Find out the solubility of Ni(OH)2 in 0.1 M NaOH. Given that the ionic product of Ni(OH)2 is 2×10-15. [2020]
(1)
Ni(OH)2s⇌Ni2+s+2OH-2s
where s is the solubility of Ni(OH)2.
NaOH0.1 M⇌Na+0.1 M+OH-0.1 M
[OH-]=2s+0.1≈0.1 (∵ 2s<<<0.1)
Ionic product of Ni(OH)2=[Ni2+][OH-]2=2×10-15=s(0.1)2
s=2×10-150.1×0.1=2×10-13 M