Explain why increasing the temperature of a reaction mixture increases the rate of reaction.

AQA GCSE Chemistry (8462) — 4.6.1 Rate of reaction · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (4 marks)

Increasing the temperature gives the reacting particles more kinetic energy.

This raises the frequency of collisions between the particles.

With more kinetic energy a larger proportion of the collisions have energy equal to or greater than the activation energy.

Consequently, more collisions are successful per unit time, so the rate of reaction increases.

Examiner tips

Use the term "activation energy" and "successful collisions". Explain the chain: temperature → kinetic energy → collision frequency → energy distribution → rate. Keep the answer concise and use the exact wording from the mark scheme.

Common mistakes

Failing to mention activation energy or successful collisions. Using vague phrases like "more energy" without linking to collision frequency. Writing a long paragraph instead of clear, separate points.

Mark scheme (4 marks)

Particles have more kinetic energy (at higher temperature)
Particles collide more often / frequency of collisions increases
A greater proportion of particles have energy equal to or greater than the activation energy
Therefore there are more successful collisions (per unit time), so the rate of reaction increases

Key terms in this question

rate of reaction