GCSE Chemistry revision

The effect of temperature changes on equilibrium

Reversible reactions and dynamic equilibrium

AQA 4.6.2.6 Higher Tier only

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Decreasing the temperature causes the equilibrium to shift in the exothermic direction (to the right in the Haber process) to release heat and counteract the change.
Increasing the temperature causes the equilibrium to shift in the endothermic direction (to the left in the Haber process), producing more reactants and less ammonia.

1. Effect of Temperature on Equilibrium AQA

Decreasing the temperature causes the equilibrium to shift in the exothermic direction (to the right in the Haber process) to release heat and counteract the change.
Increasing the temperature causes the equilibrium to shift in the endothermic direction (to the left in the Haber process), producing more reactants and less ammonia.

In a reversible reaction, the products formed can react together to reform the original starting reactants, indicated in a chemical equation by the two-way double arrow symbol (⇌).
Example: Heating blue hydrated copper(II) sulfate drives off water to form white anhydrous copper(II) sulfate; adding water back to the anhydrous powder reverses the reaction: hydrated copper(II) sulfate ⇌ anhydrous copper(II) sulfate + water

2. Concept of Reversibility AQA

In a reversible reaction, the products formed can react together to reform the original starting reactants, indicated in a chemical equation by the two-way double arrow symbol (⇌).
Example: Heating blue hydrated copper(II) sulfate drives off water to form white anhydrous copper(II) sulfate; adding water back to the anhydrous powder reverses the reaction: hydrated copper(II) sulfate ⇌ anhydrous copper(II) sulfate + water