Read the article below on Swimming Pool Chemistry( start from Chlorination after the introduction ) then answer the following questions.
- The chlorination of water involves a reversible reaction in which the weak acid hypochlorous acid forms hydrogen ions and hypochlorite Write the reaction involved in chlorination.
- What is the Ka of this reaction?
- Which species in this reaction is most effective in killing bacteria?
- At what pH range is this equilibrium found.?
- What happens to the equilibrium if the pH is a) lower than 6 b) higher than 9.
- Why is it not desirable to have the pH too low?
- Why are calcium ions added to pool water. Your answer should include reference to solubility (Ksp) and Le Chatelier's principle.
- When I was at school many, many years ago, my mate Dane Greenwood had a pool and a green tinge in his hair ( and yes his name really was Greenwood). Explain in detail what caused Dane's green hair.
- Pool water is buffered to maintain the pH within the ideal range of 7.2 - 7.8. What is added to pool water to buffer the pool water.
- How do you think the carbonate ions buffer the pool? Hint : what is the reaction of carbonate ions in water.
- How is most chlorine lost from pool water?
- Explain how isocyanuric acid prevents the loss of chlorine from pools due to sunlight.