The volume of water needed to dissolve `1mg` of `PbSO_(4) (K_(sp) = 1.44 xx 10^(-8), Mw of PbSO_(4) = 303g)` at `25^(@)C` is

Options

A. `80mL`
B. `43mL`
C. `27.5mL`
D. 10mL`

Answer

C

Explanation

`S = (K_(sp))^(1//2) = (1.44 xx 10^(-8))^(1//2)`
`= 12 xx 10^(-5)`
`=303 xx 12 xx 10^(-5)gL^(-1)`
` = 3636 xx 10^(-5)gL^(-1)`
`= 0.03636 gL^(-1) = 0.03636 mg mL^(-1)`
`V_(H_(2)O) = (1)/(0.03636) = (10^(5))/(3636) = 27.5mL`