Measuring Amounts of Vitamin C in Apple Juice Leah Bury, Grade 9

Problem Using titration to find out which type of apple juice (from concentrate, not from concentrate) contains the most vitamin C. Chose this experiment in order to see if there was a significant difference between types of apple juice

Research Titration- method that uses a solution with a known concentration to find the concentration of a second solution. Vitamin C- apple juice is not a natural source

Hypothesis If two different types of apple juice differ in ingredients and/or type, then they will have different amounts of Vitamin C.

Materials Apple Juice (20 mL) Apple Juice from Concentrate (20 mL) Vitamin C Tablets (125 mg) Distilled Water Iodine Solution (50 mL) Soluble Starch (.125 g)

Variables Independent- type of apple juice used Dependent- amount of vitamin C Controlled- concentration of Iodine solution

Procedure First, Iodine and distilled water were mixed to create a 25% Iodine solution. A starch indicator solution was made by adding .125 g of starch to 25 mL of distilled water. A vitamin C standard solution was made by mixing 125 mg of vitamin C with 50 mL of distilled water. The standard vitamin C solution was titrated by adding 3 drops of the starch indicator and measuring the amount of Iodine solution needed to turn the vitamin C solution black.

Procedure Then 20 mL of apple juice was titrated. After that, 40 mL of apple juice from concentrate was mixed with 40 mL of distilled water. 20 mL was titrated.

Data Amt. of Vit. C 0.06 M 0.3 M 0.1 M Vit. C Solution Apple Juice Concentrate 0.1 M

Conclusion If two different types of apple juice differ in ingredients and/or type, then they will have different amounts of Vitamin C. The hypothesis was supported: the 2 different types of apple juice contained different amounts of vitamin C. The apple juice (not from concentrate) contained the most vitamin C. The vitamin C solution contained the least vitamin C. Apple juice not from concentrate does not have any water added.

Further Experimentation Experiment can be carried further by retesting and measuring the vitamin C in other fruit juices.

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