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 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 exams 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
Beth uses chromatography to work out which amino acids are present in an unknown sample.
The amino acids are colourless and soluble in water.
She also has pure samples of three amino acids which may be in the unknown sample.
a) Describe how Beth should set up the chromatogram. You may use a diagram in your answer. [5 marks]
b) State what other substance Beth will need in order to reveal the result. [1 mark]
The solvent travels 4 cm up the chromatogram. The unknown sample produces two spots with Rf values of 0.5 and 0.75.
The results below show how far each pure sample of amino acid travelled.
| Amino acid | Distance travelled |
| 1 | 2 cm |
| 2 | 1 cm |
| 3 | 3 cm |
| Amino acid | 1 |
|---|---|
| Distance travelled | 2 cm |
| Amino acid | 2 |
|---|---|
| Distance travelled | 1 cm |
| Amino acid | 3 |
|---|---|
| Distance travelled | 3 cm |
c) Write down the two amino acids in the unknown sample. [2 marks]
Beth then wants to investigate the coloured pigments found in a plant leaf. The pigments are not soluble in water.
d) Describe two ways in which Beth will need to change her experiment. [2 marks]
a) The following are valid points that could be included in your answer:
- draw start line with pencil [1]
- put a dot of each pure amino acid [1] and the unknown sample on the line [1]
- add water/solvent [1]
- make sure the solvent is below the level of the dots [1]
b) Locating agent [1]
c) Amino acid 1 and 3 [2]
d) The following are valid points that could be included in your answer:
- Beth will no longer need a locating agent as the pigments are coloured [1]
- she will need to use a non-aqueous solvent/use a different solvent to water [1]
