Question

Consider the reaction: N2(g) + 3H2(g) ⇌ 2NH3(g)If the reaction mixture initially contains 0.10 mol N2, 0.20 mol H2 and 0.15 mol NH3 at equilibrium at 450 K, and the number of moles of NH3 is increased to 0.25 mol at constant temperature, predict the direction in which the reaction will proceed to reach a new equilibrium.

Answer 1

To predict the direction in which the reaction will proceed, we can use Le Chatelier's principle, which states that if a system at equilibrium is subjected to a change in concentration, temperature, or pressure, the system will adjust to counteract the change and restore equilibrium.In this case, the number of moles of NH3 is increased from 0.15 mol to 0.25 mol, while the moles of N2 and H2 remain constant. This change will disturb the equilibrium, and the system will respond to counteract the increase in NH3 concentration.The reaction can proceed in two directions:1. Forward direction: N2 g  + 3H2 g   2NH3 g 2. Reverse direction: 2NH3 g   N2 g  + 3H2 g Since the concentration of NH3 has increased, the system will try to decrease its concentration to restore equilibrium. This can be achieved by shifting the reaction in the reverse direction, where NH3 is consumed to produce N2 and H2.Therefore, the reaction will proceed in the reverse direction to reach a new equilibrium.