Question

What is is `K_a` for `HCN(aq) rightleftharpoons H^+(aq) + CN^- (aq)`?

Answer 1

For `"prussic acid"`, `K_a=10^(-9.2)`

Explanation:

Alkali metal salts of cyanide ion, i.e. `K^(+)""^(-)C-=N`, `Na^(+)""^(-)C-=N`, are slightly basic in aqueous solution. Why should this be so?