Question

The solubility product for a salt of the type AB is 4 × 10^–8. What is the molarity of its standard solution?

(1) 4 × 10^–4 mol/L 

(2) 2 × 10^–4 mol/L

(3) 16 × 10^–16 mol/L 

(4) 2 × 10^–16 mol/L

Comments

Equilibrium, solubility equilibria

Answer 1

Ans: (2) 2 × 10^–4 mol/L

Sol. For salt AB

$K_{sp}=(s)^2\implies s=\sqrt{K_{sp}}$

$s=\sqrt{4\times10^{-8}}=2\times10^{-4}M$

Answer 2

4×10^-4mol/litre