Solubility product constant `(K_(sp))` of salts of types `MX, MX_2 and M_3X` at temperature 'T' are `4.0 xx 10^(-8), 3.2 xx 10^(-14) and 2.7 xx 10^(-15)`, respectively. Solubilities `("mol. Dm"^(-3)` of the salts at temperature 'T' are in the order

Options

A. `MX gt MX_2 gt M_3X`
B. `M_3X gt MX_2 gt MX`
C. `MX_2 gt M_3X gt MX`
D. `MX gt M_3X gt MX_2`

Answer

D

Explanation

Solubility of MX, `s_1=sqrt(4xx10^(-8))=2xx10^(-4)`
Solubility of `MX_2` ,
`s_2=(K_(sp)/4)^(1//3) =((3.2xx10^(-14))/4)^(1//3)=2xx10^(-5)`
Solubility of `M_3X, s_3=((2.7xx10^(-15))/27)^(1//4)=10^(-4)`
`s_1 > s_3 > s_2 rArr MX > M_3X > MX_2`