PRACTICAL SKILLS ON THE TOPIC DETERMINATION OF RESIDUAL

CHLORINE IN WATER

PURPOSE

• This skill is required when selecting the dose of chlorine, as well as to assess the quality of chlorinated water.

EQUIPMENT NEEDED:

• The study chlorinated water Chemical glassware reagent

SEQUENCE OF ACTIONS

• 1- Pour into a flask with 250 ml of water under investigation

2- Add 5 ml of 5% potassium iodide, 5 ml of buffer solution and 1 ml of 1% starch solution.

• 3- Perform the titration of the sample 0.001% solution of sodium hyposulphite to blue discoloration in the flask.

• 4- Calculate the residual chlorine by the formula: X = (nx K x 0,355 x 1000): 250 mg / l, where n- number of hyposulphite (ml) that went to the titration of the sample K - correction factor titer hyposulphite.

• 5 Rate the results obtained with the hygienic standards of residual chlorine.