AP Chemistry Review - Applications of Aqueous Equilibria

Which of the following pairs of compounds could create a suitable buffer system?
1. sodium chloride and sodium hydroxide
2. sodium sulfate and sodium hydroxide
3. sodium acetate and acetic acid
4. carbonic acid and sodium chloride
5. ammonia and potassium hydroxide
What is the pH of a solution that is 0.50 M in propanoic acid and 0.40 M in sodium propanoate. (K_a for propanoic acid = 1.3 x 10^-5)
1. 0.097
2. 4.98
3. 0.47
4. 4.79
5. -4.98
A buffer solution is prepared that is 0.50 M in propanoic acid and 0.40 M in sodium propanoate with a solution volume of 1.00 liters. (K_a for propanoic acid = 1.3 x 10^-5). What is the pH of the solution when 0.040 mol of HCl(g) is added to the solution? Assume no change in solution volume.
1. 4.97
2. 4.67
3. 4.91
4. 4.71
5. 4.77
A buffer solution is prepared that is 0.50 M in propanoic acid and 0.40 M in sodium propanoate with a solution volume of 1.00 liters. (K_a for propanoic acid = 1.3 x 10^-5). What is the pH of the solution when 0.060 mol of NaOH(s) is added to the solution? Assume no change in solution volume.
1. 3.97
2. 4.67
3. 4.77
4. 4.91
5. 4.97
Suppose that 0.250 liters of a buffer solution that contains 0.225 M acetic acid and 0.225 M sodium acetate. What would be the pH change if 30.0 mL of 0.100 M HCl is added to this buffer? Assume volumes are additive. K_a for acetic acid is 1.8 x 10 ^-5.
1. 4.70 to 4.78
2. 4.74 to 4.70
3. 4.74 to 4.82
4. 5.40 to 7.68
5. 6.40 to 4.56
What is the pH of a buffer solution consisting of 0.150 mol of NH₃ plus 0.250 mol of NH₄Cl in enough water to make 0.750 liter of solution. K_b = 1.81 x 10^-5.
1. 9.036
2. 4.963
3. 2.721
4. 11.279
5. 8.547
80.0 mL of a buffer solution contains 0.169 M NH₃ and 0.183 M NH₄Cl. If you add 10.0 mL of 0.100 M HCl, what will be the pH? K_b = 1.81 x 10^-5. Assume additive volumes.
1. 9.161
2. 4.963
3. 2.721
4. 11.279
5. 7.908
K_a for HNO₂ is 4.5 x 10^-4, calculate the pH of a buffer solution made by mixing 0.225 mol of HNO₂ and 0.450 mol of NaNO₂ in enough water to make 0.400 liter of solution.
1. 3.51
2. 3.65
3. 3.90
4. 5.72
5. 2.98
Suppose you are given 0.50 liter of 0.500 M acetic acid, and 0.50 liter of 0.250 M sodium acetate. What is the maximum volume of buffer solution that you can make if the buffer must have a pH of 4.58? K_a for acetic acid is 1.8 x 10^-5.
1. 0.50 liter
2. 0.287 liter
3. 0.91 liter
4. 0.87 liter
5. 0.78 liter
A chemist desires to create a buffer solution beginning with 1.00 liter of 0.200 M NH₃. How many moles of gaseous HCl must be introduced in order to produce a buffer of maximum capacity. Assume no increase in solution volume.
1. 0.100 mol HCl
2. 0.200 mol HCl
3. 0.300 mol HCl
4. 0.500 mol HCl
5. None - the solution is already buffered
The K_sp of BaSO₄ is 1.5 x 10^-9. What is the molar concentration of Ba²⁺(aq) in a saturated solution of BaSO₄?
1. 2.25 x 10^-18 M
2. 2.45 x 10^-5 M
3. 6.7 x 10^-15 M
4. 3.9 x 10^-5 M
5. 1.7 x 10^-2 M
The K_sp of BaSO₄ is 1.5 x 10^-9. How many grams of BaSO₄ can be dissolved in 1000. liters of solution?
1. 0.085 g
2. 170 g
3. 9.0 g
4. 2.3 g
5. 39 g
Calculate the K_sp of Ba(OH)₂ given the fact that the solubility of Ba(OH)₂ in water is 4.6 g per 0.250 liter.
1. 5.0 x 10^-3
2. 1.2 x 10^-2
3. 1.1 x 10^-1
4. 2.0 x 10^-7
5. 1.5 x 10^-4
The image above shows the titration of a:
1. strong acid with a strong base
2. Strong acid with a weak base
3. Weak acid with a strong acid
4. Weak acid with a strong base
5. weak base with a strong base
200.0 mL of 0.200 M HCl is titrated with 0.050 M NaOH. What is the pH after the addition of 100. mL of the NaOH solution?
1. 1.45
2. 0.76
3. 0.93
4. 1.03
5. 0.82
50.0 mL of 0.100 M NH₃ is titrated with 0.025 M HCl. What is the pH of the solution after 100.0 mL of HCl has been added? K_b for NH₃ 1.81 x 10^-5.
1. 4.74
2. 9.26
3. 12.45
4. 8.99
5. 10.90