Q. In which of the following equilibria, $K_p$ and $K_c$ are NOT equal?
A) $CO_{(g)}+H_2O_{(g)}\rightleftharpoons CO_{2(g)}+H_{2(g)}$
B) $2\,BrCl_{(g)}\rightleftharpoons Br_{2(g)}+Cl_{2(g)}$
C) $PCl_{5(g)}\rightleftharpoons PCl_{3(g)}+Cl_{2(g)}$
D) $H_{2(g)}+I_{2(g)}\rightleftharpoons2\,HI_{(g)}$
Explanation
[Solution by Claude - not from source] $K_p=K_c(RT)^{\Delta n}$; $\Delta n=1$ only for $PCl_5$ decomposition. Answer (3).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.