This deep dive covers The Four Factors That Affect Rate within Factors Affecting Rate for GCSE Chemistry. Revise Factors Affecting Rate in Rates of Reaction for GCSE Chemistry with 24 exam-style questions and 18 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 2 of 13 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
🔬 The Four Factors That Affect Rate
🌡️ 1. TEMPERATURE — Higher = Faster
- Particles have more kinetic energy
- Particles move faster → more frequent collisions
- More particles have energy ≥ activation energy
- Both effects increase successful collisions
🧪 2. CONCENTRATION — Higher = Faster
- More particles in the same volume
- Particles are closer together
- More frequent collisions
- More successful collisions per second
For gases: increasing PRESSURE has the same effect.
🔨 3. SURFACE AREA — Larger = Faster
- More particles are exposed to the other reactant
- More collisions can happen at once
- Powders react faster than lumps
Same mass, but powder has much more exposed surface.
⚡ 4. CATALYSTS — Speed up without being used up
- Provides an alternative reaction pathway
- With a lower activation energy
- More particles now have enough energy to react
- Catalyst is unchanged at the end — can be reused
Practice questions for Factors Affecting Rate
Which of the following factors does NOT affect the rate of a chemical reaction?
Explain, in terms of particles, why increasing temperature increases the rate of reaction.