Sciencemadness Discussion Board

oxalic acid synthesis

condennnsa - 7-7-2010 at 07:43

I need some oxalic acid, but i can't find any to buy.

What would be the easiest way for the home chemist to oxalic acid?

I remember reading somewhere that it can be prepared from sucrose and nitric acid, with a V2O5 catalyst ... but that it also works without the catalyst for a lower yield.

Has anyone tried this procedure? Is it worthwhile?

not_important - 7-7-2010 at 07:46

It's been covered here before, several threads. Try doing a little searching and you'll find them.

JohnWW - 7-7-2010 at 07:59

Sucrose + nitric acid is liable to give you the nitrate ester, sucrose octanitrate, or a partly esterified form, which like cellulose nitrate (gun-cotton etc.) is an high explosive, so be VERY careful.
See: http://www.sciencemadness.org/talk/viewthread.php?tid=17 , also http://www.freepatentsonline.com/2081161.html , http://www.freepatentsonline.com/2165435.html , http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=1982... , http://www.caslab.com/Sucrose_octanitrate__3552-_-/ .

Magpie - 7-7-2010 at 08:03

http://www.sciencemadness.org/talk/viewthread.php?tid=12832#...

Picric-A - 7-7-2010 at 10:33

Quote: Originally posted by JohnWW  
Sucrose + nitric acid is liable to give you the nitrate ester, sucrose octanitrate, or a partly esterified form, which like cellulose nitrate (gun-cotton etc.) is an high explosive, so be VERY careful.
See: http://www.sciencemadness.org/talk/viewthread.php?tid=17 , also http://www.freepatentsonline.com/2081161.html , http://www.freepatentsonline.com/2165435.html , http://pubchem.ncbi.nlm.nih.gov/summary/summary.cgi?sid=1982... , http://www.caslab.com/Sucrose_octanitrate__3552-_-/ .


Not a chance of forming the nitrate if you use 40% nitric acid for the oxidising agent as you are supposed to!
Its true, nitrates may form if WFNA is used but you would have to be retarded to try that :P

The WiZard is In - 7-7-2010 at 10:59

Quote: Originally posted by condennnsa  
I need some oxalic acid, but i can't find any to buy.



Buying is the antithesis of experimentalism. However, if you are willing
to give into the dark side ... you can buy a 500kg lot.
For sale by a NY City charity on eBay.

The WiZard is In - 7-7-2010 at 11:11

Quote: Originally posted by condennnsa  
I need some oxalic acid, but i can't find any to buy.

What would be the easiest way for the home chemist to oxalic acid?

I remember reading somewhere that it can be prepared from sucrose and nitric acid, with a V2O5 catalyst ... but that it also works without the catalyst for a lower yield.

Has anyone tried this procedure? Is it worthwhile?



-----
What you remembered can be found in Thorpe's
Dictionary of Applied Chemistry Try the 1922 ed.

Vogelzang - 7-7-2010 at 13:00

http://www.google.com/#q=oxalic+wood&hl=en&sa=2&...

http://files.buildsite.com/dbderived-f/dap/derived_files/der...

[Edited on 7-7-2010 by Vogelzang]

Picric-A - 7-7-2010 at 13:31

There are hundreds of wrriten examples of this reaction, ie, vogel.
The yield is not the best (off the top of my head ~30% at best) however sugar and nitric is cheap and to most, readily available! I am surprised you can buy oxalic acid, it is cheap and it is in just about every wood preservative/treatment you can buy!

entropy51 - 7-7-2010 at 15:42

Quote: Originally posted by condennnsa  
I need some oxalic acid, but i can't find any to buy.


In my part of the United States, all of the hardware stores sell good quality oxalic acid as wood bleach.

Picric-A - 8-7-2010 at 10:19

Quote: Originally posted by entropy51  
Quote: Originally posted by condennnsa  
I need some oxalic acid, but i can't find any to buy.


In my part of the United States, all of the hardware stores sell good quality oxalic acid as wood bleach.


I'll second that for the UK.

The WiZard is In - 8-7-2010 at 16:32

Quote: Originally posted by The WiZard is In  

What you remembered can be found in Thorpe's
Dictionary of Applied Chemistry Try the 1922 ed.


Sorry I forgot to add - you can access it at Google.com/books.

Random - 2-11-2010 at 00:53

Can I use nitrate salt mixed with hcl instead of pure nitric acid?

Picric-A - 2-11-2010 at 01:42

Quote: Originally posted by Random  
Can I use nitrate salt mixed with hcl instead of pure nitric acid?


Yes, i am sure, however yields would be worse still and the product would be harder to extract.

Try boiling down a 100ml solution of ethylene glycol in 30% nitric acid until 30ml remains then cool in ice. Oxalic acid will ppt. Yield ~72%.

Random - 2-11-2010 at 11:07

actually i am thinking about sucrose route with nitrate salt and hcl

not_important - 2-11-2010 at 11:15

Quote: Originally posted by Random  
Can I use nitrate salt mixed with hcl instead of pure nitric acid?


some metal or ammonium nitrate MNO3 + HCl <==> MCl + HNO3

So you get a mixture of the two salts, and the two acids. And HNO3+HCl is aqua regia, or an approximation thereof. Release Cl2 and NOCl.


Ethylene glycol plus hypochlorite bleach with a nickle salt catalyst also works though the yields are lower than using pure HNO3 of the proper concentration. Add the glycol slowly, with stirring. There's at ;east one thread on bleach+Ni as an oxidiser.

Random - 4-11-2010 at 11:35

I will check that metal too, just I am interested in hcl/nitrate salt method the most because that is what i mostly have. There should be no explosive or very toxic things generated with hcl-nitrate salt and sugar?

not_important - 4-11-2010 at 11:41

As I said - HCl + a nitrate makes some NOCl + Cl2, both reasonably nasty without good ventilation. just for starters; plus it wastes the materials as some of the nitrate is destroyed in those side reactions. The mixture is not a good one for anything but dissolving certain metals like gold.

AndersHoveland - 6-12-2011 at 16:23

I already posted this somewhere else, but I will repeat it again, to make it easier to find it in a search, since it could be potentially useful.

Wurtz found that ethylene glycol fused with solid potassium hydroxide yielded mostly potassium oxalate and hydrogen gas. The yield of hydrogen was 58% of that required by the below proposed reaction
C2H6O2 + 2KOH --> K2C2O4 + 4H2

"THE LIBERATION OF HYDROGEN FROM CARBON COMPOUNDS", Shipley Fry, Else L. Schulze, Helen Weitkamp
J. Am. Chem. Soc., 1924, 46 (10), pp 2268–2275

Adas - 10-12-2011 at 10:59

You can also use copper to oxidise it, but this is too slow and unefficient.

Hexavalent - 5-1-2012 at 14:31

Quote: Originally posted by Picric-A  
Quote: Originally posted by entropy51  
Quote: Originally posted by condennnsa  
I need some oxalic acid, but i can't find any to buy.


In my part of the United States, all of the hardware stores sell good quality oxalic acid as wood bleach.


I'll second that for the UK.


http://www.ebay.co.uk/itm/500g-Oxalic-acid-great-cleaner-rus...