To see what temperature is the best for cleaning tea stained cloth - I am going to use a Safeway, biological washing powder.

I am going to put 50 ml of 40 c in a beaker with 3 mm of washing powder with one piece of tea stained cloth in each. Then I am going to put each of the beakers into a water bath of different temperatures. I am going to leave them in the bath for ten minutes. While they are in the bath I am going to stir them. For this experiment I will need five pieces of tea stained cloth, five lots of 3mm of washing powder, five beakers, one thermometer, a water bath, a clock and a stirring rod.    

Here is a diagram of the equipment:

Results:

I think my results are wrong because the normal temperature for biological washing powder is 40 c, but as you can see in the results table 40 c wasn’t very clean.  

If my results are right then only two is wrong, which is 50 c and 55 c, because if it is the higher the temperature the cleaner it gets then 5o c and 55 c should be the other way around.

Evaluation:

To get more accurate results I would do the experiment at least twice. If I did the experiment again I would do the whole thing different e.g. I would put the tea stained cloth into a beaker with different temperatures and just leave them for ten minutes. To improve my experiment I would do a light test at the end to see how clean the cloth was. The light test would work by washing the cloth then putting a torch e.c.t. behind the it, the more the that comes through the cleaner it is. I would also go up 10 c instead of 5 c that way there should be more of a change in cleanness. I would also make it fair by doing the experiment all at the same time and on the same day.