Chapter 12 & 13 Practice test:
NAME __________________________
Ions in Aqueous Solutions and Colligative Properties
______ 1. A solute whose water solution conducts electricity is called a(n)
a. nonconductor.
b. electrolyte.
c. non-electrolyte.
______ 2. Which solution has the highest boiling point?
a. 0.50 m glucose in water
c. 0.20 m glucose in water
d. aqueous solution.
b. 0.50 m potassium iodide in water
d. 0.40 m calcium chloride in water
______ 3. When an ionic solid dissolves in water, which of the following does not occur?
a. The compound dissociates.
b. Hydration occurs.
c. The compound ionizes.
d. Polar ends of water molecules approach the ions, releasing energy.
______ 4. Colligative properties depend on the
a. number of solute particles present.
c. mass of solute particles present.
b. size of solute particles present.
d. charge on solute particles present.
______ 5. Nonvolatile solutes
a. depress both the freezing point and the boiling point.
c. depress the freezing point and elevate the boiling point.
b. elevate both the freezing point and the boiling point.
d. elevate the freezing point and depress the boiling point.
______ 6. What is the molarity of a solution that contains 0.202 mol KCl (molar mass = 74.55 g/mol) in 7.98 L of solution?
a. 0.0132 M KCl
b. 0.0253 M KCl
c. 0.459 M KCl
d. 1.36 M KCl
Use this figure to answer questions 7 and 8.
______ 7. A solution containing 35 g of Li2SO4 dissolved in 100 g of water is heated from 10°C to 90°C. According to information
in the figure, this temperature change would result in
a. an additional 5 g of Li2SO4 in solution.
b. an additional 30 g of Li2SO4 in solution.
c. 5 g of Li2SO4 precipitate.
d. no change in Li2SO4 concentration.
______ 8. According to saturation curves shown in the figure, which of the following solutions is supersaturated?
a. 40 g of NaCH3COO in 100 g of water at 40°C
b. 140 g of NaCH3COO in 100 g of water at 80°C
c. 80 g of NaCH3COO in 100 g of water at 40°C
d. 80 g of NaCH3COO in 200 g of water at 40°C
_____ 9. Which of the following is an ionic compound that dissociates in water?
a. NaCl
b. C12
c. CCl4
d. C6H6
______10. What is the molarity of a solution that contains 125 g NaCl (molar mass = 58.44 g/mol) in 4.00 L solution?
a. 0.535 M NaCl
b. 2.14 M NaCl
c. 8.56 M NaCl
d. 31.3 M NaCl
______11. What happens when a weak electrolyte dissolves in water?
a. The boiling point decreases.
b. The solution does not conduct electricity.
c. Few ions form.
d. 100% of the molecules ionize.
______12. What is the freezing point of a 1.5 m solution of sucrose in water?
(Kf = -1.86C/m)
a. -2.8C
b. -1.2C
c. -0.81C
d. 0.81C
_____13. What concentration of ethylene glycol is needed to raise the boiling point of water to 105C? (Kb = 0.51C/m)
a. 1.5 m
b. 2.5 m
c. 9.8 m
d. 205 m
______14. Compared with a 1.0 m solution of C12H22O11, the vapor pressure of a 1.0 m solution of C6H12O6
a. is exactly double.
b. is the same.
c. is exactly half.
d. cannot be determined.
______15. How many moles of Cl- ions are produced when 0.5 mol of NaCl is dissolved in water?
a. 0.5
b. 1.0
c. 1.5
d. 2.0
______16. What is the volume of a 1.44 M solution o f potassium sulfide (K2S) that contains 113.0 g of K2S?
a. 0.711 L
b. 1.02 L
c. 1.40 L
d. not enough info.
______ 17. Which solute will have the greatest effect on the boiling point of water?
a. C6H12O6
b. NaCl
c. HF
d. CH3COOH
______18. What is the approximate freezing-point depression of a 0.10 m aqueous CaCl2 solution? (Kf = -1.86C/m)
a. -0.76C
b. -0.56C
c. -0.38C
d. -0.19C
______19. How many grams lye (NaOH) are needed to make a 1.5 liters of a 0.025 M solution of lye to make soap?
a. .025 g
b. 40 g
c. 1.5 g
d. 2.1 g
______20. Electrolytes have a greater effect on colligative properties than non-electrolytes do because electrolytes
a. are volatile.
c. produce fewer moles of solute particles per mole of solvent.
b. have higher boiling points.
d. produce more moles of solute particles per mole of solvent.
______21. A 12 m acetic acid solution is
a. concentrated and a weak electrolyte.
c. concentrated and a strong electrolyte.
b. dilute and a weak electrolyte.
d. dilute and a strong electrolyte.
______22. A 2 m solution contains
a. 2 mol of solute dissolved in 1 L of solvent.
c. 2 mol of solute dissolved in 1 mol of solvent.
b. 1 mol of solute dissolved in 2 L of solvent.
d. 2 mol of solute dissolved in 1 kg of solvent.
______23. What is the boiling-point elevation of a solution made from 15.0 g of a non-electrolyte solute and 250.0 g of water?
The molar mass of the solute is 50.0 g and Kb = 0.51C/m.
a. 0.0700C
b. 0.292C
c. 0.311C
d. 0.612C
______24. The hydronium ion forms when hydrogen ions
a. dissociate.
b. ionize.
c. combine with HCl.
d. combine with H2O.
______25. What is the expected boiling point of a solution of 128 g KCl (a strong electrolyte) dissolved in 1.3 kg of water. The
molar mass of KCl is 74.55 g and Kb _
0.51C/m.
a. 98.7C
b. 99.5C
c. 100.7C
d. 101.3
ANSWER KEY
______ 1. A solute whose water solution conducts electricity is called a(n)
a. nonconductor.
b. electrolyte.
c. non-electrolyte.
d. aqueous solution.
______ 2. Which solution has the highest boiling point?
a. 0.50 m glucose in water
b. 0.50 m potassium iodide in water
c. 0.20 m glucose in water
d. 0.40 m calcium chloride in water
______ 3. When an ionic solid dissolves in water, which of the following does not occur?
a. The compound dissociates.
b. Hydration occurs.
c. The compound ionizes.
d. Polar ends of water molecules approach the ions, releasing energy.
______ 4. Colligative properties depend on the
a. number of solute particles present.
b. size of solute particles present.
c. mass of solute particles present.
d. charge on solute particles present.
______ 5. Nonvolatile solutes
a. depress both the freezing point and the boiling point.
b. elevate both the freezing point and the boiling point.
c. depress the freezing point and elevate the boiling point.
d. elevate the freezing point and depress the boiling point.
______ 6. What is the molarity of a solution that contains 0.202 mol KCl
(molar mass = 74.55 g/mol) in 7.98 L of solution?
a. 0.0132 M KCl
b. 0.0253 M KCl
c. 0.459 M KCl
d. 1.36 M KCl
Use this figure to answer questions 7 and 8.
______ 7. A solution containing 35 g of Li2SO4 dissolved in 100 g of water is heated from 10°C to
90°C. According to information in the figure, this temperature change would result in
a. an additional 5 g of Li2SO4 in solution.
b. an additional 30 g of Li2SO4 in solution.
c. 5 g of Li2SO4 precipitate.
d. no change in Li2SO4 concentration.
______ 8. According to saturation curves shown in the figure, which of the
following solutions is supersaturated?
a. 40 g of NaCH3COO in 100 g of water at 40°C
b. 140 g of NaCH3COO in 100 g of water at 80°C
c. 80 g of NaCH3COO in 100 g of water at 40°C
d. 80 g of NaCH3COO in 200 g of water at 40°C
_____ 9. Which of the following is an ionic compound that dissociates in water?
a. NaCl
b. C12
c. CCl4
d. C6H6
______10. What is the molarity of a solution that contains 125 g NaCl (molar
mass = 58.44 g/mol) in 4.00 L solution?
a. 0.535 M NaCl b. 2.14 M NaCl
c. 8.56 M NaCl
d. 31.3 M NaCl
______11. What happens when a weak electrolyte dissolves in water?
a. The boiling point decreases.
b. The solution does not conduct electricity.
c. Few ions form.
d. 100% of the molecules ionize.
______12. What is the freezing point of a 1.5 m solution of sucrose in water?
(Kf = -1.86C/m)
a. -2.8C
b. -1.2C
c. -0.81C
d. 0.81C
______13. What concentration of ethylene glycol is needed to raise the boiling
point of water to 105C? (Kb = 0.51C/m)
a. 1.5 m
b. 2.5 m
c. 9.8 m
d. 205 m
______14. Compared with a 1.0 m solution of C12H22O11, the vapor pressure of a
1.0 m solution of C6H12O6
a. is exactly double.
b. is the same.
c. is exactly half.
d. cannot be determined.
______15. How many moles of Cl- ions are produced when 0.5 mol of NaCl is dissolved in
water?
a. 0.5
b. 1.0
c. 1.5
d. 2.0
______16. What is the volume of a 1.44 M solution o f potassium sulfide (K2S) that
contains 113.0 g of K2S?
a. 0.711 L
b. 1.02 L
c. 1.40 L
d. not enough info.
______ 17. Which solute will have the greatest effect on the boiling point of water?
a. C6H12O6
b. NaCl
c. HF
d. CH3COOH
______18. What is the approximate freezing-point depression of a 0.10 m aqueous
CaCl2 solution? (Kf = -1.86C/m)
a. -0.76C
b. -0.56C
c. -0.38C
d. -0.19C
______19. How many grams lye (NaOH) are needed to make a 1.5 liters of a 0.025 M
solution of lye in the process of making soap?
a. .025 g
b. 40 g
c. 1.5 g
d. 2.1 g
______20. Electrolytes have a greater effect on colligative properties than
non-electrolytes do because electrolytes
a. are volatile.
b. have higher boiling points.
c. produce fewer moles of solute particles per mole of solvent.
d. produce more moles of solute particles per mole of solvent.
______21. A 12 m acetic acid solution is
a. concentrated and a weak electrolyte.
c. concentrated and a strong electrolyte.
b. dilute and a weak electrolyte.
d. dilute and a strong electrolyte.
______22.
a.
b.
c.
d.
A 2 m solution contains
2 mol of solute dissolved in 1 L of solvent.
1 mol of solute dissolved in 2 L of solvent.
2 mol of solute dissolved in 1 mol of solvent.
2 mol of solute dissolved in 1 kg of solvent.
______23. What is the boiling-point elevation of a solution made from 15.0 g of a nonelectrolyte solute and 250.0 g of water? The molar mass of the solute is 50.0 g and
Kb = 0.51C/m.
a. 0.0700C
b. 0.292C
c. 0.311C
d. 0.612C
______24. The hydronium ion forms when hydrogen ions
a. dissociate.
b. ionize.
c. combine with HCl.
d. combine with H2O.
______25. What is the expected boiling point of a solution of 128 g KCl (a strong
electrolyte) dissolved in 1.3 kg of water. The molar mass of KCl is 74.55 g and Kb _
0.51C/m.
a. 98.7C
b. 99.5C
c. 100.7C
d. 101.3C