Homework Chapter 14


14.1 Dissociation

1. For each of the following write the dissociation equation, indicate the number of moles of each reactant and product, and the total number of moles of ions produced.

a) 1 mol of ammonium chloride soln
b) 0.5 mol of ammonium chloride
c) 1 mol of sodium sulfide
d) 0.5 mol of barium nitrate
e) 0.5 mol of strontium nitrate, Sr(NO3)2
f) 2 mol of KI
g) 1 mol of NaNO3
h) 4 mol of MgCl2
i) 2 mol of Na2SO4

2. Using table 14-1, predict if each of the following is soluble or insoluble:

a) KCl
b) NaNO3
c) AgCl
d) BaSO4
e) Ca3(PO4)2
f) Pb(ClO3)2
g) (NH4)2S
h) PbCl2 in cold water
i) FeS
j) Al2(SO4)3

14.2 Net Ionic Equations

For each of the following reactions, write the chemical equation (be sure that your chemical formulas are correct), balance the equation, write the ionic equation (indicating if a precipitate forms by checking table 14-1), and, if appropriate, the net ionic equation:

a) solution of magnesium acetate and solution of strontium chloride are combined soln
b) solution of mercury (II) chloride and a solution of potassium sulfide are combined
c) a solution of sodium carbonate and a solution of calcium chloride are combined
d) a solution of copper (II) chloride and a solution of ammonium phosphate are combined
e) a solution of copper (II) chloride and a solution of lead (II) nitrate are combined

14.3 Ionization

1. What determines whether a molecular compound will be ionized in a polar solvent?

2. a) How is the hydronium ion formed when a compound like HCl dissolves in water?
b) What is the net charge on the hydronium ion?

3. Explain why HCl is a strong electrolyte and HF is a weak electrolyte.

4. Distinguish between ionization and dissociation.

5. Distinguish between the use of the terms strong and weak versus dilute and concentrated when used to describe electrolyte solutions.

14.4 Freezing Point Depression

1. A solution consists of 10.3 g of the non electrolyte glucose, C6H12O6, dissolved in 250. g of water. What is the freezing point depression of the solution? soln

2. Experimentally, the freezing point of an aqueous solution of glucose is found to be -0.3250C. What is the molal concentration of this solution? soln

3. If 0.500 mol of a non electrolyte solute are dissolved in 500.0 g of ether, what is the freezing point of the solution? soln

4. The freezing point of an aqueous solution that contains a non electrolyte is -9.00C.
a) What is the freezing point depression of the solution?
b) What is the molal concentration of the solution? soln

5. Determine the freezing point of a 1.50 m solution of sucrose, C12H22O11, in water. soln

6. Given 0.01m aqueous solutions of each of the following, arrange the solution in order of increasing change in the freezing point of the solution:
a) NaI
b) CaCl2
c) K3PO4
d) C6H12O6 (glucose) soln

14.5 Boiling Point Elevation

1. A solution contains 50.0 g of sucrose, C12H22O11, a non electrolyte, dissolved in 500.0 g or water. What is the boiling point elevation? soln

2. A solution contains 450.0 g of sucrose, C12H22O11, a non electrolyte, dissolved in 250. g of water. What is the boiling point of the solution? soln

3. If the boiling point elevation of an aqueous solution containing a nonvolatile electrolyte is 1.020C, what is the molality of the solution? soln

4. The boiling point of an aqueous solution containing a nonvolatile electrolyte is 100.750C.
a) What is the boiling point elevation?
b) What is the molality of the solution? soln

5. Determine the boiling point of a 2.5m solution of glucose, C6H12O6, in water. soln

14.6 Osmotic Pressure

1. a)Why does the level of the more concentrated solution rise when two solutions of different concentrations are separated by a semi permeable membrane?
b) When does the level of the solution stop rising?
c) When the level stops rising, what is the net movement of water molecules across the membrane?

14.7 Electrolytes and Colligative Properties

1. What is the expected freezing point depression for a solution that contains 2.0 mol of magnesium sulfate dissolved in 1.0 kg or water? soln

2. What is the expected boiling point elevation of water for a solution that contains 150. g of sodium chloride dissolved in 1.0 kg of water? soln

3. The freezing point of an aqueous sodium chloride solution is -20.00C. What is the molality of the solution? soln

4. Determine the expected boiling point of a solution made by dissolving 25.0g of barium chloride in 0.150 kg of water. soln