Final answer:
In titrating vitamin C with KIO3, a stoichiometric amount of I3 is produced and back titrated with thiosulfate, involving key principles of stoichiometry, redox reactions, and quantitative analysis.
Step-by-step explanation:
When titrating vitamin C with KIO3 (Iodate), a redox reaction occurs in the presence of KI and HCl. A stoichiometric amount of I3 is produced, which can then be back titrated using a solution of thiosulfate (S₂O3²-) as the reducing agent. This process involves a sequence of reactions that provide quantitative information about the amount of vitamin C in the sample. Standardization is done using a primary standard, ensuring the accuracy of the titrant. The end point of the titration is determined visually by the color change induced by adding starch to the solution. This titration experiment is an important application of analytical chemistry that demonstrates the principles of stoichiometry, redox reactions, and quantitative analysis.