Q. In potash alum, the ratio of K⁺ and SO₄²⁻ ions is
A) 3 : 2
B) 1 : 2
C) 2 : 1
D) 2 : 3
Explanation
[Solution from source] Potash alum is KAl(SO₄)₂·12H₂O; as a double salt it dissociates completely into K⁺, Al³⁺ and SO₄²⁻. Per formula unit there is one K⁺ for two SO₄²⁻, a 1 : 2 ratio. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.