Equal volume of the follwing $Ca^{2+}$ and $F^-$ solutions are mixed. In which of the follwing solutions will precipitation occur?

Question

[$K_{sp}$ of $CaF_2$ = $1.7 \times 10^{-10}$] 

1. $10^{-2} of Ca^{2+} + 10^{-5} MF^-$ 

2. $10^{-3} of Ca^{2+} + 10 ^{-3} MF^-$ 

3. $10^{-4} of Ca^{2+} + 10 ^{-2} MF^-$ 

4. $10^{-2} of Ca^{2+} + 10 ^{-3} MF^-$

Select the correct answer using codes given below.

 

(a) In 4 only

(b) In 1 and 2

(c) In 3 and 4

(d) In 2, 3 and 4