A 1.45 L buffer solution consists of 0.111 M butanoic acid and 0.281 M sodium butanoate. Calculate the pH of the solution following the addition of 0.078 moles of NaOH. Assumr that any contribution of the NaOH to the volume of the solution negligble. The ka of butanoic acid is 1.52x10^-5.
Ph= __________-