Chemistry·Environmental & industrial chemistry · NSSCO 11.1
Water — properties, hardness & supply in Namibia
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Water is precious — especially in Namibia. Learn the chemical and physical tests for water, what makes water hard or soft, how to soften it and remove scale, and how Namibia's scarce water is supplied, purified and threatened by pollution.
What you'll learn in this lesson
By the end you should be able to (NSSCO Chemistry 11.1):
- Describe a chemical test for water (anhydrous copper(II) sulfate or cobalt(II) chloride)
- Describe how to test the purity of water using melting/boiling point
- Discuss the distribution and availability of water in Namibia
- Identify hard water as containing calcium and magnesium salts; define scum
- Explain temporary hardness (hydrogencarbonate) and permanent hardness (sulfate) and how to soften each
- Describe scale formation and its removal with dilute acid
- Describe the need for NPK fertilisers and the danger of eutrophication
- Describe purification of the water supply (filtration and chlorination) and water scarcity in Namibia
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