Sciencemadness Discussion Board

Ascorbic acid question

axehandle - 5-8-2004 at 11:25

Many months ago, I ordered 4kg of ascorbic acid to be used as a fuel in a propellant mix. Now I'm curious as to if it can be used "as is" for vitamin C drinks.

I've understood that L-ascorbic acid is the same as vitamin C, but what I don't now is if my powder is likely to be another type of ascorbic acid. It doesn't say. I ordered if from a food company, btw.

Anyone know?

chemoleo - 5-8-2004 at 11:35

If you got it from a food company, it is most likely edible. 4kg is a lot. How much was it if I can ask?
No, there is only one type of ascorbic acid/Vitamin C. Also, ascorbic acid is mainly synthesised for food anyhow, so it would be very unlikely for you to get an impure product. You can always ring the company where u got it from of course.

If you have that much of it, try some interesting reductions. Mix it with CuSO4 or acetate, and heat.
A nice copper I oxide precipiate will ensue! (or maybe copper itself, can't remember)

axehandle - 5-8-2004 at 11:40

I don't recall the exact price, but it was something like (the equivalent of) 50 Euro (about 12 Euro / kg).

And it is food grade, I remember asking particularly about that.

If there's only one type of ascorbic acid, why is it call "L-ascorbic acid"?

Its possible use as a reductant is though-provoking -- there may be many interesting reactions to try...

Quote:

If you have that much of it, try some interesting reductions. Mix it with CuSO4 or acetate, and heat.
A nice copper I oxide precipiate will ensue! (or maybe copper itself, can't remember)

Would the analog reaction of the lead acetate then be a viable route to PbO from PbAc?


[Edited on 2004-8-5 by axehandle]

[Edited on 2004-8-5 by axehandle]

chemoleo - 5-8-2004 at 12:16

Oh, the L simply describes the chiral character of the ascorbic acid. There are two forms, L and D (dextrorotary and levorotary), for rotating polarised light left or right, which depends where groups are spacially on the spiral carbon.
I would attach a structure, but can't do it from here.
Here's a quick crashcourse on optical rotation, and chirality: http://www.sparknotes.com/chemistry/organic3/stereoisomers/s...
Anyway, D/L ascorbic acid are chemically the same. As with sugars, however, they may or may not be recognised by proteins, depending on which form it is, as proteins often recognise ligands in 3 D space.



As to reduction of PbAc2 - u would get lead metal. There aren't any lesser oxidation states than Pb2+. But the reduction potential of ascorbic acid may not be great enough to achieve that.