Question

Alum is a double sulphate.

(a) true

(b) false

I got this question in an online interview.

I need to ask this question from p-Block Elements topic in portion p-Block Elements of Chemistry – Class 11

Answer 1

Correct choice is (a) true

To elaborate: The term alum is given to double sulphates of the type X2SO4.Y2(SO4)3.24H2O where, X represents a monovalent cation such as sodium ion, potassium ion and ammonium while why is a trivalent cation such as aluminium 3 +, chromium 3 +, ferrous 3 + and Cobalt 3 +. Lithium-ion does not form alum.