Question

Consider the following reaction and its equilibrium constant at some temperature.2NH3(g) = N₂(g) + 3H₂(g) K₂=35If the following concentrations are present initially:[NH3] = 0.10 M; [N₂] = 2.00 M; [H₂) = 2.00 M..Which of the following is correct about the reaction?1.The reaction is at equilibrium.2.The reaction is not at equilibrium, it will shift to the left to reach equilibrium.3.the reaction is not at equilibrium it will shift to the right to reach equilibrium.

Answer 1

The equilibrium constant is given by the following expression.

$K=\frac{[N_2][H_2]^3}{[NH_3]^2}$

Where K is the constant and [N2], [H2] and [NH3] are the concentrations of each substance.

Replace for the given values and see if the equation is true:

$\begin{gathered} 35=\frac{2.00\cdot2.00^3}{0.10^2} \\ 35=\frac{2.00\cdot8.00}{0.01} \\ 35=\frac{16.00}{0.01} \\ 35\ne1600 \end{gathered}$

It means that the reaction is not at equilibrium.

At this point, since the result is greater than the given constant, it is necessary to increase the amount of reactants and decrease the amount of products to reach the equilibrium.

It means that the reaction has to shift to the left to reach the equilibrium.

The correct answer is choice number 2.