This free course, What chemical compounds might be present in drinking water?, examines the chemical compounds that occur in drinking water. A high level of certain anions in water can cause environmental pollution and health problems. Cations are also important. For example, calcium salts contribute to the hardness of water and water treatment uses aluminium compounds. Additionally oxidising agents, such as ozone or chlorine, are vital in the disinfection of water. This OpenLearn course focuses on the chemistry of the p-block elements in Groups 13 to 18 of the Periodic Table.

Course learning outcomes

After studying this course, you should be able to:

• Understand that in drinking water anions have a beneficial range of concentration above which they may have an adverse effect on either human health or the environment. Toxic elements and compounds often block essential biological processes
• Explain how excess anions or cations in aqueous solution can be removed by ion-exchange chromatography or an ion-exchange membrane
• Explain how cations such as aluminium can be amphoteric, that is they can neutralise both acidic and alkaline solutions. Also recognise how this enables aluminium(III) ions to be used in water treatment