Acid-Base Equilibria (Worksheet)

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Work in groups on these problems. You should try to answer the questions without referring to your textbook. If you get stuck, try asking another group for help.

Q1

Calculate the equilibrium concentrations and pH for a 0.20 M proprionic acid solution. $$K_a = 1.3 \times 10^{-5}$$

Q2

Calculate the equilibrium concentrations and pH for a 0.20 M carbonic acid solution. Compare the answer to problem 1. Note which has the higher $$K_a$$ and lower pH. $$K_a = 4.2 \times 10^{-7}$$

Q3

Calculate the $$K_a$$ for a 0.3 M solution of $$HA$$ (weak acid) if the pH = 3.65

Q4

Calculate the pH for a 0.2 M pyridine solution. $$K_b = 2.0 \times 10^{-9}$$

Q5

Calculate the pH of a $$0.34 M HCl$$ solution.