# Chapter 16 Lecture Problems

## Strong Acid-Strong Base Titration

1. Start with 50.0 mL of 0.100 M HCl, Calculate pH
1. Add 1 mL 0.200 M NaOH, Calculate pH
2. Add 5 mL 0.200 M NaOH, Calculate pH
3. Add 10 mL 0.200 M NaOH, Calculate pH
4. Add 15 mL 0.200 M NaOH, Calculate pH
5. Add 20 mL 0.200 M NaOH, Calculate pH
6. Add 25 mL 0.200 M NaOH, Calculate pH
7. Add 26 mL 0.200 M NaOH, Calculate pH
8. Add 30 mL 0.200 M NaOH, Calculate pH
9. Add 50 mL 0.200 M NaOH, Calculate pH

2. Summerize results

 mL 0.100 M HCl mL 0.200 M NaOH pH 50 0 1.00 50 1 1.03 50 5 1.14 50 10 1.30 50 15 1.51 50 20 1.84 50 25 7.00 50 26 11.42 50 30 12.10 50 50 12.70

3. Show graph in spreadsheet.

4. Solutions

## Buffer Calculations

1. Calculate for a 0.1 M acetic acid/0.1 M sodium acetate buffer. Solution

2. Effect of adding a base to a generic weak acid. (mathcad)

3. Add 0.05 moles of sodium hydroxide to 1 liter of acetic acid buffer. (Solution)

4. Add 0.05 moles of sodium hydroxide to 1 liter of water.

5. Formic acid buffer
1. 10.0 mL of 1.0 M formic acid is mixed with 1.00 g of sodium formate and diluted to 250.0 mL.
2. Add 5.0 mL of 1.0 M sodium hydroxide to the formic acid/sodium formate solution.
3. Add 5.0 mL of 2.0 M hydrochloric acid to the formic acid/sodium formate solution.
4. Solutions

6. Graph results of adding acid or base to a buffer with spreadsheet

## Titration of a weak acid

1. Calculate for 100.0 mL of 0.1 M acetic acid solution.

1. Add 1 mL of 0.1 M sodium hydroxide.

2. Add 10 mL of 0.1 M sodium hydroxide.

3. Add 50 mL of 0.1 M sodium hydroxide.

4. Add 75 mL of 0.1 M sodium hydroxide.

5. Add 100 mL of 0.1 M sodium hydroxide.

6. Add 110 mL of 0.1 M sodium hydroxide.

2. Graph results with Spreadsheet

3. Solutions

## Solubility Equlibrium Problems

1. Molar Solubility. 9.3x10-3 g of CaCO3 dissolves in 1 L of water. What is the "molar solubility" Solutions

2. What is Ksp for CaCO3? Solutions

3. How much AgCl will dissolve in 500 mL of water? Ksp = 1.56 x 10-10 Solutions

4. How much PbCl2 will dissolve in 500 mL of water? Ksp = 1.6 x 10-5. Solutions

5. Given Ksp = 1.5 x 10-11 for Mg(OH)2
1. Calculate the mass of Mg(OH)2 that will dissolve in 250 mL of water.
2. Calculate the mass of Mg(OH)2 that will dissolve in 250 mL of water with the pH buffered to 13.
3. Calculate the mass of Mg(OH)2 that will dissolve in 250 mL of water with the pH buffered to 4.
4. Solutions

6. For AgCl, Ksp = 1.56 x 10-10
1. What is the solubility in water
2. What is the solubility in 0.10 M NaCl
3. What is the solubility in 1.0 M NaCl
4. What happens when 50 mL of 1.0 x10-4 M NaCl is added to 50 mL of 1.0x10-6 M AgNO3.
5. Increase the concentration of NaCl to 0.50 M and repeat.
6. Solutions

7. For PbCl2, Ksp = 1.6 x 10-5
1. What is the solubility in water
2. What is the solubility in 0.10 M NaCl
3. What is the solubility in 1.0 M NaCl
4. What happens when 50 mL of 0.20M NaCl is added to 50 mL of 1.0x10-4 M Pb(NO3)2.
5. Increase the concentration of NaCl to 2.0 M and repeat.
6. Solutions

8. Given a solution containing Ba2+ and Fe2+, Start at pH 1 and adjust the pH so that:
1. The first ion begins to precipitate
2. The second ion begins to precipitate
3. How much of the first has precipitated at this point?
4. How much of the second ion has precipitated at pH 14?
5. Solutions