The solubility of a saturated solution of calcium fluoride is $2 imes 10^{-4}$ moles per litre. It

Question

The solubility of a saturated solution of calcium fluoride is $2 	imes 10^{-4}$ moles per litre. Its solubility product is\

Professor PC Thomas Classes · Answer

(d) : For $\mathrm{CaF}_{2}$, decomposition is as follows : $$ \mathrm{CaF}_{2} ightarrow \mathrm{Ca}^{2+{ }^{2}}+\underset{2 s}{2 \mathrm{~F}^{-}} $$ $\Rightarrow \quad K_{s p}=\left[\mathrm{Ca}^{2+}ight]\left[\mathrm{F}^{-}ight]^{2}=s 	imes(2 s)^{2}$\ or $\quad K_{s p}^{s p}=4 s^{3} \Rightarrow K_{s p}=4 	imes\left(2 	imes 10^{-4}ight)^{3} \Rightarrow K_{s p}=32 	imes 10^{-12}$\