On adding `0.1M` solution each of `Ag^(+)`, `Ba^(2+)`, `Ca^(2+)` ions in a `Na_(2)SO_(4)` solution, the species first precipitated is `(K_(s)(CaSO_(4))=10^(-6)`, `K_(s)(BaSO_(4))=10^(-11)`, `K_(s)(Ag_(2)SO_(4))=10^(-5)` :

Options

A. `Ag_(2)SO_(4)`
B. `BaSO_(4)`
C. `CaSO_(4)`
D. All of these

Answer

B

Explanation

`K_(s)` for `Ag_(2)SO_(4)=[Ag^(+)][SO_(4)^(2-)]`
`:. [SO_(4)^(-2)]` required for precipitation should be greater than `(K_(s))/([Ag^(+)]^(2))=(10^(-5))/((0.1)^(2))=10^(-3)M`.
Similarly, `[SO_(4)^(2-)]` for precipitation of `BaSO_(4)` should be greater than `(K_(s))/([Ba^(2+)])=(10^(-11))/(0.1)=10^(-10)M`
`[SO_(4)^(2-)]` for precipitation of `CuSO_(4)` should be greater than `(K_(s))/([Cu^(2+)])=(10^(-6))/(0.1)=10^(-5)M`
The minimum `[SO_(4)^(2-)]` concentration required for precipitation in for `BaSO_(4)`.