We are being asked to calculate the equilibrium constant, Kc for the given equilibrium reaction:
2 NH3(g) ⇌ N2(g) + 3 H2(g)
When dealing with equilibrium and Kc:
• Kc → equilibrium units are in molarity
• Kc is an equilibrium expression:
▪ only aqueous and gaseous species are included in the equilibrium expression
▪ the coefficient of each compound in the reaction equation will be the exponent of the concentrations in the equilibrium expression
When 0.60 mol NH 3 is decomposed in a 1 Liter flask at 850 K, the equilibrium concentration of NH3 is measured as 0.12 M. Given that ammonia decomposes according to the reaction 2 NH3(g) ⇌ N2(g) + 3 H2(g), what is Kc for the reaction?