Chemistry 102: Equilibrium: Find Kc constant

Question

What is the value of the equilibrium constant K_c for the following reaction at the temperature of the mixture?

NO2​(g)N2​O4​(g)

Analyses of an equilibrium mixture of N₂O₄(g) and NO₂(g) gave the following results:

[NO₂(g)] = 4.829×10^-3 M

[N₂O₄(g)] = 3.016×10^-3 M

 

Answer 1

2NO₂(g) <==> N₂O₄(g) ... balanced equation

Kc = [N₂O₄] / [NO₂]²

Kc = (3.016x10^-3) / (4.829x10^-3)²

Kc = 129.3