A water company treats water from a river to make it potable.
State what is meant by potable water.
The water is treated in three stages: sedimentation, filtration and chlorination. Give the purpose of each stage.
Name the method used to make sea water potable.
Give one reason why making potable water from sea water is expensive.
Water used for chemical analysis must not contain dissolved salts. State why tap water should not be used for chemical analysis.
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.