Which of the following equilibria would be impacted by a change in pressure? Select the correct answer below:

H2 (g) + I2 (g) →2HI (g)

NO (g) + O3 (g) →NO2 (g) + O2 (g)

2SO3 (g) →2SO2 (g) + O2 (g)

CO (g) + H2O (g) →CO2 (g) + H2

Based on Le Chatelier's principle the following factors affect the equilibrium of a chemical reaction:

1) Temperature

2) pressure

3) change in concentration

4) catalyst

In the given examples, the reactants and products are in the gas phase. In a, b and d the number of moles of reactants is equal to the number of moles of the products. However, in (c) number of moles of products is greater than the reactants. Hence, its equilibria will be affected the most by a change in pressure.

Ans (c)

2SO3 (g) → 2SO2 (g) + O2 (g)