When [H2] =0.1 M, [N2] = 0.1M and [NH3] = 0.1M. What is the equilibrium constant for this reaction? 2 NH3(g) <=> 3 H2(g) + N2(g)
The Correct Answer and Explanation is:
To find the equilibrium constant KcK_cKc for the reaction:2 NH3(g)⇌3 H2(g)+ N2(g)2 \, \text{NH}_3(g) \rightleftharpoons 3 \, \text{H}_2(g) + \, \text{N}_2(g)2NH3(g)⇌3H2(g)+N2(g)
We use the expression for the equilibrium constant in terms of concentrations:Kc=[H2]3×[N2][NH3]2K_c = \frac{[\text{H}_2]^3 \times [\text{N}_2]}{[\text{NH}_3]^2}Kc=[NH3]2[H2]3×[N2]
Given concentrations at equilibrium:
- [H2]=0.1 M[H_2] = 0.1 \, \text{M}[H2]=0.1M
- [N2]=0.1 M[N_2] = 0.1 \, \text{M}[N2]=0.1M
- [NH3]=0.1 M[NH_3] = 0.1 \, \text{M}[NH3]=0.1M
Now, substitute the values into the equation:Kc=(0.1)3×(0.1)(0.1)2K_c = \frac{(0.1)^3 \times (0.1)}{(0.1)^2}Kc=(0.1)2(0.1)3×(0.1)
Simplify the calculation:Kc=(0.001)×(0.1)0.01K_c = \frac{(0.001) \times (0.1)}{0.01}Kc=0.01(0.001)×(0.1)Kc=0.00010.01=0.01K_c = \frac{0.0001}{0.01} = 0.01Kc=0.010.0001=0.01
So, the equilibrium constant KcK_cKc for this reaction is 0.01.
Explanation:
The equilibrium constant is a measure of the ratio of the concentrations of products to reactants at equilibrium. If the concentrations of reactants and products are given, the equilibrium constant can be calculated by plugging them into the appropriate equation. In this case, the reaction involves the formation of ammonia from hydrogen and nitrogen, and the equilibrium constant reflects how far the reaction has proceeded toward products or reactants at equilibrium.
If KcK_cKc is much greater than 1, it indicates that the equilibrium favors products. If KcK_cKc is much less than 1, it indicates that the equilibrium favors reactants. Since Kc=0.01K_c = 0.01Kc=0.01, this means the equilibrium lies more toward the reactants (NH3) than the products (H2 and N2).
