6. What is the pH of a buffer system that contains 0.200 Mhydrocyanic acid (HCN) and 0.150 M sodium cyanide (NaCN)? The pk of hydrocyanic acid is 9.31. (10.78)] a. Before you do any calculations, estimate the pH of this buffer: . 8 ng w10 b. Calculate the pH of this buffer system to two places past the decimal point. 7. A solution of 0.10 MCH;COOH has a [H,O*] = 0013 M. What percent of this weak acid is dissociated? [~10.54] %3D