Experiment 10 - Vitamin C Determination

Procedure:

Part C - Vitamin C Determination in Fruit Juice

1. 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.
2. Titrate the vitamin C in the fruit juice with the iodine solution standardized in Part B to a blue end point.
3. Read the buret carefully to determine the quantity of iodine used to reach the end point. Record the volume of the iodine solution used.
4. Repeat the above procedure until you get titration volumes which agree to within +/- 0.1 mL.

Clean Up

1. Clean the burets and leave them filled with distilled water. Replace the top on the buret.
2. Iodine solution can stain clothing and skin. To wash off stain, apply the thiosulfate, S₂O₃^2-, ion solution to the stained area and rinse with water.
3. Discard any remaining iodine solution in the waste iodine container provided.