A student writes that tap water in the UK is pure water. Which statement explains why the student is wrong?
Tap water has been sterilised, and sterilised water is never pure
Tap water boils at 100 ∘C100\ ^\circ\text{C}100 ∘C, but pure water boils below this value
Tap water contains dissolved substances, so it is not a single substance
Tap water has passed through filter beds, so it contains solid particles
40 exam-style questions on AQA GCSE Chemistry 10.1 Using the Earth's resources and obtaining potable water, covering 10.1.1 Using the Earth's resources and sustainable development, 10.1.2 Potable water, 10.1.3 Waste water treatment, and 10.1.4 Alternative methods of extracting metals. Each one has a worked solution and a mark scheme showing where the marks go.