Question

One litre of saturated solution of $CaC{O}_3$ is evaporated to dryness, $7.0$g of residue is left. The solubility product for $CaC{O}_3$ is:

• A. $4.9\times {10}^{-3}$
• B. $4.9\times {10}^{-5}$
• C. $4.9\times {10}^{-9}$
• D. $4.9\times {10}^{-7}$

Answer 1

The correct option is A $4.9\times {10}^{-3}$

Molar mass of $CaC{o}_3=100$

Number of Moles $=7/100$

Concentration $=\frac{Mol}{L}$

$=\frac{7}{100\left(I\right)}$ $0.0699M$

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

$Ksp=\left[C{a}^{2+}\right]\left[C{O}_3^{2-}\right]$

$=\left[0.0699\right]\left[0.0699\right]$

$=4.89\times {10}^{-3}$