Semmelweis Chemistry Entrance Practice Exam 2026 – The All-in-One Guide to Mastering Your Admission!

In a chemical reaction, the relationship between pressure and the number of moles of gas is determined by Le Chatelier's Principle. This principle states that if an external change is applied to a system at equilibrium, the system will adjust to counteract that change and restore a new equilibrium state.

When it comes to pressure, increasing the pressure of a gaseous system will shift the equilibrium position towards the side of the reaction with fewer moles of gas. This is because reducing the number of gas moles at equilibrium decreases the pressure, which counters the initial increase.

Therefore, when the problem indicates that increasing pressure favors the products, it directly suggests that the products side of the reaction has fewer moles of gas compared to the reactants. This shift occurs to minimize the change in pressure. As a result, the correct answer is that the products have fewer moles of gas.