Q. The correct order of increasing thermal stability of K₂CO₃, MgCO₃, CaCO₃ and BeCO₃ is
A) BeCO₃ < MgCO₃ < CaCO₃ < K₂CO₃
B) MgCO₃ < BeCO₃ < CaCO₃ < K₂CO₃
C) K₂CO₃ < MgCO₃ < CaCO₃ < BeCO₃
D) BeCO₃ < MgCO₃ < K₂CO₃ < CaCO₃
Explanation
[Solution from source] Thermal stability of carbonates increases as the cation becomes larger and less polarising: Be²⁺ < Mg²⁺ < Ca²⁺, and K₂CO₃ (large, singly charged K⁺) is the most stable. So BeCO₃ < MgCO₃ < CaCO₃ < K₂CO₃. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.