a 25ml sample of 150M hydrofluoric acid is titrated with a 1

a 25ml sample of .150M hydrofluoric acid is titrated with a .150 M NaOH solution. What is the pH at the equivalence point? the Ka of hydrofluoric acid is 3.5x10^-4.

Solution

The acid dissociation constant, Ka, of butanoic acid (C3H7COOH) is defined as:
Ka = [H+][C3H7COO-]/[C3H7COOH]
Since the amount of acid that dissociates is very small in comparison to the
original amount, we can simplify to say: Ka = [H+]