Question

Value of $x$ in potash alum, $K_2SO_4\cdot Al_x(SO_4)_3\cdot 24H_2O$ is

• A. $4$
• B. $1$
• C. $2$
• D. none of these

Answer 1

Answer: (C)

$2$

Answer 2

Potash alum $K_{2}SO_{4}. Al_{x}(SO_{4})_{3}.24H_{2}O$ It is a double salt Therefore, $Al_{2}(SO_{4})_{3}$- compound of $Al^{3+}$ and $SO^{2-}_{4}$ On comparing, $x=2$ Hence, formula o f potash alum is $K_{2}SO_{4}. Al_{2}(SO_{4})_{3}. 24H_{2}O$