Need some assistance: 2a) Calculate the pH of a buffer solution that is 0.250 M in HCN and 0.170 M in KCN. For HCN, Ka = 4.9 x 10^-10 (pka = 9.31). Use the equilibirum approach to calculate this pH. 2b) Repeat the pH calculations for the previous question, but this time use the Henderson-Hasselbalch approach.