Final answer:
In the titration of vitamin C with KIO3, each iodate ion (IO3-) added reacts to form 3 molecules of iodine (I2) through a redox reaction with vitamin C serving as the reducing agent.
Step-by-step explanation:
When titrating vitamin C with KIO3, each IO3- that is added forms I2 (iodine). The underlying chemistry involves a redox reaction in which iodate ions (IO3-) are reduced to iodine by vitamin C, which acts as a reducing agent. In a typical titration setup, a known concentration of KIO3 solution is added to a solution containing vitamin C until the reaction is complete, which can be determined by a starch indicator or the cessation of the color change involved in the reaction.
The balanced reaction would be:
- IO3-(aq) + 5 I-(aq) + 6 H+ → 3 I2(aq) + 3 H2O(l)
In the process, each IO3- reacts with excess potassium iodide (KI) in an acidic solution to produce 3 molecules of iodine, I2.