Question

$M(OH{)}_x$ has $K_{sp}=4\times 10^{-12}$ and solubility $10^{-4}M.$ Hence, $x$ is:

• A. 1
• B. 2
• C. 3
• D. 4

Answer 1

Answer: (B)

$M(OH)\to \underset{S}{M^{x+}}+\underset{xs}{xO{H}^{-}}$
$\therefore (S)(xS{)}^x=K_{sp}$
$x^x{S}^{x+1}=4\times 10^{-12}$
$x^x{\left(10^{-4}\right)}^{x+1}=4\times 10^{-12}$
$\therefore x=2$