Question

The solubility product of chalk is $9.3\times 10^{-8}$ Calculate its solubility in gram per liter.

• A. $0.3040$ gram/liter
• B. $0.0304$ gram/liter
• C. $2.0304$ gram/liter
• D. $4.0304$ gram/liter

Answer 1

Answer: (B)

$CaC{O}_3\rightleftharpoons C{a}^{2+}+C{O}_3^{2-}$

Let the solubility of $CaC{O}_3$ be $S$ mole per liter

$\therefore K_{sp}=\left[C{a}^{2+}\right]\left[C{O}_3^{2-}\right]=S.S$

$\therefore S=\sqrt{K_{sp}}=\sqrt{9.3\times 10^{-8}}=0.000304$ mol / liter

Solubility in $g/l=$ mole/liter $\times$ Molecular weight of $CaC{O}_3$

$=0.000304\times 100=0.0304$ gram/liter