Practical questions
During the GCSE chemistry course you will complete practical activities from eight Practical Activity Groups (PAGs).
The exams will include questions about some of these experiments. You may also be asked to apply what you know to unfamiliar practical contexts, which will draw on your practical knowledge and understanding.
You could be asked to:
- write or identify a hypothesis or prediction that could be tested in an experiment
- name equipment and measuring instruments, and describe what they do and how they are used
- identify factors that must be controlled, and explain why
- describe how to work safely
- process data by doing calculations and representing them in graphs
- identify patterns and trends in data
- evaluate the accuracy, repeatability and reproducibility of data, and identify possible errors and anomalous results
- suggest improvements to methods
- interpret data and draw conclusions from it
Practical questions will appear throughout both exam papers, and at both Foundation tier and Higher tier. Practical questions could be multiple choice or free response, and could include calculations. A six-mark question could be asked in a practical context, so practice writing in detail about the practical work you have done.
It's important to look back at your lab book or your notes from the practical activities you have done when revising for your exams.
These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.
Learn about practicals with Dr Alex Lathbridge
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Dr Alex Lathbridge answers questions about practicals.
Sample question 1 - Foundation
Question
A teacher plans to demonstrate the reaction between the group 1 metal potassium, and water.
Explain why the potassium is stored in oil. [2 mark]
- potassium is highly reactive [1]
- storing it in oil prevents it from reacting with oxygen/water vapour in the air [1]
Sample question 2 - Foundation
Question
A teacher plans to demonstrate the reaction between the group 1 metals and water.
She cuts a small pea-sized piece of potassium and lithium.
Describe two differences that you would observe. [2 marks]
- the potassium is softer to cut than lithium [1]
- when cut, the shiny surface of the potassium would tarnish/disappear/be covered faster [1]
Sample question 3 - Higher
Question
Sophie carries out a series of displacement reactions.
| Potassium chloride solution | Potassium bromide solution | Potassium iodide solution | |
| Chlorine | Not done | Solution darkens | Solution darkens |
| Bromine | No visible reaction | Not done | Solution darkens |
| Iodine | No visible reaction | No visible reaction | Not done |
| Chlorine | |
|---|---|
| Potassium chloride solution | Not done |
| Potassium bromide solution | Solution darkens |
| Potassium iodide solution | Solution darkens |
| Bromine | |
|---|---|
| Potassium chloride solution | No visible reaction |
| Potassium bromide solution | Not done |
| Potassium iodide solution | Solution darkens |
| Iodine | |
|---|---|
| Potassium chloride solution | No visible reaction |
| Potassium bromide solution | No visible reaction |
| Potassium iodide solution | Not done |
Explain how these results show that chlorine is the most reactive group 7 element tested. [3 marks]
- the results show that chlorine reacts with both potassium bromide and potassium iodide [1]
- this means that chlorine is able to displace both bromine and iodine [1]
- it is therefore the most reactive [1]
Sample question 4 - Higher
Question
Steve puts a few drops of potassium bromide in a spotting tile and adds a few drops of chlorine water. He observes that the solution darkens.
a) Explain Steve's observation. [3 marks]
b) Describe and explain how Steve could extend this experiment to show order of reactivity of chlorine, bromine and iodine. [3 marks]
a)
- chlorine is more reactive than bromine [1]
- chlorine displaces bromine from solution [1]
- bromine is a brown/red colour so the solution darkens [1]
b)
- Steve should fill a row of three dips in the spotting tile with chlorine, bromine and iodine [1]
- he should add drops of potassium chloride solution, then potassium bromide solution and finally potassium iodide solution to each (but not where the same element is part of the compound) [1]
- he should complete a table of results to show where a reaction does and does not take place - the element that reacts with both other solutions is the most reactive, and the element that reacts with none is the least [1]
