This how it works covers How Le Chatelier's Principle Works within Equilibrium (HT) for GCSE Chemistry. Revise Equilibrium (HT) in Rates of Reaction for GCSE Chemistry with 23 exam-style questions and 18 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 5 of 14 in this topic. Use this how it works to connect the idea to the wider topic before moving on to questions and flashcards.
⚙️ How Le Chatelier's Principle Works
Le Chatelier's Principle is not magic — it has a chemical explanation. When conditions change, the forward and backward reaction rates become temporarily unequal, causing a net shift until equilibrium is re-established.
Example — adding more reactant:
- Adding reactant increases its concentration
- This increases the forward reaction rate (more collisions)
- The backward rate is momentarily unchanged
- Products accumulate → backward rate increases
- A new equilibrium is reached with more products — the position has shifted right
Example — increasing temperature (for an exothermic forward reaction):
Think of heat energy as an extra reactant. Adding more heat is like adding more of that reactant — it pushes the equilibrium toward the endothermic direction, which uses up the extra heat.
- More heat is supplied to the system
- The system opposes the change by shifting in the direction that absorbs heat — the endothermic (backward) direction
- More reactants form — equilibrium position shifts left
- The yield of products decreases (but rate of reaching equilibrium increases)
Practice questions for Equilibrium (HT)
At dynamic equilibrium, which of the following is true?
Explain the effect of increasing temperature on the position of an equilibrium where the forward reaction is exothermic.