Required Practical: Analysis and Purification of Water


To analyse samples of water from different sources by measuring pH and identifying dissolved substances. The samples will then be purified using simple distillation to obtain potable water.


Analysing A Sample Of Water

1. Test the pH of the water sample using universal indicator paper.

2. Accurately weigh and record the mass of an empty evaporating basin accurately to two decimal places.

3. Pour 50 cm³ of the water sample into the evaporating basin.

4. Heat the evaporating basin on a tripod and gauze using a Bunsen burner until all the liquid evaporates.

5. Allow the evaporating basin to cool, then weigh it again.

6. Calculate the mass of dissolved solids remaining in the evaporating basin. After this, record your findings in a table, like the example below:

Water samplepHMass of remaining solid (g)

Purifying A Sample Of Water

1. Pour the water sample into a conical flask and set up the distillation apparatus.

2. Heat the water using a Bunsen burner until it boils, then reduce the heat to maintain a gentle boil.

3. Collect approximately 2 cm³ of distilled water from the cooled test tube.

4. Analyse the distilled water by determining its boiling point.


The distilled water is pure, containing no dissolved solids, and has a pH of 7.


This experiment demonstrates that simple distillation can effectively produce pure water from impure sources, creating potable water for various applications.