question_answer

What is the value of x in the potash alum \[{{K}_{2}}S{{O}_{4}}.A{{l}_{x}}{{(S{{O}_{4}})}_{3}}.24{{H}_{2}}O\]?

A)  4               

B)  1

C)  2               

D)  None of these

Correct Answer: C

Solution :

 Potash alum is a double salt. Potash alum : \[{{K}_{2}}S{{O}_{4}}.A{{l}_{x}}{{(S{{O}_{4}})}_{3}}.24{{H}_{2}}O\]

Ion
Valency

Hence, the compound of\[A{{l}^{3+}}\]and\[SO_{4}^{2-}\]is\[A{{l}_{2}}{{(S{{O}_{4}})}_{3}}\]. On comparison\[x=2\].