Question

A chemistry student needs to determine the equilibrium constant (Kc) for the reaction: N2(g) + 3H2(g) ⇌ 2NH3(g)At a certain temperature, 0.2 mole of nitrogen gas (N2), 0.3 mole of hydrogen gas (H2), and 0.4 mole of ammonia gas (NH3) were placed in a 1 L container. Using these initial concentrations, what is the equilibrium constant (Kc) for the reaction?

Answer 1

To determine the equilibrium constant  Kc  for the reaction, we first need to write the expression for Kc:Kc = [NH3]^2 /  [N2] * [H2]^3 Next, we need to find the equilibrium concentrations of each species. Since we are given the initial concentrations and the volume of the container, we can calculate the initial molar concentrations:[N2]_initial = 0.2 moles / 1 L = 0.2 M[H2]_initial = 0.3 moles / 1 L = 0.3 M[NH3]_initial = 0.4 moles / 1 L = 0.4 MNow, let's denote the change in concentration for each species as they reach equilibrium:N2: -xH2: -3xNH3: +2xAt equilibrium, the concentrations will be:[N2]_equilibrium = 0.2 - x[H2]_equilibrium = 0.3 - 3x[NH3]_equilibrium = 0.4 + 2xNow, we can substitute these equilibrium concentrations into the Kc expression:Kc = [ 0.4 + 2x ^2] /  [ 0.2 - x  *  0.3 - 3x ^3] However, we are not given enough information to determine the value of x. We would need either the equilibrium concentrations or the value of Kc at the given temperature to solve for x and then calculate Kc.