To start, pour 30 milliliters (mL) of Lugol's solution into a 500 mL graduated cylinder. Add enough distilled water to bring the level of fluid to 300 mL. Slowly pour the diluted solution into the amber glass bottles, using a funnel. Store the bottles in a dark place, keeping the bottles …show more content…
Once this happens the titration is done.
Record the final level of the iodine solution remaining in the buret, after titration.
The difference between the initial level and the final level is the amount of iodine titration solution needed to create a reaction with the vitamin C.
Rinse out and dry the Erlenmeyer flask.
Repeat step 17-26 three times with the Vitamin C standard solution. You should get results that are within about 0.5 mL of each other. If you do not, repeat this step until you have three results that are within about 0.5 mL of each other.
Be sure to check the level of the iodine solution in the buret before each trial. Remember, if the level is below the 35 mL mark, carefully add more iodine solution to the buret (until it is between the 5 mL and 35 mL marks). Record the new level.
Prepare juice from each fruit or vegetable for testing.
Use the juicer to extract 60 mL juice from each food tested. Remove any stems or seeds from each of the types of produce.
You need 20 mL of juice per titration, and you should do at least three titrations per food, so you will need at least 60 mL