Background
To carry out our experiment we used 3 different types of orange juices, and we also used 0.1% of vitamin C solution. The aim of our experiment was to see how much DCPIP was needed to be added to make the orange juices turn back to the orange colour and the DCPIP to decolourise once the 0.1% of vitamin C was added. DCPIP is a blue dye in its non-reduced form; it becomes colourless when it gains electrons. Vitamin C is an anti – oxidant, this is found mainly in fresh fruit and vegetables. The main use of Vitamin C is that it neutralises free radicals, which can cause damage to cells, including cells in the cardiovascular system
Planning
My aim in this experiment is to investigate how much juice is required to decolourise 1cm3 of 0.1%of DCPIP solution.
Prediction
Before I started the investigation I made sure I did a hypothesis so that I would be able to refer back to it in the conclusion at the end. Below is my hypothesis:
My hypothesis is that: ‘there will be less’ Don Simon’ juice needed to decolourise the DCPIP, the other juices will require more juice to decolourise the DCPIP’
Fair Test
I will have to make sure that I will be carrying out a fair test. This is to ensure that anything affecting the amount needed to decolourise the DCPIP is due to what I have changed (independent variable) and nothing else. Below I have listed the independent variables as well as those factors which should be kept the same. Independent Variable: * The Juices * Amount of Juice added to the DCPIP
Dependent Variable: * The amount of DCPIP put in the test tube * 1% of DCPIP * 0.1% of vitamin C solution
Fixed Variables: * The volume of DCPIP poured into the test tube * Keeping a fixed volume of the DCPIP ensures that the decolourisation of the DCPIP is only because of the amount of juice added and not the different amount of DCPIP that is present *