Ascorbic Acid

In the following experiment, the amount of vitamin C content in Sunny D will be compared to regular Prairie Farms® orange juice, as well as a standard sample. This will determine the amount of each of these juices that should be consumed daily to achieve the recommended daily allowance to prevent a disease known as scurvy.

PROCEDURE:

First a buret was set up in a clamp and filled with 2,6-dichloroindophenol dye solution. Record the initial volume to 0.01 mL. Pipet 10 mL of standard ascorbic acid solution into a 250-mL Erlenmeyer flask. Using a 10 mL graduated cylinder, add 1.5 mL of glacial acetic acid. Add the glacial acetic acid to the 250-mL Erlenmeyer flask. Set the 250-mL Erlenmeyer flask under the buret and begin titrating the ascorbic acid solution with the dye until a light permanent pick color forms, swirl until the light pink color is permanent. Record the final volume of the 2,6 dichloroindophenol dye solution to the nearest 0.01 mL. Repeat. The values should not differ more than 0.30, if they do repeat the titration until the values are more agreeable. For this standard sample of ascorbic acid the concentration was given (0.20 mg/mL). Using the average of the 2 trials it was found that 0.16 mg of ascorbic acid per 1 mL of dye used.

Trial 1 Trial 2

Start- 3.49 mL 15.98 mL

End- 15.98 mL 28.19 mL

Amount of dye used. Trial 1- 12.49 mL Trial 2- 12.21 mL

Average: 12.35 mL

The way to figure out how much ascorbic acid is need per mL of dye is as follows:

Take the amount of ascorbic acid used x the concentration of ascorbic acid

The average of the dye used

So for the standard it would be:

10 mL x 0.20 mg/mL = 0.16 mg of ascorbic acid/mL of dye

12.35 mL of dye

Repeat the above procedure substituting Prairie Farms® 100 % pure premium orange juice 16 oz. bottle with 100% vitamin C content, instead of the standard ascorbic acid solution and record the same data.

Trial 1 Trial 2

Start- 28.19 mL 1.41 mL

End- 47.61 mL 20.91 mL

Amount of dye used. Trial 1- 19.42 mL Trial 2- 19.50 mL

Average: 19.46 mL

To figure out the amount of dye used here, take

The average dye used x 0.16 mg ascorbic aced x 1

1 mL of dye x 10 mL of orange juice

So for the orange juice is would equal:

19.46 mL x 0.16 mg x 1 = 0.31 mg of ascorbic acid/1 mL of orange juice.

1 mL of dye x 10 mL of orange juice

Then

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