Talk:Oxalic acid
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[edit] Radiocarbon Dating
Perhaps mention of Oxalic acid's use in radiocarbon dating?
"The principal modern radiocarbon standard is N.I.S.T (National Institute of Standards and Technology; Gaithersburg, Maryland, USA) Oxalic Acid I (C2H2O4). Oxalic acid I is N.I.S.T designation SRM 4990 B and is termed HOx1. This is the International Radiocarbon Dating Standard. Ninety-five percent of the activity of Oxalic Acid from the year 1950 is equal to the measured activity of the absolute radiocarbon standard which is 1890 wood. 1890 wood was chosen as the radiocarbon standard because it was growing prior to the fossil fuel effects of the industrial revolution. The activity of 1890 wood is corrected for radioactive decay to 1950. Thus 1950, is year 0 BP by convention in radiocarbon dating and is deemed to be the 'present'. 1950 was chosen for no particular reason other than to honour the publication of the first radiocarbon dates calculated in December 1949 (Taylor, 1987:97)." http://www.c14dating.com/agecalc.html
and
"A 14C reference material or standard was chosen to represent as closely as possible the 14C content of carbon in naturally growing plants. The 14C content of the standard material itself does not need to be, in fact is not, equal to the standard 14C content. The definition of the standard 14C activity is based on 95% of the specific activity of the original NBS oxalic acid (Ox1) in the year AD 1950 (KarlZn et al. 1966), as will be discussed in more detail later." http://www.radiocarbon.org/Subscribers/Fulltext/v41n3_mook_vdplicht_227.html
[edit] Cleanup
Re:Foods that contain significant quantities of oxalic acid include cocoa, chocolate, most nuts, most berries, rhubarb, beans, and beets, among 'many others'.
In addition to its natural ...
- If there are many others, they need to be added, hence 'clean' template. User:fabartus
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- I removed the phrase, and many others because the list begins with includes (stating that the list is not complete). I then removed the clean tag from this page. RJFJR 17:15, September 3, 2005 (UTC)
- That ought to stick. You can find sugar in everything, but it's hard to find in Coffee.
I can think of four relevant kinds of list: short, long, exhaustive, and complete. Brewhaha@edmc.net 20:12, 7 May 2007 (UTC)
[edit] Food high in oxalic acid
I found this page [1] and I merged the parsley and spanish into this page based on [2] but I coundn't confirm tea nor that cooking increases oxalic acid. -- W P Talk 09:19, 18 October 2005 (UTC)
[edit] Melting point/Boiling point
There is some discrepency between sources on these values. It appears that oxalic acid decomposes at 191 °C, and this is sometimes listed as a melting point: however other sopurces list a lower temperature as a sublimation point. A full review would be welcome, I will do one if I get a chance. Physchim62 (talk) 12:27, 21 December 2005 (UTC)
[edit] Tests
- Some tests for oxalic acid can misidentify ascorbate as oxalic acid.
- What tests...? mastodon 16:06, 23 May 2006 (UTC)
- Titration with potassium permanganate will confuse ascorbate and oxalic acid, as will most test based on reducing power: the solution is to run a second test for strong reductants using, for example, iodine. Oxalic acid is only a weak reductant, and it needs an oxidant as strong as permanganate to react. Physchim62 (talk) 07:17, 24 May 2006 (UTC)
- Thanks, I'll include this in the article mastodon 22:11, 29 May 2006 (UTC)
[edit] Probably my favourite acid
Thoughts? —The preceding unsigned comment was added by 210.50.227.40 (talk • contribs) .
- I'm thinking I couldn't care less what your favorite acid is, O anonymous person. —Keenan Pepper 21:18, 29 July 2006 (UTC)
Haha someone replied. I guess people do look on the discussion pages for random acids. —The preceding unsigned comment was added by 211.27.89.18 (talk • contribs) .
Well, it's got the nicest name, but HCl is the best! :) 82.40.75.55 22:58, 7 June 2007 (UTC)
[edit] pKa Values in Chembox
The values given as I write this do not specify a temperature. I am replacing them with 25°C values from 44th ed. of CRC Handbook of Chemistry and Physics and that jibe with values given in 10th ed. of Lange's Handbook of Chemistry. I did find pK values that match what was there (1.27 and 4.27) in Merck Index, but it did not give temperature either. Karlhahn 17:10, 20 August 2006 (UTC)
[edit] LD50
Under "hazards" the LD50 is given as 7.5g/Kg but under safety it's 378mg/Kg. These are VERY different - which is right?
- .378 g/kg or 7.5 g/kg? That might be a raynj given from animal studies where the Cat and the Rabbit differ, and if so, then that's what should be written. Brewhaha@edmc.net 19:45, 7 May 2007 (UTC)
[edit] I didn't know it's dangerous
I eat sorrel any chance I get - I like its sour taste.
I guess that oxalic acid is as toxic as anything else - if you'll eat too much, you'll not feel good :) —The preceding unsigned comment was added by 87.245.187.51 (talk) 08:55, 26 February 2007 (UTC).
[edit] is it a strong or weak acid???
I have tried to add some oxalic acid and some acetic acid into copper(II)carbonate respectively, in order to test their strength. It was quite disappointing to find that oxalic acid react even slower than acetic acid......Is it really true that oxalic acid is "about 10,000 times stronger than acetic acid."? I am frustated with that.Superdvd 09:29, 11 March 2007 (UTC)
- pH and reaction rates are only related. Copper oxalate is less soluble, so it has to precipitate, too. A better question is whether Oxalate can precipitate Copper(II) out of the Acetate, and Oxalate should be the major product with sufficient time and concentration. I applaud the orijinal research in this case, because it's not part of the article, which should contain more about real world implications. It is a weak acid compared to inorganics. Brewhaha@edmc.net 20:03, 7 May 2007 (UTC)
[edit] Bad Sentence
"For this reason, a second test for strong reductants using, for example, iodine."
Makes no sense to me. Can anyone explain? Or is it a gramatical error? 82.40.75.55 22:57, 7 June 2007 (UTC)
(Edit to sign)
[edit] The Ionic States of it
I believe that this article could have included the factors that affect ionisation of oxalic acid.Also oxalic acid yields 2 protons while the other dicarboxylic acids don't yield two protons.Hence the factors for oxalic acid to yield both the protons could have been explained along with Ka values ..
- The chem-data box gives the first and second pKa values, which tell you all you need to know about its diprotic behavior at 25°C. As for other dicarboxylic acids, they too have two pKa values, and thus, some fraction of each of them will yield two protons. See succinic acid as an example. Karl Hahn (T) (C) 12:10, 3 August 2007 (UTC)
[edit] Missing the melting point.
This article doesn't seem to mention the melting point or boiling point of Oxalic acid. Does anyone happen to know what they are? Larrythefunkyferret 21:56, 12 September 2007 (UTC)
[edit] Household uses?
I used to put a tablespoon or so of oxalic acid in my dishwasher to remove hard water stains from my dishes. At that time I had a dishwasher with a plastic interior. I now have one with a stainless steel interior; can anyone tell me if that is problematic? I don't want to damage my new dishwasher! Thanks! 70.146.77.67 (talk) 21:21, 11 April 2008 (UTC)
