Question

A 0.50 L vessel contains 1.0 mol of N2(g) and 3.0 mol of H2(g) at equilibrium at 400 K according to the following equation:N2(g) + 3H2(g) ⇌ 2NH3(g)If the volume of the vessel is suddenly decreased to 0.25 L, what will happen to the equilibrium position? Will the concentration of NH3 increase or decrease? Calculate the new equilibrium constant at this new volume.

Answer 1

When the volume of the vessel is suddenly decreased to 0.25 L, the pressure inside the vessel will increase. According to Le Chatelier's principle, the equilibrium will shift in the direction that reduces the pressure. In this case, the equilibrium will shift towards the side with fewer moles of gas, which is the right side  formation of NH3 . Therefore, the concentration of NH3 will increase.However, it is important to note that the equilibrium constant  K  is only affected by temperature, not by changes in volume or pressure. So, the equilibrium constant at the new volume will remain the same as it was at the initial volume.