Assessment and Qualifications Alliance (AQA) GCSE Chemistry Paper 2 Practice Exam 2026 - Free GCSE Chemistry Practice Questions and Study Guide

In an endothermic reaction, heat is absorbed from the surroundings, meaning that the forward reaction (which produces products) requires energy. According to Le Chatelier's Principle, if the temperature of an endothermic reaction is decreased, the system will respond by favoring the reaction that produces heat to counteract the change.

This means that the equilibrium will shift towards the reactants because the forward reaction is endothermic and relies on heat to proceed. As a result, the amount of products at equilibrium will decrease since the reaction is less favorable without additional heat.

By lowering the temperature, the system attempts to restore balance, leading to a position where fewer products are formed.