A chemistry student needs to determine the effect of increasing the pressure on the equilibrium position of a reaction. Consider the following reaction at equilibrium: N2(g) + 3H2(g) ⇌ 2NH3(g) If the pressure is increased, will the reaction shift to the left or right, and in what direction will the reaction quotient, Q, shift as a result? Justify your answer using Le Chatelier's principle.

Question

A chemistry student needs to determine the effect of increasing the pressure on the equilibrium position of a reaction. Consider the following reaction at equilibrium: N2(g) + 3H2(g) ⇌ 2NH3(g) If the pressure is increased, will the reaction shift to the left or right, and in what direction will the reaction quotient, Q, shift as a result? Justify your answ

Answer 1

According to Le Chatelier's principle, when a system at equilibrium is subjected to a change in pressure, the system will adjust itself to counteract the change and re-establish equilibrium. In this case, the pressure is increased.For the given reaction:N2 g  + 3H2 g   2NH3 g On the left side of the reaction, there are 1 mole of N2 and 3 moles of H2, totaling 4 moles of gas. On the right side, there are 2 moles of NH3. When the pressure is increased, the system will try to counteract the change by shifting the equilibrium position to the side with fewer moles of gas to reduce the pressure. In this case, the reaction will shift to the right, towards the formation of NH3.As the reaction shifts to the right, the concentrations of N2 and H2 will decrease, while the concentration of NH3 will increase. This will cause the reaction quotient, Q, to increase as well. The reaction will continue to shift to the right until a new equilibrium is established, where the reaction quotient Q equals the equilibrium constant K.In summary, when the pressure is increased, the reaction will shift to the right, and the reaction quotient, Q, will increase. This is in accordance with Le Chatelier's principle.