0 votes
45 views
in Chemical equilibrium by (450 points)
A student wants to know how changing the volume affects the position of the equilibrium for the reaction N2(g) + 3H2(g) ⇌ 2NH3(g). If the reaction is initially at equilibrium in a 2 L container at 400 K and then the volume is decreased to 1 L, what will be the new concentrations of each gas at equilibrium? (Assume that the pressure remains constant and that the reaction follows

1 Answer

0 votes
by (530 points)
To solve this problem, we need to use the reaction quotient  Q  and the equilibrium constant  K  for the reaction. The reaction quotient is given by the formula:Q = [NH3]^2 /  [N2] * [H2]^3 At equilibrium, Q = K. Let's assume that the initial concentrations of N2, H2, and NH3 are [N2]0, [H2]0, and [NH3]0, respectively. We are not given the initial concentrations, but we can express them in terms of moles  n  and volume  V :[N2]0 = n_N2 / 2 L[H2]0 = n_H2 / 2 L[NH3]0 = n_NH3 / 2 LWhen the volume is decreased to 1 L, the concentrations will change:[N2]1 = n_N2 / 1 L[H2]1 = n_H2 / 1 L[NH3]1 = n_NH3 / 1 LSince the pressure remains constant, the number of moles of each gas will not change. Now, let's consider how the change in volume affects the reaction quotient:Q =  [NH3]1 ^2 /  [N2]1 * [H2]1^3 Since Q must equal K at equilibrium, we can set up the following equation: [NH3]0 ^2 /  [N2]0 * [H2]0^3  =  [NH3]1 ^2 /  [N2]1 * [H2]1^3 Now, we can substitute the expressions for the concentrations in terms of moles and volume: n_NH3 / 2 L ^2 /  n_N2 / 2 L *  n_H2 / 2 L ^3  =  n_NH3 / 1 L ^2 /  n_N2 / 1 L *  n_H2 / 1 L ^3 Simplifying the equation, we get: n_NH3 ^2 /  n_N2 *  n_H2 ^3  = 8 *  n_NH3 ^2 /  n_N2 *  n_H2 ^3 Since the equilibrium constant K does not change, the reaction will shift to maintain the same value of K. In this case, the reaction will shift towards the side with fewer moles of gas to counteract the decrease in volume. The reaction will shift towards the formation of NH3, which means that the concentrations of N2 and H2 will decrease, and the concentration of NH3 will increase.However, without the initial concentrations or the value of K, we cannot determine the exact new concentrations of each gas at equilibrium.

Related questions

Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...