Vitamin C Analysis

This is a back titration. That means we are titrating to find the amount of a substance (iodine, in this case) that remains in the conical flask after it reacts with our unknown (Vitamin C, in this case). We will go over the calculations in another lesson, but here is the procedure:

You will notice that this is exactly the same titration as what we did to standardise the sodium thiosulfate solution, except that we add a precise volume of our Vitamin C solution as well. The Vitamin C reacts with some of the iodine that is made when the iodate solution and iodide crystals react in the conical flask.