Question

Determine the equilibrium constant for a 0.10M phenol (HC6H5O) solution that has a pH of 5.43 at 25 degrees C. What is the degree of ionization of this weak acid? Why is the pH value important for this problem?

Answer 1

Let phenol = HP
pH = -log(H^+). You know pH, solve for H^+
.....................HP.........H^+ + P^-

K = (H^+)(P^-)/(HP)
From the pH you get H^+ and P^- and HP. Substitute into the K expression and solve for K.
Post your work if you get stuck.

Answer 2

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