Effect of temperature on Vitamin C Engineering Lab Report (Lab Report Sample)

Skills 1001BMS: Experimental Design & Assessed Skills Lab (CW2 & CW3)
Determining Vitamin C Concentration by Redox Titration Using Iodine Solution
Introduction
This method determines the vitamin C concentration in a solution by a redox titration using iodine. Vitamin C, more properly called ascorbic acid, is an essential antioxidant needed by the human body (see additional notes). As the iodine is added during the titration, the ascorbic acid is oxidised to dehydroascorbic acid, while the iodine is reduced to iodide ions.
ascorbic acid + I2 → 2 I− + dehydroascorbic acid
Due to this reaction, the iodine formed is immediately reduced to iodide as long as there is any ascorbic acid present. Once all the ascorbic acid has been oxidised, the excess iodine is free to react with the starch indicator, forming the blue-black starch-iodine complex. This is the endpoint of the titration.
Equipment Needed
Burette and stand
250 mL volumetric flask