Name ____________________________________
Ionic Equilibria Homework 2
1. Define the Buffering Capacity
2. Define the Buffering Range
3. You are given 1L of a buffer containing 1.0moles CH3COOH and 1.0 moles of
NaCH3COO. Ka of the acid is 1.8x10-5.
a. What is the pH of this buffer?
b. 0.005 moles of HCl is added, what is the new pH?
c. What is the % change in the pH for the buffer?
4. You are given 1L of deionized water with pH = 7.0, you add 0.005 moles of HCl.
a. What is the new pH?
b. What is the % change in the pH for the water?
5. You are given 1L of a buffer containing 1.5moles CH3COOH and 0.50 moles of
NaCH3COO. Ka of the acid is 1.8x10-5.
a. What is the pH of this buffer?
b. 0.005 moles of HCl is added, what is the new pH?
c. What is the % change in the pH for the buffer?
6. You titrate a weak acid with a strong base is the pH at the equivalence point
a. pH = 7
b. pH > 7
c. pH < 7
7. You titrate a weak base with a strong acid is the pH at the equivalence point
a. pH = 7
b. pH > 7
c. pH < 7
8. You titrate a strong acid with a strong base is the pH at the equivalence point
a. pH = 7
b. pH > 7
c. pH < 7
9. Which of the following indicators would be the best for finding the equivalence
point for the reaction of sodium carbonate and hydrochloric acid?
a. Bromocresol green
b. Phenolphthalein
c. Crystal Violet
10. Which of the following indicators would be the best for finding the equivalence
point for the reaction of sodium hydroxide with hydrochloric acid?
a. Bromocresol green
b. Phenolphthalein
c. Crystal Violet
11. Calculate the solubility of PbCl2 (Ksp = 1.7x10-5)
12. Calculate the solubility of Mg(OH)2 (Ksp = 2.06x10-13)
13. Calculate the solubility of PbCl2 (Ksp = 1.7x10-5) in 0.200M NaCl
14. A 0.50 g sample of AgCl (Ksp = 1.77x10-10) is shaken with 5.0 mL of 6.0 M NH3
until there is no more reaction. The ammonia can react with Ag+(aq) to make a
diammine silver (I) ion
a. write a net ionic reaction that can happen
b. calculate the mass of the AgCl that will remain
15. In the dead sea there is an astonishing 45.9 g/L of Mg2+ in the water. What is
the minimum [OH−] necessary to just begin to precipitate Mg2+ from seawater
assuming Ksp=2.06x10-13)?