Organic Chemistry 3

I wanted to share a good question with you. It uses your redox chemistry skills as well as theoretical atomic valance calculation of organic substances. However, nobody managed to solve this problem as it is sufficiently time-consuming and somewhat difficult.

Write the full-balanced equation of potassium sodium tartrate (KNaC4H4O6; see the attachment) with potassium permanganate in the presence of nitric acid. Note that the orientations of alcoholic OH groups are not important in this question.

Hint: I can give a reaction of oxalic acid (HOOC-COOH) in this way:

5*[C(3+) ---> C(4+) + e(-)]
Mn(7+) + 5e(-) ---> Mn(2+)
-----------------------------------------------
5C(3+) + Mn(7+) ---> 5C(4+) + Mn(2+)
10C(3+) + 2Mn(7+)---> 10C(4+) + 2Mn(2+)

5 H2C2O4 + 2 KMnO4 + 6 HCl ---> 10 CO2 + 2 MnCl2 + 2 KCl + 8 H2O

Hint2: Note that tartrate contains two kinds of C atoms; alcoholic and carboxylic, so two different sets of redox chemistry is involved altogether.

If you have enough time to deal with a challenging question, give it a try.