Q. Equimolar solutions of the following were prepared in water separately. Which one of the solutions will record the highest pH?
A) CaCl₂
B) SrCl₂
C) BaCl₂
D) MgCl₂
Explanation
[Solution from source] Small, highly polarising cations such as Mg²⁺ hydrolyse water slightly and make the solution acidic. This tendency falls down the group as the cation grows, and Ba²⁺ hardly hydrolyses, so BaCl₂ is nearly neutral and has the highest pH. MgCl₂ gives the lowest pH. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.