Identify the correct order of solubility in aqueous medium

Options

A. `Na_(2)S gt CuS gt ZnS`
B. `Na_(2)S gt ZuS gt CuS`
C. `ZnS gt Na_(2)S gt CuS `
D. `Na_(2)S gt CuS gt ZnS`

Answer

b,c

Explanation

Higher the `K_(sp)` of sulphides more is the solubility in aqueous medium
In the salt analysis `K_(sp)` sulphides increases from group `1` of salt anlysis to group `IV` of salt anlysis `Cu^(+2)` ion is in group II whereas `Zn^(+2)` is in group IV of salt analysis
`:.` Solubility of `ZnS gt CuS`
since the `K_(sp)` of sulphides of sodium is the bighest therefore it is highly soluble
Hence the answer is (b) i.e. solubility of `Na_(2)S gt ZnS CuS`