Year 11 - Science
Concentration and rate: practical using end point method
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 carry out a fair test to investigate how the rate of reaction depends on the concentration of a reacting solution.
Key Notes
- The reaction between sodium thiosulfate solution and hydrochloric acid produces a cloudy precipitate.
- At the end point of the disappearing cross experiment, each reaction has produced the same amount of product.
- At the end point of the disappearing cross experiment, the chemical reaction may not be complete.
- Increasing concentration of a reacting solution introduces more reactant particles, so they collide more frequently.
Vocabulary To Learn
- rate of reaction: Rate of reaction is the speed with which a chemical reaction takes place.
- end point method: An end point method is used to measure the progress of a reaction until it has reached completion or a desired point e.g. a colour change.
- precipitate: A precipitate is an insoluble solid formed when two solutions react together.
- fair test: In a fair test variables are controlled so that only one change affects the dependent variable.
Common Mistakes To Avoid
- The reaction stops when the 'X' is no longer visible.
3 Quick Questions (With Answers)
1. Explain the scientific idea in this lesson using two key points.
The reaction between sodium thiosulfate solution and hydrochloric acid produces a cloudy precipitate. At the end point of the disappearing cross experiment, each reaction has produced the same amount of product.
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: The reaction stops when the 'X' is no longer visible. Correction: The disappearance of the cross only indicates that the sulfur precipitate has formed sufficiently to obscure the cross. The reaction itself continues beyond this point until all reactants are consumed.
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 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
- The rate of a chemical reaction: including graphs Study Guide
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