CP 02 - Investigate the vitamin C content of food and drink

Independent variable

Independent variable

Type of Fruit juices

Dependent variable

Volume of fruit juice to make dcpip solution colorless

Equipment list

• 1% DCPIP solution

• 5 cm³ syringes

• Test tubes

• Test tube rack

• Pipettes

• Different fruit juices

• 1% vitamin C solution

Method

1. Use a pipette to transfer 1 cm³ of DCPIP solution to a test tube.

2. Fill a 5 cm³ syringe with 5 cm³ of vitamin C solution.

3. Add the vitamin C solution from the syringe one drop at a time the DCPIP, being sure to gently shake addition.

4. Stop adding the vitamin C once the blue DCPIP colorless.

5. Record the volume of the solution that has been added to cause the color change.

6. Repeat steps 1-5 to obtain 2 further results for the vitamin C solution and then calculate a mean.

7. Then repeat steps 1-5 using each of the fruit juices of the vitamin C solution.