Chemistry Help?

Does anyone know the mechanism for DCPIP and Ascorbic Acid? Or the Iodine-Ascorbic Acid reaction? Know it's a redox but that's about it. By mechanism I mean curly arrows, transfer of electrons? Thank you SO much!

What do you mean with DCPIP?

The only mechanism which I have found about ascorbic acid is a radical reaction. By this reaction it comes to a chain reaction. This chain reaction comes to an end when to radicals are react with each other.

In the case of the oxidation of the ascorbic acid, there are two oxygen ions with the same charge (negative) exist. These ones are the radical, superoxide radical. This radical react with ascorbic acid with formation of hydrogen peroxide, an ascorbyl radical come into being. This reaction is over when two ascorbyl radicals react with each other with formation of ascorbic acid and dehydroascrobic acid.

Hope my answer was a little bit helpful.

Do you have a diagram to show this? Thank you!

Do you mean a depiction which shows the radical reaction together with the structural formulas? I'm sorry, but I haven't!

But I can write the reaction down, if you want. First the superoxide radical come into being by homolytic cleavage of hydrogen atoms on ascorbic acid:

AscH2 -> 2 H(dot) + O2(dot) ( O2(dot) belongs to dehydroascorbic acid radical, but it is easier to use in this spelling)

The superoxide radical reacts with a hydrogen ion to hydrogen peroxide, ascorbic acid is formed to semi-dehydroascorbic acid radical:

O2(dot) + H(+) + AscH2 -> H2O2 + AscH(dot)

By this reaction a hydroxyl radical may formed too. This radical reacts with ascorbic acid with formation of water, a
semi-dehydroascorbic acid radical is formed:

HO(dot) + AscH2 -> H2O + AscH(dot)

This reaction goes on, until two semi-dehydroascorbic acid radicals react with each other. Ascorbic acid and dehydroascorbic acid come into being, the radical reaction is over:

2 AscH(dot) -> AscH2 + Asc(ox)

I hope that it was a help for you,although it is not a diagram.

Wow thank you SO much! One last question, what do you mean by Asc (ox)? Does that just mean oxidised ascorbate?

Asc(ox) is just dehydroascorbic acid which is one of the end products after radical reaction. Sorry, if it was not clear enough in my explanation before.

I'm glad that I could help you!