Question: If $\mathrm{K}_{\mathrm{sp}}$ of $\mathrm{CaF}_{2}$ at $25^{\circ} \mathrm{C}$ is $1.7 \times 10^{-10}$, the combination amongst the following which gives a precipitate of $\mathrm{CaF}_{2}$ is :-
$1 \times 10^{-2} \mathrm{M} \mathrm{Ca}^{2+}$ and $1 \times 10^{-5} \mathrm{M} \mathrm{F}$
$1 \times 10^{-4} \mathrm{M} \mathrm{Ca}^{2+}$ and $1 \times 10^{-4} \mathrm{M} \mathrm{F}^{-}$
$1 \times 10^{-3} \mathrm{M} \mathrm{Ca}^{2+}$ and $1 \times 10^{-5} \mathrm{M} \mathrm{F}^{-}$
$1 \times 10^{-2} \mathrm{M} \mathrm{Ca}^{2+}$ and $1 \times 10^{-3} \mathrm{M} \mathrm{F}^{-}$
Correct Option: , 4
Solution:
