+1 vote
in Class 12 by kratos

Which of the following is an alum ?

(a) FeSO4 .(NH4)2SO4.6H2O

(b) NaAlO2

(c) Na2SO4 . Al2( SO4)3 . 24H2O

(d) KCl . MgCl2 . 6H2O

1 Answer

+4 votes
by kratos
 
Best answer

Correct option (c) Na2SO4 . Al2( SO4)3 . 24H2O

Explanation:

The term alum is used for all the double sulphates having the composition,M2SO4. M'2( SO4)3.24H2O Where M stands for monovalent basic **** such Na+, K+ , etc. and M' for trivalent basic **** such as Al3+,. Cr3+, etc.

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