Determination of Ascorbic Acid in Vitamin C Tablets

Determination of Ascorbic Acid in Vitamin C Tablets

Jianyi Chen

Partner: Michael

Chemistry 1290-020

5 March 2015

TA: Sunayana Kapil

Purpose:

The primary purpose of this experiment was to determine the amount of ascorbic acid in a Vitamin C tablet through a process called titration. Another purpose of this experiment was to determine the pH level of different solutions by using different indicators and litmus paper. Learning about this type of analysis was important in an everyday context because we can use these techniques to determine the amount of acid in the tablets that patients would have to take; thus, determining how it can affect them. Also, we can also determine what the pH level of different solutions are so we know how acidic or basic something is.

Safety Information:

        Many of these chemicals can be potentially harmful so prevent these chemicals from eyes, skin, clothing, and ingesting. If any of these chemicals are spilled the laboratory instructor must be informed. The solution, NaOH, is toxic and corrosive, and phenolphthalein solution is flammable and an irritant (Kippenhan, 2015). Safety goggles and proper attire should be worn while in the lab. This would include shirts that would cover the shoulders, pants that cover legs all the way down to the shoes, and shoes that are worn must be closed toed shoes. The experiment must be performed in the fume hood, and students should use caution when using these potentially harmful reagents.

Materials:

Analytical balance

Mortar and pestle

Two sheets of weighing paper

Two 150 mL Erlenmeyer flasks

Wax pencil

One 600 mL beaker

One 100 mL beaker

Buret

Buret clamp

Ring stand

Eyedropper

Well plate

Red and blue litmus paper

Chemicals:

One 500 mg Vitamin C tablet

Vitamin C solution (in water)

0.11834 M sodium hydroxide (NaOH)

0.1 M acetic acid (CH3COOH)

0.1 M ammonium hydroxide (NH4OH)

0.1 M ammonium chloride (NH4Cl)

0.1 M sodium acetate (CH3COONa)

0.1 M sodium carbonate (Na2CO3)

One bottle each of phenolphthalein, thymol blue, methyl orange, bromocresol green indicator