Combined ScienceCode 5129
Water
What this topic asks you to be able to do
- Describe distillation, which separates a liquid by means of evaporation followed by condensation
- Explain why, for practical work in chemistry, distilled water is preferred to tap water, since it has fewer chemical impurities
- State that water has to be treated before it is safe to drink
- Describe how the domestic water supply is treated, covering: (a) sedimentation and filtration, which remove insoluble solids (b) the use of carbon, which removes tastes and odours (c) chlorination, which kills microbes
- Describe desalination as a way of getting drinking water out of sea water