Determination Of Vitamin C Concentration By Titration Lab Report Chegg
Vitamin C, also known as L-ascorbic acid, is a vital nutrient in human diets. It is an antioxidant that helps to protect the body from damage caused by harmful molecules called free radicals. The recommended daily intake of vitamin C for adults is 75-90 mg. However, it is possible to consume more than the recommended daily intake of vitamin C through supplements or fortified foods. Therefore, it is important to determine the concentration of vitamin C in these products.
What is Titration?
Titration is a technique used to determine the concentration of a substance in a solution. It involves adding a solution of known concentration (the titrant) to a solution of unknown concentration (the analyte) until the reaction is complete. The point at which the reaction is complete is called the endpoint. The volume of the titrant required to reach the endpoint is used to calculate the concentration of the analyte.
Titration of Vitamin C
The concentration of vitamin C in a solution can be determined by titration with an oxidizing agent such as iodine. The reaction between iodine and vitamin C is as follows:
C6H8O6 + I2 → C6H6O6 + 2I-
In this reaction, iodine is reduced to iodide ions, while vitamin C is oxidized to dehydroascorbic acid. The reaction is carried out in the presence of starch, which acts as an indicator. Starch forms a blue-black complex with iodine. When all the vitamin C has reacted with iodine, the excess iodine reacts with the starch to produce a blue-black color. This is the endpoint of the reaction.
Experimental Procedure
The experimental procedure for determining the concentration of vitamin C by titration is as follows:
- Weigh out a sample of the vitamin C solution and transfer it to a volumetric flask. Add water to make up the volume to the mark on the flask.
- Pipette a known volume of the vitamin C solution into a conical flask.
- Add a few drops of starch solution to the conical flask.
- Titrant (iodine solution) is added to the conical flask until a blue-black color is observed.
- Note the volume of the titrant required to reach the endpoint.
- Repeat the titration two more times and calculate the average volume of the titrant required to reach the endpoint.
The concentration of vitamin C in the solution can be calculated using the following formula:
Concentration of Vitamin C (mg/L) = (Volume of Titrant x Concentration of Titrant x 1000) / Volume of Sample
Results
The results obtained from the titration experiment can be used to calculate the concentration of vitamin C in the sample. The concentration of the titrant used in the experiment is known. Therefore, the concentration of vitamin C can be calculated using the formula provided above.
Conclusion
The determination of the concentration of vitamin C by titration is an important laboratory technique. It can be used to determine the concentration of vitamin C in various products, including supplements and fortified foods. The experiment involves the use of an oxidizing agent (iodine) and an indicator (starch) to determine the endpoint of the reaction. The results obtained from the experiment can be used to calculate the concentration of vitamin C in the sample. This information is crucial in ensuring that individuals do not consume more than the recommended daily intake of vitamin C.