Experiment 10 - Vitamin C Determination
Part C - Vitamin C Determination in Fruit
- Transfer approximately 125 mL of fruit juice into a clean
and dry beaker. Pipet 50.00 mL (two 25.00 mL) into a 250 mL erlenmeyer
flask. Add about 10 drops of starch indicator.
- Titrate the vitamin C in the fruit juice with the iodine solution standardized
in Part B to a blue end point.
- Read the buret carefully to determine the quantity of iodine used to reach
the end point. Record the volume of the iodine solution used.
- Repeat the above procedure until you get titration volumes which agree to
within +/- 0.1 mL.
- Clean the burets and leave them filled with distilled water. Replace the
top on the buret.
- Iodine solution can stain clothing and skin. To wash off stain, apply the
thiosulfate, S2O32-, ion solution to the
stained area and rinse with water.
- Discard any remaining iodine solution in the waste
iodine container provided.