A solution of `CaF_(2)` is found to contain `4 xx 10^(-4)M` of `F^(Theta)`, `K_(sp)` of `CaF_(2)` is

Options

A. `3.2 xx 10^(-11)`
B. `0.8 xx 10^(-11)`
C. `6.4 xx 10^(-11)`
D. `32 xx 10^(-11)`

Answer

A

Explanation

`{:(CaF_(2)hArr,Ca^(2+),2F^(Theta)),(,x,2x):}`
Total concentration of `[F^(Theta)] = 4 xx 10^(-4)M`
`:.2x = 4 xx 10^(-4)`
`x = 2 xx 10^(-4)`
`:. K_(sp) = 4x^(3) = 4 xx (2xx 10^(-4))^(3) = 3.2 xx 10^(-11)`