Chemistry Year 12 - Module 5 - Lesson 3
Collision Theory Applied to Equilibrium
1. Key Ideas
When you squeeze a syringe full of brown NO₂ gas, it gets paler — not because gas escapes, but because the increased collision frequency drives the equilibrium toward the colourless N₂O₄, and watching that colour change in real time is watching collision theory in action.
- How collision theory explains the approach to equilibrium
- Why decreasing temperature shifts an exothermic reaction to the right using E a reasoning
2. Success Criteria
By the end, you should be able to:
- How collision theory explains the approach to equilibrium
- The relationship ΔH = Eₐ(forward) − Eₐ(reverse)
- Why a catalyst does not shift equilibrium position or change K eq
3. Key Terms
4. Activity: Build the Lesson Map
Use the lesson to complete the table. Keep answers brief but specific.
| Prompt | Your answer |
|---|---|
| Main concept | |
| Important example | |
| Common mistake to avoid | |
| How this links to the next lesson |
5. Short Answer Questions
1. Explain this lesson goal in your own words: "How collision theory explains the approach to equilibrium". Use one specific example from the lesson.
2. Apply this idea to a new example: "The relationship ΔH = Eₐ(forward) − Eₐ(reverse)". Show your reasoning clearly.
3. Analyse why this idea matters for understanding Collision Theory Applied to Equilibrium: "Why a catalyst does not shift equilibrium position or change K eq".
6. Extend: Apply the Idea
A student gives a memorised answer about Collision Theory Applied to Equilibrium but does not use evidence or reasoning.
Improve the answer by writing a stronger response that uses accurate terminology, a relevant example and a clear explanation.
7. Multiple Choice
1. What is the best first step when answering a question about Collision Theory Applied to Equilibrium?
A. Identify the key concept being tested
B. Write every fact from memory
C. Ignore the command word
D. Skip examples and evidence
2. Which answer would show stronger understanding of Collision Theory Applied to Equilibrium?
A. An answer with accurate terms and reasoning
B. A copied definition only
C. A single-word response
D. An answer with no example
3. What should you do if a question asks you to explain?
A. Link the idea to a reason or cause
B. List unrelated facts
C. Only draw a diagram
D. Write the shortest possible answer
8. Success Criteria Proof
Finish with evidence that you can do each success criterion.