Practical questions
You will complete eight Practical Activity Groups (PAGs) if you are studying GCSE Chemistry. If you are studying GCSE Combined Science you will complete 16, of which five are in Chemistry.
You could be asked questions about the apparatus, methods, safety precautions, results, analysis and evaluation of these experiments.
There are no PAGs in the Organic chemistry section.
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Dr Alex Lathbridge answers questions about practicals.
Sample question 1 - Foundation
Question
Hexane and hexene are hydrocarbons. They are flammable liquids and have irritating vapours. A student adds a few drops of bromine water to a small volume of hexane in a test tube, then shakes the mixture. She repeats this test using hexene.
a) Explain how the results of the student鈥檚 tests distinguish between hexane and hexene. [2 marks]
b) Give one suitable safety precaution, and explain your answer. [2 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
The following are vaild points that could be included in your answer. It is important that you do not bullet point your answer but write your sentences in full.
a)
- hexane - no change seen/mixture stays orange/brown [1]
- hexene - bromine water is decolourised/mixture changes from orange/brown to colourless [1]
No marks if answer is 'clear' rather than 'colourless'.
b) One mark for precaution, one mark for matching reason, eg:
- avoid naked flames because hydrocarbons are flammable
- wear gloves to avoid skin contact from hexane/hexene/bromine water
- work in a fume cupboard because hexane/hexene has irritating vapour
[2]