# 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 M b) 0.255 M c) 0.391 M d) 0.301 M e) 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 M b) 0.257 M c) 0.963 M d) 1.475 M e) 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 m b) 0.877 m c) 1.304 m d) 2.709 m e) 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 m b) 0.372 m c) 0.651 m d) 0.798 m e) 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 m b) 1.15 m c) 1.75 m d) 1.89 m e) 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 M b) 2.25 M c) 3.81 M d) 4.22 M e) 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) 0.154 b) 0.732 c) 0.137 d) 0.896 e) 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) 0.055 b) 0.939 c) 0.601 d) 0.017 e) 0.151
9. What is the mole fraction of KI in a solution that is 0.273 m KI?
 a) 0.005 b) 0.273 c) 0.178 d) 0.593 e) 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 m b) 2.46 m c) 4.07 m d) 5.19 m e) 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 m b) 0.524 m c) 0.769 m d) 0.872 m e) 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 M b) 0.415 M c) 0.883 M d) 1.172 M e) 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 M b) 0.503 M c) 0.894 M d) 1.173 M e) 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 mL b) 321 mL c) 493 mL d) 558 mL e) 644 mL