Q. For the reaction N₂(g) + O₂(g) ⇌ 2NO(g), the equilibrium constant is K₁. The equilibrium constant is K₂ for the reaction 2NO(g) + O₂(g) ⇌ 2NO₂(g). What is K for the reaction NO₂(g) ⇌ (1/2)N₂(g) + O₂(g)?
A) 1/(K₁K₂)
B) 1/(2K₁K₂)
C) 1/(4K₁K₂)
D) [1/(K₁K₂)]^(1/2)
Explanation
[Solution from source] Adding the two given reactions gives N₂ + 2O₂ ⇌ 2NO₂ with K = K₁K₂. The required reaction is the reverse of this halved, so K = (K₁K₂)^(−1/2) = [1/(K₁K₂)]^(1/2). Halving a reaction takes the square root of K; it does not divide K by 2. Answer (4).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.