Sample Exam EP 5 Midterm 2009 ch 16 questions

ep 5 sample exam

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.

____ 1. Which of the following usually makes a substance dissolve faster in a solvent?
a. agitating the solution
b. increasing the particle size of the solute
c. lowering the temperature
d. decreasing the number of particles


____ 2. What is the maximum amount of KCl that can dissolve in 200 g of water?
(The solubility of KCl is 34 g/100 g H2O at 20 C.)
a. 17 g c. 68 g
b. 34 g d. 6800 g


____ 3. What is the solubility of silver nitrate if only 11.1 g can dissolve in 5.0 g of water at 20 C?
a. at 20 C c. at 20 C
b. at 20 C d. at 20 C


____ 4. Which of the following expressions is generally used for solubility?
a. grams of solute per 100 grams of solvent
b. grams of solute per 100 milliliters of solvent
c. grams of solute per 100 grams of solution
d. grams of solute per 100 milliliters of solution


____ 5. Which of the following pairs of factors affects the solubility of a particular substance?
a. temperature and the nature of solute and solvent
b. temperature and degree of mixing
c. particle size and degree of mixing
d. particle size and temperature


____ 6. If a crystal added to an aqueous solution causes many particles to come out of the solution, the original solution was ____.
a. unsaturated c. an emulsion
b. saturated d. supersaturated


____ 7. Which of the following substances is less soluble in hot water than in cold water?
a. CO c. NaNO
b. NaCl d. KBr


____ 8. Which of the following occurs as temperature increases?
a. Solubility decreases. c. Solubility remains the same.
b. Solubility increases. d. Molarity doubles.


____ 9. The solubility of a gas in a liquid is ____.
a. proportional to the square root of the pressure of the gas above the liquid
b. directly proportional to the pressure of the gas above the liquid
c. inversely proportional to the pressure of the gas above the liquid
d. unrelated to the pressure of the gas above the liquid


____ 10. If the solubility of a particular solute is at 20 C, which of the following solution concentrations would represent a supersaturated aqueous solution of that solute?
a. at 25 C c. at 20 C
b. at 15 C d. at 20 C


____ 11. What happens to the solubility of a gas, in a liquid, if the partial pressure of the gas above the liquid decreases?
a. The solubility decreases. c. The solubility remains the same.
b. The solubility increases. d. The solubility cannot be determined.


____ 12. To increase the solubility of a gas at constant temperature from 1.20 g/L, at 1.4 atm, to 2.3 g/L, the pressure would have to be increased to ____.
a. 0.37 atm c. 1.37 atm
b. 0.7 atm d. 2.7 atm


____ 13. If the solubility of a gas in water is 4.0 g/L when the pressure of the gas above the water is 3.0 atm, what is the pressure of the gas above the water when the solubility of the gas is 1.0 g/L?
a. 0.75 atm c. 4.0 atm
b. 1.3 atm d. 12 atm


____ 14. In a concentrated solution there is ____.
a. no solvent c. a small amount of solute
b. a large amount of solute d. no solute


____ 15. What is the molarity of a solution that contains 6 moles of solute in 2 liters of solution?
a. 6M c. 7M
b. 12M d. 3M


____ 16. In which of the following is the solution concentration expressed in terms of molarity?
a. c.
b. d.


____ 17. Which of the following operations yields the number of moles of solute?
a. molarity moles of solution c. molarity mass of solution
b. molarity liters of solution d. moles of solution volume of solution


____ 18. What is the molarity of a solution containing 7.0 moles of solute in 569 mL of solution?
a. 81M c. 12M
b. 0.081M d. 4.0M


____ 19. What is the molarity of 200 mL of solution in which 2.0 moles of sodium bromide is dissolved?
a. 2.0M c. 0.40M
b. 10M d. 4.0M


____ 20. What is the number of moles of solute in 250 mL of a 0.4M solution?
a. 0.1 mol c. 0.62 mol
b. 0.16 mol d. 1.6 mol


____ 21. What is the molarity of a solution containing 56 grams of solute in 959 mL of solution? (molar mass of solute = 26 g/mol)
a. 1.5M c. 2.1M
b. 2.2M d. 0.0022M


____ 22. What mass of sucrose, C H O , is needed to make 500.0 mL of a 0.200M solution?
a. 34.2 g c. 17.1 g
b. 100 g d. 68.4 g


____ 23. What mass of Na SO is needed to make 2.5 L of 2.0M solution? (Na = 23 g; S = 32 g; O = 16 g)
a. 178 g c. 356 g
b. 284 g d. 710 g


____ 24. What does NOT change when a solution is diluted by the addition of solvent?
a. volume of solvent c. number of moles of solute
b. mass of solvent d. molarity of solution


____ 25. How many mL of a 2.0M NaBr solution are needed to make 200.0 mL of 0.50M NaBr?
a. 25 mL c. 100 mL
b. 50 mL d. 150 mL


____ 26. The volume of 6.00M HCl needed to make 319 mL of 6.80M HCl is ____.
a. 0.128 mL c. 281 mL
b. 7.8 mL d. 362 mL


____ 27. If 2.0 mL of 6.0M HCl is used to make a 500.0-mL aqueous solution, what is the molarity of the dilute solution?
a. 0.024M c. 0.30M
b. 0.24M d. 0.83M


____ 28. To 225 mL of a 0.80M solution of KI, a student adds enough water to make 1.0 L of a more dilute KI solution. What is the molarity of the new solution?
a. 180M c. 0.35M
b. 2.8M d. 0.18M


____ 29. If the percent by volume is 2.0% and the volume of solution is 250 mL, what is the volume of solute in solution?
a. 0.5 mL c. 5.0 mL
b. 1.25 mL d. 12.5 mL


____ 30. In which of the following is concentration expressed in percent by volume?
a. 10% (v/v) c. 10% (m/m)
b. 10% (m/v) d. 10%


____ 31. If the percent (mass/mass) for a solute is 4% and the mass of the solution is 200 g, what is the mass of solute in solution?
a. 8.0 g c. 80 g
b. 50 g d. 800 g


____ 32. The volume of alcohol present in 620 mL of a 40.0% (v/v) solution of alcohol is ____.
a. 372 mL c. 248 mL
b. 40.0 mL d. 580 mL


____ 33. How many milliliters of alcohol are in 167 mL of an 85.0% (v/v) alcohol solution?
a. 252 mL c. 145 mL
b. 228 mL d. 142 mL


____ 34. In which of the following is concentration expressed in percent by volume?
a. 100% c. 100%
b. 100% d. 100%


____ 35. Which of the following is NOT a colligative property of a solution?
a. boiling point elevation c. vapor pressure lowering
b. supersaturation d. freezing point depression


____ 36. Colligative properties depend upon the ____.
a. nature of the solute c. number of solute particles in a solution
b. nature of the solvent d. freezing point of a solute


____ 37. A solute depresses the freezing point because the solute ____.
a. is colder than the solvent
b. disrupts crystal formation of the solvent
c. tends to sink to the bottom of the solution
d. has bigger molecules than the solvent



answers:
MULTIPLE CHOICE

1. ANS: A DIF: L2 REF: p. 471, p. 472
OBJ: 16.1.1

2. ANS: C DIF: L2 REF: p. 473 OBJ: 16.1.2

3. ANS: D DIF: L2 REF: p. 473 OBJ: 16.1.2

4. ANS: A DIF: L2 REF: p. 473 OBJ: 16.1.2

5. ANS: A DIF: L2 REF: p. 473, p. 474
OBJ: 16.1.3

6. ANS: D DIF: L2 REF: p. 474 OBJ: 16.1.3

7. ANS: A DIF: L2 REF: p. 475 OBJ: 16.1.3

8. ANS: B DIF: L2 REF: p. 474 OBJ: 16.1.3

9. ANS: B DIF: L2 REF: p. 476 OBJ: 16.1.3

10. ANS: D DIF: L3 REF: p. 474 OBJ: 16.1.3

11. ANS: A DIF: L1 REF: p. 476, p. 477
OBJ: 16.1.4

12. ANS: D DIF: L2 REF: p. 476, p. 477
OBJ: 16.1.4

13. ANS: A DIF: L3 REF: p. 476, p. 477
OBJ: 16.1.4

14. ANS: B DIF: L1 REF: p. 480 OBJ: 16.2.1

15. ANS: D DIF: L1 REF: p. 481 OBJ: 16.2.1

16. ANS: D DIF: L1 REF: p. 480, p. 481
OBJ: 16.2.1

17. ANS: B DIF: L2 REF: p. 480 OBJ: 16.2.1

18. ANS: C DIF: L2 REF: p. 480, p. 481
OBJ: 16.2.1

19. ANS: B DIF: L2 REF: p. 481 OBJ: 16.2.1

20. ANS: A DIF: L2 REF: p. 480, p. 482
OBJ: 16.2.1

21. ANS: B DIF: L3 REF: p. 481 OBJ: 16.2.1

22. ANS: A DIF: L3 REF: p. 481, p. 482
OBJ: 16.2.1

23. ANS: D DIF: L3 REF: p. 481, p. 482
OBJ: 16.2.1

24. ANS: C DIF: L1 REF: p. 483 OBJ: 16.2.2

25. ANS: B DIF: L2 REF: p. 483, p. 484
OBJ: 16.2.2

26. ANS: D DIF: L2 REF: p. 483, p. 484
OBJ: 16.2.2

27. ANS: A DIF: L2 REF: p. 483, p. 484
OBJ: 16.2.2

28. ANS: D DIF: L3 REF: p. 483, p. 484
OBJ: 16.2.2

29. ANS: C DIF: L1 REF: p. 485 OBJ: 16.2.3

30. ANS: A DIF: L1 REF: p. 485 OBJ: 16.2.3

31. ANS: A DIF: L1 REF: p. 486 OBJ: 16.2.3

32. ANS: C DIF: L2 REF: p. 485 OBJ: 16.2.3

33. ANS: D DIF: L2 REF: p. 485 OBJ: 16.2.3

34. ANS: B DIF: L2 REF: p. 485 OBJ: 16.2.3

35. ANS: B DIF: L1 REF: p. 487 OBJ: 16.3.1

36. ANS: C DIF: L2 REF: p. 487, p. 488
OBJ: 16.3.1

37. ANS: B DIF: L2 REF: p. 488 OBJ: 16.3.2