Vikas TU
Last Activity: 8 Years ago
The reaction for the dissociation of KCN into the solution is:
KCN + H2O ====> H+ + CN- + OH-
[H+] = [OH-] + [CN-]
[H+]^2 = Ka[HCN] + 10^-14
= 7.2*10^-10*10^-1 + 10^-14
= 72*10^-12 + 0.01*10^-12
[H+] = 72*10^-6 M
pH = -log(72*10^-6) = 4.14