types of colloid MSC: general chemistry

118. What type of colloid is formed when a liquid is dispersed in a solid?A) emulsionB) gelC) solD) foamE) aerosol

ANS: B PTS: 1 DIF: easy REF: 12.9OBJ: Define colloid. TOP: solutions | colloid formationKEY: colloid | types of colloid MSC: general chemistry


119. What type of colloid is formed when a solid is dispersed in a liquid?A) emulsionB) gelC) aerosolD) solE) foam

ANS: D PTS: 1 DIF: easy REF: 12.9OBJ: Define colloid. TOP: solutions | colloid formationKEY: colloid | types of colloid MSC: general chemistry

120. When a liquid is dispersed in another liquid, the resulting colloid is called a(n)A) emulsion.B) sol.C) foam.D) aerosol.E) gel.

ANS: A PTS: 1 DIF: easy REF: 12.9OBJ: Define colloid. TOP: solutions | colloid formationKEY: colloid | types of colloid MSC: general chemistry

121. A suspension of silver particles in water is most likely to form what type of colloid?A) aerosolB) micelleC) hydrophobic colloidD) association colloidE) hydrophilic colloid

ANS: C PTS: 1 DIF: easy REF: 12.9OBJ: Give examples of hydrophilic colloids and hydrophobic colloids.TOP: solutions | colloid formation KEY: colloid | hydrophobic colloidMSC: general chemistry

122. Which of the following statements describes the process of coagulation?A) The dispersed phase of an association colloid aggregates and forms a hydrophilic

colloid.B) The continuous phase of a colloid aggregates and separates from the dispersed

phase.C) The dispersed phase of an association colloid aggregates and forms a hydrophobic

colloid.D) The dispersed phase of a colloid aggregates and separates from the continuous

phase.E) The dispersed phase of an association colloid aggregates and forms a micelle.

ANS: D PTS: 1 DIF: easy REF: 12.9OBJ: Describe coagulation. TOP: solutions | colloid formationKEY: colloid | coagulation MSC: general chemistry


123. A suspension of sodium dodecanoate, CH3(CH2)10COONa, in water is most likely to form what type of colloid?A) hydrophilic colloidB) association colloidC) emulsionD) aerosolE) hydrophobic colloid

ANS: B PTS: 1 DIF: easy REF: 12.9OBJ: Explain how micelles can form an association colloid.TOP: solutions | colloid formation KEY: colloid | association colloidMSC: general chemistry

124. Synthetic detergent dispersed in water is an example of a(n)A) micelle.B) hydrophilic colloid.C) coagulant.D) hydrophobic colloid.E) association colloid.

ANS: E PTS: 1 DIF: easy REF: 12.9OBJ: Explain how micelles can form an association colloid.TOP: solutions | colloid formation KEY: colloid | association colloidMSC: general chemistry


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