Year 11 - Science
The rate of a chemical reaction: including graphs
Rate of reaction
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
This unit explores factors influencing reaction rates, including temperature, concentration, surface area, and catalysts. It covers using models and theories to develop hypotheses, planning and conducting experiments safely, selecting appropriate techniques, and presenting and translating data.
Lesson Summary
You will learn to describe what happens during a chemical reaction as it progresses over time and interpret graphs showing how the instantaneous rate of the reaction changes.
Key Notes
- Most chemical reactions start more quickly and slow down as they progress.
- The rate of a chemical reaction is equal to the amount of product formed per unit time (or reactant used per unit time).
- The mean rate of a chemical reaction is different to the instantaneous rate that changes throughout the reaction.
- Graphs of mass, volume, or concentration vs. time can all represent the changing rate of a chemical reaction.
- The gradient of a rate of reaction graph can be calculated from a tangent drawn at a point on the curve.
Vocabulary To Learn
- rate of reaction: Rate of reaction is the speed with which a chemical reaction takes place.
- mean rate of reaction: The mean rate of reaction is the average rate at which reactants are converted into products over a given period of time.
- instantaneous rate of reaction: The instantaneous rate of reaction is the rate at which reactants are converted into products at a specific moment in time.
- tangent: A tangent is a straight line that touches a curve at exactly one point without crossing it.
- gradient: The gradient on a graph represents the rate at which one quantity changes relative to another.
Common Mistakes To Avoid
- To calculate the instantaneous rate of reaction by reading values from the graph at a specific time.
3 Quick Questions (With Answers)
1. Explain the scientific idea in this lesson using two key points.
Most chemical reactions start more quickly and slow down as they progress. The rate of a chemical reaction is equal to the amount of product formed per unit time (or reactant used per unit time).
2. Define this scientific word and use it in context. 'rate of reaction'
Rate of reaction is the speed with which a chemical reaction takes place. Include the word in a full scientific explanation, not as a single label.
3. Correct this common scientific misunderstanding.
Mistake: To calculate the instantaneous rate of reaction by reading values from the graph at a specific time. Correction: Students need to draw a tangent in order to calculate the gradient of the graph at a specific time to work out the instantaneous rate of reaction.
More Lessons In This Unit
- Appropriate equipment for measuring the rate of a reaction Study Guide
- Catalysts and rate Study Guide
- Collision theory Study Guide
- Concentration and rate: analysis Study Guide
- Concentration and rate: practical using end point method Study Guide
- Concentration and rate: practical using gas collection method Study Guide
- Evaluating methods for measuring the rate of reaction Study Guide
- Surface area and rate: analysis Study Guide
- Surface area and rate: practical Study Guide
- Temperature and rate: practical Study Guide
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