Colorimeter
Introduction
We had 3 samples of apple juices which were brought from 3 different supermarkets. 25 % is the FSA guide lines for the level of apple juice in the carton
Aim
The aim was to carry out an investigation to see what percentage of water was added to the samples of juice has and if level is within of below the FSA guidelines.
Equipment
Clamp stand
2 Burette
Plastic pipettes
Colorimeter
12 cuvettes
Test tube rack
9 Test tubes
Marker
2 100ml beaker

Chemicals
Pure apple juice
3 samples for 3 different supermarkets labelled A, B and C
Deionised water Method
First the burettes where clamed onto the clap stand one of the burette was filled with deionised water to the mark zero and the other was filled with pure apple juice. The test tube where then labelled from 1 to 6 and then these test tube different concentration of solution was prepared. The concentration that where produced are shown below in the table and the table also shows how the concentrations where produced. Test tube number | 1 | 2 | 3 | 4 | 5 | 6 | Volume of pure apple juice (standard) (cm3) | 10 | 8 | 6 | 4 | 2 | 0 | Volume of water (cm3) | 0 | 2 | 4 | 6 | 8 | 10 | Concentration (M) | 1 | 0.8 | 0.6 | 0.4 | 0.2 | 0 | Percentage concentration (%) | 100 | 80 | 60 | 40 | 20 | 0 | Absorbance (Abs) | 0.36 | 0.26 | 0.21 | 0.14 | 0.06 | 0.00 |

The percentage of the concentration was calculated. Then firstly the cuvette was sat at 400mm and to make sure it’s working properly deionised water was put in to a cuvette using a pipette. Then the cuvette was placed in the colorimeter making sure that the little arrow on the cuvette is facing you. The R button was then pressed so that the water was run as a reference this was don’t after every test and the result was recorded in a table below. The sample for test tube 5 was put into another cuvette using a pipette witch was then put in a cuvette making sure the arrow on the cuvette faces you. The t for test button was then pressed the result way recorded. This was done for all rest of the concentrating and a graph was drawn. Then the same process was carried out for the supermarket sample but different concentrations weren’t made as we wanted to find out what’s the concentration the supermarket sample. The graph was then used to work out