`H_(2)S` is bubbled into a `0.2M NaCN` solution which is `0.02M` each in `Ag(CN)_(2)^(Theta)` and `(Cd(CN)_(4)^(2-)`. If `K_(sp)` of `Ag_(2)S` and `CdS` are `10^(-50)` and `7.1 xx 10^(-28)` and `K` instability for `[Ag(CN)_(2)^(Theta)]` and `[Cd(CN)^(2-)underset(4)']` are `1.0 xx 10^(-20)` and `7.8 xx 10^(-18)`, which sulphide will precipitate first?

Answer

CdS;