Calculate the pH:
a) Of a buffer solution consisting of 0.50 M CH3COOH and 0.50 M CH3COONa
b) After adding 0.020 mol of solid NaOH to 1.0 L of the buffer solution in part (a)
c) After adding 0.020 mol of HCl to 1.0 L of the buffer solution in part (a) Ka of CH3COOH = 1.8 × 10-5 (Assume the additions cause negligible volume changes)