Knowledge Organiser: Collision Theory & Rate of Reaction
Part of Rates & Collision Theory · GCSE GCSE Chemistry revision
This topic summary covers Knowledge Organiser: Collision Theory & Rate of Reaction within Rates & Collision Theory for GCSE Chemistry. Revise Rates & Collision Theory in Rates of Reaction for GCSE Chemistry with 20 exam-style questions and 16 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 14 of 14 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 14 of 14
Practice
20 questions
Recall
16 flashcards
Knowledge Organiser: Collision Theory & Rate of Reaction
Key Terms
- Rate of reaction — amount ÷ time
- Activation energy (Ea) — minimum energy for reaction
- Successful collision — energy ≥ Ea + correct orientation
- Collision theory — particles must collide with correct energy and orientation
Must-Know Facts
- Rate formula: amount ÷ time (units: g/s, cm³/s)
- Steeper graph = faster rate
- Horizontal line = reaction finished
- Same final height = same amount of product
- CEO rule: Collide + Energy + Orientation
Measuring Rate Methods
- Gas syringe — volume of gas over time
- Mass balance — mass loss over time
- Disappearing cross — turbidity timing
- Colorimeter — colour intensity change
Common Exam Errors
- Forgetting "successful collisions" in explanations
- Confusing rate with total product amount
- Missing units in rate calculations
- Not explaining WHY orientation matters
Key Equations
- Rate = amount of product formed ÷ time (or amount of reactant used ÷ time)
- Rate units: g/s, cm³/s, or mol/s
- Mean rate = gradient of tangent on concentration-time graph
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Practice Questions for Rates & Collision Theory
According to collision theory, which of the following must happen for a chemical reaction to take place?
Explain, using collision theory, why increasing the concentration of a reactant solution increases the rate of reaction.
Quick Recall Flashcards
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