Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
Elements, Compounds and Mixtures
69 practice questions
Topics covered
Practice questions
1–10 of 30 · Normal
Question 1
2 marks · Normal
Answer and see the solution →State whether each of the following substances is an element, a compound, or a mixture. (a) Silver (b) Seawater
Question 2
4 marks · Normal
Answer and see the solution →(a)[2 marks]Explain how you could use melting point to distinguish between pure salt and a mixture of salt and sand. (2 marks)
(b)[2 marks]Predict how the boiling point of a mixture of water and alcohol compares to the pure substances, and explain your answer. (2 marks)
Question 3
3 marks · Normal
Answer and see the solution →A sample contains 8 g of oxygen and 2 g of hydrogen. Describe whether this sample is a compound or a mixture, and state the formula of the compound (if any) that could be formed by these elements. Show your calculation.
Question 4
3 marks · Normal
Answer and see the solution →Paracetamol is a pure compound. Explain, using ideas about melting and boiling points, how you could prove that a sample of paracetamol is not a mixture. (3 marks)
Question 5
4 marks · Normal
Answer and see the solution →Sample table showing types of substances found in air. Substance Type Oxygen Water vapour Carbon dioxide Helium Dust particles (a)[3 marks]Complete the table by identifying each substance as an element, a compound, or a mixture. (3 marks)
(b)[1 mark]Is air itself an element, a compound, or a mixture? Explain your answer. (1 mark)
Question 6
1 mark · Normal
Answer and check →Which statement describes a key difference between a pure substance and a mixture?
- A.A pure substance has a sharp melting point; a mixture melts over a range.
- B.A pure substance can be separated by physical means only.
- C.A mixture contains only one type of atom.
- D.A pure substance always contains two different elements.
Question 7
2 marks · Normal
Answer and see the solution →State whether each of the following is an element, a compound, or a mixture: (a) Hydrogen chloride gas (b) Brass
Question 8
4 marks · Normal
Answer and see the solution →(a)[2 marks]Describe the melting point behaviour of a pure solid and a mixture during heating. (2 marks)
(b)[2 marks]A student finds that her sample of a white solid melts over the range 150°C to 163°C. What does this suggest about the purity of the sample? (2 marks)
Question 9
2 marks · Normal
Answer and see the solution →State one separation technique that could be used to obtain pure water from salty water, and one technique that could be used to obtain pure salt from salty water.
Question 10
4 marks · Normal
Answer and see the solution →(a)[2 marks]Describe the steps needed to obtain pure crystals of copper sulfate from a mixture of copper sulfate and sand.
(b)[2 marks]Explain why filtration is a necessary step in this process.