Question

Alum is found to contain hydrated monovalent cation ${\left[M{\left(H_{2}O\right)}_6\right]}^{+}$, trivalent cation ${\left[M{\left(H_{2}O\right)}_6\right]}^{3+}$ and ${SO}_4^{2-}$ in the ratio of:

• A. 1 : 1 : 1
• B. 1 : 2 : 3
• C. 1 : 3 : 2
• D. 1 : 1 : 2

Answer 1

The correct option is D 1 : 1 : 2

Solution:- (D) $1:1:2$

The formula of alum is $K_{2}S{O}_4.{Al}_2{\left(S{O}_4\right)}_3.24H_{2}O$.

There are $2$ monovalent cation, $2$ trivalent cations and $4{S{O}_4}^{-2}$ ion.

Thus the ratio of hydrated monovalent cation, trivalent ion and ${S{O}_4}^{-2}$ ion is $1:1:2$.