AgCN ⇌ Ag+ + CN−
Ksp = [Ag+][CN−] = 6 × 10−17
Ni(OH)2 ⇌ Ni2+ + 2OH-
Ksp = [Ni2+][OH−] 2 = 2 × 10−15
Let [Ag+] = S,then [CN−] = S1
Let [Ni2+] = S2,then [OH−] = 2S2
∴ From eq. (i)
S1 × S1 = 6 × 10−17
S12 = 6 × 10−17
S1 = 7.8 × 10−9
∴ From eq. (ii)
(S1) × (2S2)2 = 2 × 10−15
4S23 = 2 × 10−15
S23 = \(\frac{2\times10^{-15}}{4}\)
= 0.5 × 10−15
or
S2 = 0.58 × 10−4
Since solubility of Ni(OH)2 is more than AgCN, so, Ni(OH)2 is more soluble than AgCN.
