Would an increase in pressure favor the formation of ozone or of oxygen?

Answer;

An increase in pressure favors the formation of ozone

Explanation; Ozone, O3, decomposes to molecular oxygen in the stratosphere according to the reaction

2O3 (g) ⇆ 3O2 (g).

There are more moles of product gas than moles of reactant gas. An increase in total pressure increases the partial pressure of each gas, shifting the equilibrium towards the reactants. Therefore; an increase in pressure favors backward reactions towards the formation of ozone.