Chemistry Name :
Test review : Ch. 15 and 16 - Problems Date :
A. Henry's Law
1. Carbon dioxide has a solubility of 0.737 g/L at a temperature of 0.0 ºC and 2.2 atm. What will the solubility be at .50 atm at the same temperature?
2. Nitrogen has a solubility of 0.080 g/L at 20 ºC and 1.0 atm of pressure. What would its solubility be at 1.5 atm and 20 ºC?
B. Molarity
3. What is the molar concentration of a solution which contains 3.50 g of sodium chloride in 450.0 mL of solution?
4. What is the molar concentration of a solution which contains 0.55 g of magnesium sulfate in 1.50 L of solution?
5. What is the molarity of a solution which contains 0.55 g of lithium chloride in 420.0 mL of solution?
6. How many grams of calcium chloride are there in 350 mL of a 0.050 M solution of calcium chloride?
C. Dilution
7. 800.0 mL of a 0.30 M barium chloride solution is diluted to a volume of 1500.0 mL. What is the molarity of the new solution?
8. A student has 450.0 mL of a 0.20 molar sodium chloride solution. She needs a 0.065 M solution. To what volume should she dilute the original solution?
9. What are the concentrations of all the ionic species ion a mixture formed by combining 500.0 mL of 0.50 M
lithium sulfate and 120.0 mL of 0.60 M lithium phosphate?
D. Percent concentration
10. What is the percent by volume concentration of a solution containing 80.0 mL of acetone in 8000.0 mL of solution?
11. What is the percent(m/v) concentration of a solution made by dissolving 22.0 g of sucrose in 400.0 mL of solution?
12. How many grams of sucrose are there in 350.0 mL of the above solution of sucrose?
E. Molality
13. What is the molal concentration (molality) of a solution which contains 1.55 g of potassium chloride in 500.0 g of water?
14. How many grams of potassium chloride are needed to make .60m solution in 850.0 g of water?
F. Mole fraction
15. What is the mole fraction of glucose and of water in a solution consisting of 0.45 mol of glucose in 3.50 mol of water?
16. What is the mole fraction of a solution consisting of 60.0 g of glucose (gmm=180.18g) and 1.00 Kg of water?
G. Changes in boiling or freezing point
17. What will the boiling point of a solution be if it was formed by adding 120.0 g of glucose to 550.0 g of water? (Assume 1 atm. of pressure)(Kb = 0.512 ºC/m)
18. What will the freezing point be of a solution formed by adding 50.0 g of magnesium nitrate to 450.0 g of water? (Kf = 1.86 ºC/m)
19. What is the boiling point of the coolant in an automobile engine that is 70.0 % ethylene glycol (HOCH2CH2OH, FW= 62.08 g/mol)( Kb for water = 0.512 ºC/m)?
H. Calculation of molecular mass.
20. If 2.54 g of a nonvolatile molecular solute is dissolved in 300.0 g of water, the freezing point of the solution falls to -0.338 ºC. What is the molecular mass of this solute?(Kf for water is 1.86 ºC/m).
21. A solution contains 850.0 g of a nonvolatile molecular solute in 600.0 g of water causing the solution to have a boiling point of 102.25 ºC. What is the molecular mass of this solute?(Kb for water is 0.512 ºC/m)
Answers : 1. .17g/L 2. .12 g/L 3. .133M 4. .0030 M 5. .031M 6. 1.9 g 7. .16M
8. 1400mL 9. 1.2 M Li+, 0.40 M SO42- , 0.12 M PO43- 10. 1.00% 11. 5.50% (g/mL) 12. 19.3g 13. .0416m 14. 38 g 15. .11 glucose, .886 water 16. .00597 glucose, .994 water 17. 100.620 ºC 18. -4.18 ºC 19. 119.2 ºC (about 247 ºF) 20. 46.5 g/mole 21. 322 g/mole