4-mark practice questions — WJEC GCSE Chemistry (Wales)
60 questions · chemistry · View as Markdown
How to answer
4-mark questions are the shortest levels-of-response band. Aim for four scientific ideas, each in its own short sentence.
Sample questions
- A food scientist is checking the purity of a sample of vanilla flavouring before it is used in a product. She carries ou…
- When water boils, it undergoes a physical change rather than a chemical change. Explain the difference between a physica…
- Describe what happens when a metal oxide reacts with a dilute acid, and explain why the product formed is called a salt.…
- Calcium hydroxide solution is used to test for carbon dioxide gas. Explain what is observed when carbon dioxide is bubbl…
- Propane (C₃H₈) is a hydrocarbon fuel used in camping gas stoves. When propane burns completely in oxygen, carbon dioxide…
- A chemist is investigating whether a sample of red food colouring is a pure substance or a mixture. She carries out pape…
- Crystallisation can be used to obtain a pure salt from a solution. Describe the steps involved in obtaining pure copper …
- A student wants to obtain a sample of pure water from a salt solution. Describe how simple distillation could be used to…