An equilibrium mixture contains 0.400 mol nh3, 0.200 mol n2, 0.300 mol h2 in a 2.0 L container

equilibrium-constant

#1

An equilibrium mixture contains 0.400 mol nh3, 0.200 mol n2, 0.300 mol h2 in a 2.0 L container. What is the equilibrium constant for the reaction?

Answer:

First we need a chemical equation, because without it we cant tell where to place our reactants and products in the equilibrium expression(Kc). you produce the following equation:

N2(g)+3H2(g)---->2NH3(g)

The problem states that in an equilibrium mixture you already have the amount of NH3, N2 and H2 in moles(which is at equilibrium). You are given Liters, so you can convert moles to Molarity using the 2.0 Liters M=n/V. 0.400 mol NH3/2.0 L, 0.200 mol N2/2.0 L, and 0.300 mol H2/2.0 L, and respectively you get 0.20 M NH3, 0.10 M N2, and 0.15 M H2.

Kc = [NH3]^2/[N2][H2]^3 =
(0.20)^2/(0.10)(0.15)^3 =
1.2x10^2