Question

What is the effect of increasing pressure on the equilibrium position for the following reaction: 2SO2(g) + O2(g) ⇌ 2SO3(g) Assuming the reaction is at equilibrium, how would the concentrations of SO2, O2, and SO3 be affected by increasing the pressure of the system?

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, increasing the pressure will cause the reaction to shift in the direction that reduces the number of moles of gas, thus reducing the pressure.For the given reaction:2SO2 g  + O2 g   2SO3 g There are 3 moles of gas on the reactant side  2 moles of SO2 and 1 mole of O2  and 2 moles of gas on the product side  2 moles of SO3 . When the pressure is increased, the equilibrium will shift to the side with fewer moles of gas, which is the product side  formation of SO3 .As a result, the concentrations of SO2 and O2 will decrease, and the concentration of SO3 will increase. This is because the reaction will proceed in the forward direction to produce more SO3, consuming SO2 and O2 in the process.