Three different methods for showing that the water out of a river is polluted from sewage disposed in there are as follows; titrations are the first method that can be used. This method works by slowly adding a titrant to an unknown solution until the solution neutralises and changes colour due to the indicator added to it. The next method to determine if a river is polluted is by using ph paper. This reacts to any acid or alkali in the water, this method is quick and easy to perform and can be very accurate. The last method that can be used is an electronic ph meter, this is also quick to perform and if high quality equipment is used then there will be instant results that are very precise.
1. I used a pipette is used to measure accurately a volume of this solution for example, 10cm3. I used a Safety pipette filler is used to draw solution into the pipette. This is emptied into a conical flask.
2. I added a few drops of an indicator into to the conical flask. This will show a change of colour when the titration is complete.
3. A second chemical is placed in a burette. This other solution is of a chemical that will react with the synthesised chemical sample in the conical flask. Often the solution in the burette is an acid or alkali, and it must be of a precise, known concentration.
4. The solution from the burette is run into the conical flask. The solution is added one drop at a time, with swirling to mix the solutions as the end-point is approached. Eventually, a colour change shows that the correct amount has been added to react completely with the synthesised chemical in the sample.
5. The volume of solution added from the burette is noted. The titration results can then be used to calculate the amount of the synthesised chemical in the sample, and therefore find its purity.

The second method was using ph paper.

The method;
1. Place the ph paper into the beaker filled with solution.
2. Leave for a few minutes.
3. Pull out the paper.
4. Compare the colour of the paper to the sheet.
5. Record the results.

My next method for finding out if a water system is polluted is by using a ph meter. This piece of equipment is used to measure ph of different substances with high accuracy.

Sample: ph