The equilibrium constant for the chemical equation
2NO(g) + O₂(g) ⇌ 2NO₂(g)
is two times the equilibrium constant for the chemical equation
NO(g) + ¹/₂O₂(g) ⇌ NO₂(g).

Question

The equilibrium constant for the chemical equation 2NO(g) + O₂(g) ⇌ 2NO₂(g) is two times the equilibrium constant for the chemical equation NO(g) + ¹/₂O₂(g) ⇌ NO₂(g).

Quizplus · Accepted Answer

The equilibrium constant (K) for a reaction is determined by the stoichiometry of the reaction as written. Doubling the coefficients in a chemical equation squares the equilibrium constant, not doubles it. Therefore, if the second equation represents the first equation with all coefficients halved, its equilibrium constant would be the square root of the first, not half.

The Equilibrium Constant for the Chemical Equation