water+analysis

**WATER ANALYSIS** Water is an excellent solvent - but this property can be both an advantage and a disadvantage. Some of the substances dissolved in water are beneficial such as calcium ions, iodide ions and other minerals too. Others are harmful to the body. [|WATER TREATMENT FACTS] =**// TASK //**= With the members of your group write one substance which is beneficial when dissolved in water and say why it is so, and one substance which is harmful when dissoved in water and say why. Each member of the group should be careful not to write the same as the others. a substace danger for water is oil.

=//** THINK! **//= a) What is the pH of your water supply? b) What do you know about the concentration in your local water of each of the following? i) Lead, Pb2+: below or above recommended levels ii) Nitrate, NO3 -: below or above recommended levels iii) Pesticides: below or above recommended levels c) What is the hardness of your water? i) Low ii) Medium iii) High d) How many coliform bacteria per litre are there in your water supply?