During the purification of municipal drinking water, the water is passed through a bed of activated carbon (charcoal). What is the primary function of this step in the purification process?
To precipitate dissolved heavy metal ions as insoluble hydroxides.
To adsorb dissolved trace organic molecules, volatile compounds, and unpleasant odours.
To coagulate microscopic suspended clay and silt particles into larger settleable flocs.
To sanitise the water by oxidising and destroying remaining pathogenic micro-organisms.
107 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.