Question

Will $Ca{F}_2$ be precipitated?

• A. Yes
• B. No
• C. Data insufficient
• D. None of these

Answer 1

The correct option is B No

$\left[C{a}^{+2}\right]=\left[F^{-}\right]=\frac{{10}^{-4}}{2}=5\times {10}^{-5}$

The ionic product is $\left[C{a}^{2+}\right][F^{-}{]}^2=(5\times {10}^{-5}\left)\right(5\times {10}^{-5}{)}^2=1.255\times {10}^{-13}$.

But $K_{sp}=1.6\times {10}^{-10}$

Since the value of the ionic product is less than the value of the solubility product, no precipitation will occur.