A water treatment works makes potable water from ground water. The water passes through filter beds and then chlorine is added.
Explain why filtration removes solid particles from the water but does not remove dissolved salts.
Explain why chlorine is added to the water.
Chlorine is added at a dose of 0.50 mg per dm3\mathrm{dm^{3}}dm3 of water. The works treats 2.0 × 106 dm3\mathrm{dm^{3}}dm3 of water each day. Calculate the mass of chlorine, in kg, used each day.
In some dry countries, sea water is made potable by distillation. Explain how distillation makes sea water potable.
Suggest why most drinking water in the UK is not made by distilling sea water.
48 exam-style questions on Edexcel GCSE Chemistry 3.2 Methods of separating and purifying substances, covering 3.2.1 Pure substances and mixtures, 3.2.2 Techniques for separating mixtures, 3.2.3 Paper chromatography and Rf values, and 3.2.4 Making water potable. Each one has a worked solution and a mark scheme showing where the marks go.