Volumetric Analysis of Vitamin C by Titration Essay Example
Volumetric Analysis of Vitamin C by Titration
The objective of this experiment is to use a redox reaction titration to accurately determine the amount of vitamin C in a sample of lemon juice, orange juice, or grapefruit juice.
Chemistry of Vitamin C
The chemical name for vitamin C is L-ascorbic acid. Its molecular formula is C6H8O6; its molar mass is 176.12 g/mole.
Ascorbic acid is found throughout the plant and animal kingdoms, occurring in citrus fruits, hip berries (such as rose hips), fresh tea leaves, tomatoes, broccoli, other fruits and vegetables, paprika, and the adrenal cortex of oxen. It can be obtained from any of these sources but was originally isolated from and identified in oxen. It was the first vitamin to be prepared in pure form. Ascorbic acid is a white solid that has a sharp, sour taste and dissolves in water. The pure compound is stable to air oxidation when dry, but when impure (as it is in many natural forms) it is readily oxidized when exposed to air and light. Vitamin C is a fairly strong reducing agent and decolorizes many dyes. Its aqueous solutions are rapidly oxidized by air; this reaction is accelerated in basic solution and in the presence of iron and copper ions. The vitamin-C content of juices can decrease rapidly with time once the juice is exposed to air. (Much of the information reported here about vitamin C was obtained from the Merck Index, Susan Budavari, Ed., Merck and Co., Inc., Rahway, NJ, 1989, which is a good source for physical, chemical, and physiological properties of chemicals, drugs, and biological agents.)
Vitamin C is essential to humans. It is involved in the synthesis of collagen, which constitutes about one-third of the total protein in the human body. A deficiency of vitamin C results in a disease called scurvy, which is characterized by weakness, swollen joints, bleeding gums and loose teeth, and delayed healing of wounds. Scurvy was common in sailors, who had no fresh fruits or
The objective of this experiment is to use a redox reaction titration to accurately determine the amount of vitamin C in a sample of lemon juice, orange juice, or grapefruit juice.
Chemistry of Vitamin C
The chemical name for vitamin C is L-ascorbic acid. Its molecular formula is C6H8O6; its molar mass is 176.12 g/mole.
Ascorbic acid is found throughout the plant and animal kingdoms, occurring in citrus fruits, hip berries (such as rose hips), fresh tea leaves, tomatoes, broccoli, other fruits and vegetables, paprika, and the adrenal cortex of oxen. It can be obtained from any of these sources but was originally isolated from and identified in oxen. It was the first vitamin to be prepared in pure form. Ascorbic acid is a white solid that has a sharp, sour taste and dissolves in water. The pure compound is stable to air oxidation when dry, but when impure (as it is in many natural forms) it is readily oxidized when exposed to air and light. Vitamin C is a fairly strong reducing agent and decolorizes many dyes. Its aqueous solutions are rapidly oxidized by air; this reaction is accelerated in basic solution and in the presence of iron and copper ions. The vitamin-C content of juices can decrease rapidly with time once the juice is exposed to air. (Much of the information reported here about vitamin C was obtained from the Merck Index, Susan Budavari, Ed., Merck and Co., Inc., Rahway, NJ, 1989, which is a good source for physical, chemical, and physiological properties of chemicals, drugs, and biological agents.)
Vitamin C is essential to humans. It is involved in the synthesis of collagen, which constitutes about one-third of the total protein in the human body. A deficiency of vitamin C results in a disease called scurvy, which is characterized by weakness, swollen joints, bleeding gums and loose teeth, and delayed healing of wounds. Scurvy was common in sailors, who had no fresh fruits or