Question

A saturated solution of Pb(IO3)2 in pure water has a lead ion concentration of 5.0 x 10-5 Molar. What is the Ksp value of Pb(IO3)2? A. 1.0 x 10-5 Molar B. 5.0 x 10-5 Molar C. 1.0 x 10-13 Molar D. 2.5 x 10-13 Molar E. 5 x 10-13 Molar

Answer 1

Answer:

Option (E) is correct

Explanation:

Solubility equilibrium of $Pb(IO_{3})_{2}$ is given as follows-

                   $Pb(IO_{3})_{2}\rightleftharpoons Pb^{2+}+2IO_{3}^{-}$

Hence, if solubility of $Pb(IO_{3})_{2}$ is S (M) then-

                             $[Pb^{2+}]=S(M)$ and $[IO_{3}^{-}]=2S(M)$

Where species under third bracket represent equilibrium concentrations

So, solubility product of $Pb(IO_{3})_{2}$ , $K_{sp}=[Pb^{2+}][IO_{3}^{-}]^{2}$

Here, $[Pb^{2+}]=S(M)=5.0\times 10^{-5}M$

So, $[IO_{3}^{-}]=2S(M)=(2\times 5.0\times 10^{-5})M=1.0\times 10^{-4}M$

So, $K_{sp}=(5.0\times 10^{-5})\times (1.0\times 10^{-4})^{2}=5.0\times 10^{-13}$

Hence option (E) is correct