pH of a saturated solution of `Ca(OH)_2` is 9. The solubility product `(K_(sp))" of "Ca(OH)_2` is

Options

A. `0.5 xx 10^(-10)`
B. `0.5 xx 10^(-15)`
C. `0.25 xx 10^(-10)`
D. `0.125 xx 10^(-15)`

Answer

B

Explanation

pH of the saturated solution of `Ca(OH)_2=9`
pOH of the saturated solution of `Ca(OH)_(2)=5`
`rArr [OH^-]=10^(-5) " "(pH +pOH =14)`
`Ca(OH)_(2) rArr Ca^(2+) +2OH^(-)`
`" s 2r"`
`" "1//2 xx10^(-5)" "10^(-5)`
`K_(sp)=[Ca^(2+)] [OH^(-)]^2 =[1//2 xx 10^(-5)] [10^(-5)]^2 =0.5 xx 10^(-15)`