PRACTICE PROBLEMS

Solution Concentrations and Conversions

1. What is the molarity of a solution that is prepared by dissolving 0.178 moles of NaCl in enough water to make 455 mL of solution?
a) 0.178 Mb) 0.255 Mc) 0.391 M d) 0.301 Me) 0.775 M
2. What is the molarity of a solution prepared by dissolving 25.7 g NaCl in enough water to make 153 mL of solution?
a) 0.0257 Mb) 0.257 Mc) 0.963 M d) 1.475 Me) 2.87 M
3. What is the molality of a solution prepared by dissolving 0.785 moles of KI in 895 g of water?
a) 0.102 mb) 0.877 mc) 1.304 m d) 2.709 me) 3.887 m
4. What is the molality of a solution prepared by dissolving 25.4 g KI in 963 g of water?
a) 0.159 mb) 0.372 mc) 0.651 m d) 0.798 me) 1.016 m
5. What is the molality of a 1.75 M solution of Na2CO3 in water? The density of this solution is 1.112 g/mL.
a) 0.995 mb) 1.15 mc) 1.75 m d) 1.89 me) 2.87 m
6. What is the molarity of a 2.55 m solution of KI in water? The density of this solution is 1.254 g/mL.
a) 1.17 Mb) 2.25 Mc) 3.81 M d) 4.22 Me) 5.21 M
7. What is the mole fraction of NaCl in a solution prepared by dissolving 1.54 moles of NaCl in 9.73 moles of water?
a) 0.154b) 0.732c) 0.137 d) 0.896e) 0.443
8. What is the mole fraction of NaCl in a solution prepared by dissolving 15.11 g NaCl in 275.2 g H2O?
a) 0.055b) 0.939c) 0.601 d) 0.017e) 0.151
9. What is the mole fraction of KI in a solution that is 0.273 m KI?
a) 0.005b) 0.273c) 0.178 d) 0.593e) 0.872
10. What is the molality of NaCl in an aqueous solution in which the mole fraction of NaCl is 4.24 x 10-2?
a) 1.17 mb) 2.46 mc) 4.07 m d) 5.19 me) 5.93 m
11. What is the mass percentage of sucrose, C12H22O11 in a solution prepared by dissolving 5.17 g of sucrose in 89.74 g of water?
a) 11.15%b) 8.99%c) 7.18% d) 5.76%e) 5.45%
12. What is the molality of a 15.21% C12H22O11 solution?
a) 0.253 mb) 0.524 mc) 0.769 m d) 0.872 me) 1.908 m
13. What is the percent by mass of KCl in a 1.53 m KCl solution?
a) 8.15%b) 6.17%c) 5.98% d) 10.2%e) 19.3%
14. What is the mole fraction of NaI in a solution that is 17.85% NaI by mass?
a) 1.17 x 10-3 b) 2.55 x 10-2 c) 4.18 x 10-2
d) 8.85 x 10-2 e) 1.92 x 10-1
15. What is the percent by mass of HCl in a solution in which the mole fraction of HCl is 1.48 x 10-2?
a) 15.45%b) 10.22%c) 8.19% d) 4.16%e) 2.95%
16. What is the molarity of NaCl in a solution that is 5.02% NaCl by mass? The density of this solution is 1.028 g/mL.
a) 0.113 Mb) 0.415 Mc) 0.883 M d) 1.172 Me) 1.398 M
17. What is the percent by mass of CaCl2 in a 2.78 M CaCl2 solution? The density of the solution is 1.165 g/mL.
a) 26.5%b) 35.8%c) 47.2% d) 59.6%e) 64.7%
18. What is the mole fraction of HCl in a 3.48 M HCl solution? The density of the solution is 1.058 g/mL.
a) 1.08 x 10-3 b) 2.24 x 10-3 c) 1.21 x 10-2
d) 6.31 x 10-2 e) 1.15 x 10-1
19. What is the molarity of a NaCl solution in which the mole fraction of NaCl is 9.11 x 10-3? The density of the solution is 1.016 g/mL.
a) 0.217 Mb) 0.503 Mc) 0.894 M d) 1.173 Me) 1.767 M
20. How many milliliters of a 0.20 M NaOH solution would be required in order to have 5.15 g NaOH?
a) 203 mLb) 321 mLc) 493 mL d) 558 mLe) 644 mL
QUICK ANSWERS

1 c    2 e    3 b    4 a    5 d    6 b    7 c    8 d    9 a    10 b

11 e    12 b    13 d    14 b    15 e    16 c    17 a    18 d    19 b    20 e

This page was last modified Wednesday February 10, 1999