This question is about the reacting particle model and the rate of reaction.
Complete the sentences.
Use words from the list: activation energy, collide, energy, product, repel, temperature
For a reaction to happen, reactant particles must ...... with each other. The collision must have enough ...... . The minimum energy that particles need to react is called the ...... .
The table shows some changes to reactions.
| Change | Effect on the rate of reaction |
|---|---|
| using a higher temperature | ? |
| using more dilute acid | ? |
| using larger lumps of a solid (same mass) | ? |
| increasing the pressure of reacting gases | ? |
Complete the table. Write increases or decreases in each row.
Magnesium reacts faster with concentrated hydrochloric acid than with dilute hydrochloric acid.
Explain why. Use ideas about particles.
Milk goes sour because of chemical reactions. Milk goes sour more slowly in a fridge than on a kitchen table.
Explain why. Use ideas about particles and energy.
56 exam-style questions on OCR GCSE Chemistry 5.2 Controlling reactions, covering 5.2.1 Measuring and interpreting rate of reaction, 5.2.2 Factors affecting rate and collision theory, and 5.2.3 Catalysts, activation energy and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.