Assay of Ascorbic acid

Reagents Required

1.0M Sulfuric acid
0.05M Iodine

Procedure

Weigh accurately about 0.1 gm of the sample and dissolve in a mixture of 100 ml freshly boiled and cooled water and 25 ml of 1M sulfuric acid. Immediately titrate with 0.05M iodine, using the starch solution as indicator until a persistent blue-violet color is obtained. Each ml of 0.05M iodine is equivalent to 0.008806 gm of ascorbic acid.
Calculation
                                         BR X Actual molarity X 0.008806 X 100
% of Ascorbic acid = ----------------------------------------------------
                                                      0.05 X Wt. of Sample
BR= Burette Reading