Sample exam questions - chemical changes - AQAStructured questions and short answer questions

Understanding how to approach exam questions helps to boost exam performance. Question types will include multiple choice, structured, mathematical and practical questions.

Part ofCombined ScienceChemical changes

Structured questions and short answer questions

Questions with 1, 2, 3 or 4 marks usually start with command words. If a question starts with the command word 'state', 'give', 'name' or 'write down', it needs a short answer only. This type of question can often be answered with one word or phrase.

It is important to state, give, name or write down the number of things that the question asks for. If you write down fewer, you cannot get all the marks. If you write down more, and one is wrong, you might lose a mark.

Learn about command words with Dr Alex Lathbridge

Understanding the different command words in your science GCSE exams.

Some questions start with the command words 'describe', 'explain' or 'compare'. These are often worth two or more marks:

  • Describe means you should recall facts, events or processes accurately. You might need to give an account of what something looked like, or what happened.
  • Explain means you need to make something clear, or state the reasons for something happening. The points in the answer must be linked together. The answer must not be a list of reasons. All the points must be relevant to the question.
  • Compare means you need to describe similarities and differences between things. If you are asked to compare X and Y, write down something about X and something about Y, and give a comparison. Do not just write about X only or Y only.

More complex structured questions will be worth three or four marks. They include questions with complex descriptions and explanations, and questions in which you need to compare things.

Some of the answers are shown here as bullet points. This is to show clearly how a mark can be obtained. However, do not use bullet points in your answers - the points must be linked together logically.

These questions have been written by Bitesize consultants as suggestions to the types of questions that may appear in an exam paper.

Sample question 1 - Foundation

Question

A student added copper oxide to sulfuric acid. The reaction made copper sulfate solution. Describe how the student could obtain dry copper sulfate crystals from the solution. [4 marks]

Sample question 2 - Foundation

Question

A student adds small pieces of magnesium and copper to separate test tubes of dilute acid. Compare the observations she would make in the two test tubes. [4 marks]

Sample question 3 - Higher

Question

Sulfuric acid is a strong acid. What is meant by a strong acid? [2 marks]

Sample question 4 - Higher

Question

Aluminium is extracted from aluminium oxide by electrolysis.

In the electrolysis cell, there is a mixture of aluminium oxide and molten cryolite. Explain why. [3 marks]