Amongst the following hydroxides, the one which has the lowest value of `K_(sp)` is:

Options

A. `Ba(OH)_(2)`
B. `Mg(OH)_(2)`
C. `Be(OH)_(2)`
D. `Ca(OH)_(2)`

Answer

C

Explanation

All these compounds have identical composition. Thus, `K_(sp)` is directely related to the solubility of the compound. Since the solubility of the group 2 hydroxides increases on moving down the group, the order of solubility of these hydroxides is `Ba(OH)_(2)gtCa(OH)_(2)gtMg(OH)_(2)gtBe(OH)_(2)`
`i.e., Be(OH)_(2)` has the lowest value of `K_(sp)`.