Talk:Acetic acid/Archive 1

Mistake with acetic acid picture?

Looks like the "http://en.wikipedia.org/upload/d/d9/Acetic-acid.png" (acetic acid formula picture) needs another carbon atom.

It's okay. In organic structural formulas, symbols for carbon and attached hydrogens are usually omitted. That said, actually showing the CH3 on the left bond is not necessary. - (HS Chem Teacher)

I think that the picture still needs to be changed though, as it is misleading for these reasons:

• The hydrogen atom does not ionize by itself unless it is in an appropriate solvent, say, water. This should be indicated somewhere, perhaps this reaction with the solvent should be drawn explicitly in the diagram.
• The diagram depicts the resonace incorrectly - the negative charge does not reside on the carbon atom - rather it is "shared" between the two oxygen atoms. Either we draw an extra resonance diagram where it clearly shows how the charge bounces around the two oxygen atoms (along with the push arrows) or we enclose the whole ionized molecule in square brackets, and indicate a negative charge on the outside of it, like [CH3COO]- . What are your thoughts? HappyCamper 04:13, 28 Mar 2005 (UTC)

Personally I'd rather omit the resonance structure entirely since dissociation is a phenomenon of the acid dissolved in water, and does not occur to any real extent in the pure substance. We don't write the equilibrium H₂O ←→ OH^- + H⁺ for the picture of water on account of the one part in 10^-7 that is dissociated at pH 7. Shimmin 11:55, Mar 28, 2005 (UTC)

Quite true, the resonance is only required provided that the dissociation occurs, and there is no reason why we should assume that the molecule is in water anyway. It could be in, say, methanol! In that case, I think we should just settle for the typical picture of acetic acid, without the dissociation illustrated. HappyCamper 14:04, 28 Mar 2005 (UTC)

Acetic acid's solubility

Is acetic acid lipid(oil) soluble? If yes, is the partition oil/water coefficient known?

• this depends very strongly on the identity of the oil.

GILLIGANS ISLAND... the actual formula for acetic acid is much deeper then it seems. wen crossing over the binary compunds must use the valence number of the electronegative side.

Name

As the official name for the acid is now Ethanoic acid, shouldn't we change everything around to reflect this? i.e. change the main article to ethanoic acid and make acetic acid a redirect, and change all the references around?

• No (sarcasm) chemist calls it "Ethanoic Acid" outside of the intro organic chemistry lecture hall.

• • I haven't heard it called "ethanoic acid" even in the lecture hall. Our naming convention (Use the most common name of a person or thing that does not conflict with the names of other people or things) is to use the name that is commonly used, over the name that (even a well-respected governing body) feels should be commonly used. Shimmin 22:17, Dec 13, 2004 (UTC)

• That's not true - I haven't heard it called acetic acid for years. The substance is ethanoic acid. That's its name. I agree with the original poster. Match March 4, 2005

I have never called it acetic acid. It is not something that one comes across in everyday use such as water, and therefore the systematic name that one learns at school (ethanoic acid) tends to stick. However I agree that acetic is probably still more common than ethanoic; I went to school in the 1990s and probably older generations did not use ethanoic to the same extent. Booshank (talk) 13:54, 2 February 2009 (UTC)

From the preamble to IUPAC's 1993 nomenclature recommendations:

In contrast to such systematic names, there are traditional names, semisystematic or trivial, which are widely used for a core group of common compounds. Examples are "acetic acid", "benzene", "cholesterol", "styrene", "formaldehyde", "water", "iron". Many of these names are also part of general nonscientific language and are thus not confined to use within the science of chemistry. They are useful, and in many cases indispensable (consider the alternative systematic name for cholesterol, for example). Little is to be gained, and certainly much to be lost, by replacing such names. Therefore, where they meet the requirements of utility and precision, and can be expected to continue to be widely used by chemists and others, they are retained and, for the most part, preferred in this Guide.

When the governing body that recommends a system of nomenclature acknowledges that for some compounds, their systematic name has failed to displace, and insofar as the future is forseeable will continue to fail to displace, the traditional name, and is OK with that, it seems foolish to promote that system of nomenclature more zealously than the governing body itself. Shimmin 14:56, Mar 4, 2005 (UTC)

• • That's fair enough - I've always been taught ethanoic acid over acetic and have been told off by chemistry teachers for using it, so from my experience the point was valid. I still think we should switch to ethanoic acid but never mind. Match

If you follow the link to IUPAC nomenclature it mentions eth- as the valid prefix and not ace-. I have always been taught ethanoic acid.

Ethanoic acid is the systematic name. What the excerpt quoted from the IUPAC guide above says, however, is that for some substances, there exists a deeply entrenched non-systematic name that the systematic name has mostly failed to displace, and that in such cases, IUPAC does not insist that the systematic name be used. It specifically mentions acetic acid as an example of such a substance. Shimmin 11:24, 3 July 2006 (UTC)

The dissociation structure with the delocalized negative charge should have a minus sign written in to demonstrate the conservation of charge.

Do we want to include dimeric acetic acid (hydrogen-bonded) since acetic acid is dimeric in soluo?

Grand

Such a grand article on such a grand subject. Acetic'^Acid 14:36, September 1, 2005 (UTC)

Peer review of this article

It took me a while to find this so I'm adding the link here- this article is undergoing peer review at this location, in preparation for it becoming a featured article. Please add your constructive criticism. Walkerma 21:01, 3 October 2005 (UTC)

• For future reference, Martin, the link is always included in the big header on top of the talk page indicating that the article in on peer review. Wim van Dorst 21:07, 14 October 2005 (UTC).

Production figures

Thanks to the editor who corrected the production figures: 5 Mt/a seems more plausible than the 2 Mt/a quoted in Chem. Eng. News. Physchim62 21:05, 3 October 2005 (UTC)

• You're welcome. Although it was previously indicated 'over 2 Mt/a', the (probably?) US figure alone was indeed misleading. I also have good data now on Uses. If only I had 30 hours in a day. Wim van Dorst 19:51, 4 October 2005 (UTC).

Abbreviation

We're close to a revert war over the question of the correct abbreviation for acetic acid! Some say AcOH, others say HAc. My preference is for AcOH, based on the following IUPAC source: Ac is the abbreviation for acetyl not acetate. Physchim62 08:38, 15 October 2005 (UTC) (ducks to avoid opposing fire...)

AcH is a common abbreviation for acetaldehyde. Those wishing to convince themselves of this may google for '"acetic acid" AcH' and find that the first several hits all use the abbreviation AcH for acetaldehyde rather than acetic acid. Shimmin 12:03, 15 October 2005 (UTC)

• HAc is, in my humble opinion, the common abbreviation for acetic acid (suggesting hydrogen acetate). The Ac abbreviation for this is even noted on the acetate wikipage, whereas no such abbreviation is mentioned on the acetyl page. HAc notation is also in line with the inorganic terminology for monoprotic acids, such as HCl, and HNO₃. The AcOH abbreviation in the this context wrongly suggests an alkaline instead of acidic behaviour.
  • (checks q:Karl von Clausewitz...) the abbreviation is mentioned on Acetyl, and Acetate has a {{disputed}} notice on it! Physchim62 18:12, 15 October 2005 (UTC)
• And it does happen that my personal experience is in line with the HAc as the common abbreviation (and never used/seen AcOH for this purpose).
• The ref of PC is about ligands only. I admit that for indicating the Acetyl as ligand in an organic structure, there is no acetate ligand, hence no abbreviation for it. But the text HAc is here about an abbreviation for the whole compound, to indicate its acidic nature.
• The AcH is not in question here, whether it indicates another chemical or not.
• :-) shooting while ducking, and rolling like 007 behind a wall to wart off flaming rebuttal, albeit not afraid a some firm standpoint. Wim van Dorst 17:48, 15 October 2005 (UTC)

After PC's stab here (just kidding, PC), I can only follow the Dalai Lama and practise compassion: how about adding both abbreviations to the text? Wim van Dorst.

• Done! That saves us having to buy Martin a Blue Helmet! Physchim62 20:05, 15 October 2005 (UTC)

I have an Organic chemistry M.S. degree. My experience among organic chemists is Ac stands for acetyl group (CH₃CO-) and OAc (or AcO) is for an acetate group (CH₃COO-); the acetate ion (CH₃COO^-) is abbreviated as OAc^- or AcO^- ; acetic acid is HOAc or AcOH. Although I've seen a couple of analytical/inorganic chemists use HAc for acetic acid and Ac^- for acetate, organic chemists I've seen remark on this tend to regard such guys with a bit of skepticism as if they don't pay attention to the fine detail of doing things correctly.
H Padleckas 00:14, 3 November 2005 (UTC)

Maybe we should mention it both ways. :-/ H Padleckas 00:34, 3 November 2005 (UTC)

• We do, don't we? That has been decided 15 october Wim van Dorst 01:18, 3 November 2005 (UTC).

Dialects

On Sept. 25, 2005, User:Wayward did an edit that changed an article written with U.S. spellings to one written with British spellings. My impression was that this sort of thing was frowned upon. Shimmin 12:07, 15 October 2005 (UTC)

The diff is here. What is worse is that there may be some spelling mistakes, as not all spellings in -ise are acceptable in British English! I would assume WP:FAITH, as the same user has also edited articles British → U.S., e.g. White gold: maybe they were just trying to have a consistent spelling throughout the article (which is WikiPolicy). You can always ask at the talk page or vote on the request for adminship... Physchim62 12:35, 15 October 2005 (UTC)

My preference is decidedly for consistency. So would any of the native English speakers be so kind to comb the articles for erroneous -ize/-ise and -our/-or variations, and improve the text to the requested high standard? (PS. I saw the change, and did frown upon it. I hesitantly accepted it for a consistency improvement beyond my expertise). Wim van Dorst 17:53, 15 October 2005 (UTC).

By the time I did a final copy-edit, the article was almost entirely in British English (I found one "vapor" to change to "vapour"). Physchim62 (talk·RfA) 08:59, 4 November 2005 (UTC)

As you suspected, User:Wayward did indeed make the spelling more "British" than even current British practice. OED prefers dimerize, crystallize, civilization, commercialize, oxidize, polymerize, and utilize, but also catalyse and practise. OED prefers odour, colour and vapour, but also malodorous. Shimmin 17:47, 6 November 2005 (UTC)

Semi-Related

I just figured you should check this out, considering the article name. Karmafist 21:57, 25 October 2005 (UTC)

Comments for footnotes

Text moved from the article proper:

How to add a footnote:

  NOTE: Footnotes in this article use names, not numbers. Please see Wikipedia:Footnotes for details.
    1) Assign your footnote a unique name, for example TheSun_Dec9. 
    2) Add the macro [1] to the body of the article, where you want the new footnote.
    3) Take note of the name of the footnote that immediately precedes yours in the article body. 
    4) Add #^  to the list, immediately below the footnote you noted in step 3.  No need to re-number anything!
    5) Multiple footnotes to the same reference: see Wikipedia:Footnotes for a how-to.
  NOTE: It is important to add footnotes in the right order in the list!

I moved this text out of the article as it would there only add dead weight, which I think is not the way to do it. Wim van Dorst 20:20, 26 October 2005 (UTC)

Use in dye

Martin, it wasn't an error in your text that said that acetic acid was used as a solvent in the manufacture of indigo dye: it was an intentional addition by me to adjust your statement in the first place. Actually, I can't find any corroboration that either acetic acid, or more lower in the text monochloroacetic acid (MCA), is used in the production of indigo dye, not as raw material nor as solvent. Could you please check your reference about this? If the application is (was?) really as large as you indicate, I would have expected to have read about it in my CEH documentation, even if it were merely as a solvent. Wim van Dorst 22:41, 2 November 2005 (UTC).

I suspect that the 3000 tons of HOAc were chlorinated to MCA then converted to indigo. The BASF synthesis (1897) goes phthalimide + NaOCl gives anthranilic acid. Anthranilic acid + MCA gives HOOC-C6H4-NH-CH2COOH, which upon treatment with alkali gives indoxyl. In air indoxyl forms indigo blue. The improved Hoechst process (1901) goes aniline + MCA gives phenylglycine, which is treated with NaOH then NaNH2 to give indoxyl. I was planning on writing this synthesis up as part of the support material for the acetic acid article anyway. What do your sources give as the synthesis of indigo?

The Martin book is 1917. I have Perkins "Organic Chemistry" from 1922 in my lap, and it states three uses, "(Anhydrous) acetic acid is largely used in chemistry laboratories, and in the manufacture of organic dyes (my emphasis), as well as for the preparation of many acetates...(meaning metal acetates). In 1922/1917 there was no PVA or PET, but indigo was big business - and glacial acetic acid was not such a major commodity then.

I located my more modern source on indigo, Wittcoff & Reuben, Industrial Organic Chemicals in Perspective, Part 2, p450-451, Wiley, 1980. It mentions the $2 million invested in 1897 by BASF to develop their process, "an enormous sum for those days." That implies that synthetic indigo was an important product at that time. The book states that the Hoechst process is "still in use," and since the book is mainly focussed on current production, not history, that carries the implication that the Hoechst sodamide process was the main process used in 1980. Unfortunately this book is poor at describing the uses of acetic acid itself. I will post more info here tomorrow when I'm at work and can consult other books. Walkerma 03:35, 3 November 2005 (UTC)

UPDATE. In Tedder, Nechvatal & Jubb, Basic Organic Chemistry, Part 5: Industrial products, Wiley, 1975, page 65 it lists the end uses of acetic acid ("in the USA in 1970") as follows – Cellulose acetate 44%, Vinyl acetate monomer 31%, Solvent esters 14%, Chloroacetic acid 3% (my emphasis), Others 8%. Since your company makes chloroacetic acid, can you find what it is used for these days? Based on Wittcoff & Reuben I'd guess that in 1970 some of that went into making indigo. I've also worked a little with chloroacetyl chloride in the synthesis of a major drug intermediate, I suspect pharma is a major end use these days.

A final (hopefully) review observation

Overall: Outstanding, although just a trifle long. I restrained myself from adding more material than I did. In addition to my above remark on HOAc and HAc:

In the following chemical reaction images, the reviewing chemists know what the reactants and products are from their structures, but this may not be obvious to the average non-technical reader trying to learn about these things. I'm thinking of modifying the images to add some labels below some of the most important products in the reactions and then re-uploading the images back onto Wikimedia.

• Deprotonation of acetic acid equilibrium in water

• Two typical oganic reactions of acetic acid

• Condensation of acetic acid to actetic anhydride

H Padleckas 01:19, 3 November 2005 (UTC)

This can rather easily be fixed. Let's go on to FAC. H Padleckas 01:21, 3 November 2005 (UTC)

There it goes: FAC now!

Wim van Dorst 19:55, 3 November 2005 (UTC). And FA. Wim van Dorst 14:43, 13 November 2005 (UTC).

Picture locations

On screens wide enough to bring the frozen acetic acid pictures up against the bottom of the infobox, the new picture locations produce an undesirable gap in the text. Was there some equally undesirable phenomonon occurring in their old location? Shimmin 17:04, 4 November 2005 (UTC)

On my (laptop, so small) screen the page looks much better since the move, because the text is not so broken up. Is this the problem you mention likely to be common or not? Walkerma 02:28, 7 November 2005 (UTC)

The two pictures of frozen acetic acid are put before the history section paragraph beginning "In the Rennaissance..." At 1024 px, or narrower if the font is small, the infobox is still taking up the right side of the page at this point in the text, but the pictures of glacial acetic acid also request to be on the right side of the page.

The source of the problem is that we have a lot of things that want to be at the right-hand side of the screen, and if the the font is small or the screen is wide, the point in the text where they appear is reached before the right side is clear, and so either the text or the images appear in a suboptimal location.

IE handles the problem by moving the text, opening up a blank space in the text, so that this paragraph is pushed below the bottom of the infobox, but the associated images do appear to the right of the paragraph. Firefox moves the images instead, and the text appears uninterrupted, but not next to the images. This isn't so much a problem with these images, since the text doesn't really need them at any given point, but would be a problem if the images were actually relevant to the history text.

If I use a smaller font, (and presumably also if I had a screen wider than 1024 px), the cyclic dimer and chemical reactions images are similarly pushed away from their associated text in Firefox, or gaps open up in IE. Shimmin 15:25, 7 November 2005 (UTC)

• Indeed everybody with a relatively wide (1024 wide?? I'm at 1920 now) screen have these uncouth text breaks and oddly moving pictures. I took the liberty to revert some picture movals, essentially moving two back to where PC put them in the first place. This solves on narrow screens (actually wide with very large letters) and on wide screens (tiny font on 1920px) the odd effects. Martin, can you live with this? Wim van Dorst 20:37, 7 November 2005 (UTC).

Looks just fine on my little laptop screen! Walkerma 21:01, 7 November 2005 (UTC)

Related chemicals vs related compounds duplication

I notice we now have a "related chemicals" section which duplicates our more usual "related compounds" section that we have on our standard chembox. Do we want to have this info twice? Or should we stick with our standard format? Walkerma 02:38, 7 November 2005 (UTC)

The See also section is meant as a quick jumper to related articles. It is a standardized format throughout the Wikipedia project and it is the first place where people look for related articles. All links from the new See also section can be found in the text and are therefore intentionally duplicated. There is no guideline against this practice and it increases usability. A clear keep for all mentioned lists. Cacycle 11:02, 7 November 2005 (UTC)

OK, let's leave it, I agree it increases usability. I just thought I'd better ask the question. Walkerma 20:18, 10 November 2005 (UTC)

Spectroscopic information

Is it possible to add spectroscopic information about acetic acid to this article, or would that be going a bit overboard? --HappyCamper 18:46, 12 November 2005 (UTC)

Feel free to add it to Acetic acid (data page). Shimmin 19:40, 12 November 2005 (UTC)

I have put in IR, MS, 1H and 13C NMR spectral info into the supp. table, using the SDBS spectral database. Does anyone have access to decent UV data? NIST is poor on this compound. Thanks for pointing out this problem, HappyCamper. Walkerma 07:22, 13 November 2005 (UTC)

λ_max = 207 nm in the gas phase: Orlando, John J.; Tyndall, Geoffrey S. (2003). "Gas phase UV absorption spectra for peracetic acid, and for acetic acid monomers and dimers." J. Photochem. Photobiol. A: Chem. 157, 161–66. Physchim62 (talk) 12:24, 13 November 2005 (UTC)

Wonderful!! I love this article :-) --HappyCamper 02:19, 19 November 2005 (UTC)

Is 'a' the best abbreviation for year as in 'Mt/a'?

Please see discussion on this at Wikipedia_talk:Manual_of_Style: Is 'a' the best abbreviation for year as in 'Mt/a'?. Bobblewik 23:07, 23 November 2005 (UTC)

EU HazMat classification

Sorry, I goofed on the link I tried to put in my recent edit comment. According to Directive_67/548/EEC#Classification_of_dangerous_substances, there is a C-Corrosive classification, but neither that nor any of the others classifications appear to mention acidic. Therefore I reverted the recent and anonymous addition of "and acidic" to the corrosive classification in the infobox. I mention it here to catch the eye of any experts who may know better – I'm not one of you. -- Kbh3rd 18:23, 2 December 2005 (UTC)

I'm pretty sure you're right, though User:Physchim62 is our expert on this topic. I think the edit was well-intentioned, but "acidic" is not a standard EU term. Walkerma 19:09, 2 December 2005 (UTC)

No, the official term is Corrosive, which covers both acids and alkalis, or specifically those preparations whose pH is ≤2 or ≥11.5. The classification is associated with the R-Phrase {{R35}} if skin damage occurs in less than three minutes, or with {{R34}} if the skin damage occurs in less than four hours. Official EU classifications may be found on the site of the European Chemicals Bureau (which is one reason why we use them, they're easily accessible and verifiable). Physchim62 (talk) 11:39, 3 December 2005 (UTC)

congratulations!

My congratulations to all the people who have contributed to acetic acid, todays featured article V8rik 20:15, 2 December 2005 (UTC)

• Thanks, It resulted in well over 200 edits, effectively adding just a few °F entries and some small text edits. Only one was IMHO an improvement: a spelling error correction. Wim van Dorst 20:30, 3 December 2005 (UTC).

"Use as solvent" link

I noticed that the link for "above" in the first line of the "Use as solvent" subsection does not seem to work. I assume this should redirect to the Solvent subsection under "Chemical Properties". Does anyone know how to make this work? A couple of possible solutions:

• Increase the level (I don't know if "level" is the right word) of the headings under Chemical Properties (e.g. like the level of subsection headings for the Applications section)
• Redirect to the chemical properties section instead

--GregRM 21:52, 18 December 2005 (UTC)

Thanks. During the peer review someone downgraded the section headings to bold text, and this link was lost. I've done what you suggest, it now links to chem properties. Walkerma 06:16, 19 December 2005 (UTC)

Vinyl acetate monomer reaction

The recent edits to the vinyl acetate monomer section brought my attention to the balancing of the reaction. Is hydrogen gas produced as well? If so, perhaps this should be included in the reaction equation.--GregRM 17:48, 20 December 2005 (UTC)

I've balanced it now. It was done in an "organic chem" style, we often don't balance equations, but the missing oxygen rendered that very confusing! It's based on the Wacker process (see Acetic_acid#Ethylene_oxidation), it will form acetaldehyde. This has an enol form (vinyl alcohol) which can then form its ester, vinyl acetate; or it may well go directly to the ester, I'm not sure. Thanks, Walkerma 18:10, 20 December 2005 (UTC)

Most widely produced?

The section "Production" contains the claim This makes it [acetic acid] the most widely produced acid in the world. Does it mean, produced in the most locations? If so that is probably true but only if we include non-synthetic(vinegar) production, whilst ignoring non-synthetic production of of other acids. In any case one would ordinarily understand it to mean that acetic acid has the greatest industrial/commercial tonnage produced annually. However, that isn't even close; at least sulphuric, nitric and hydrochloric acids have an order of magnitude greater production. Possibly it was meant that it is the most widely produced organic acid, but I don't know if that is the case so for the moment I'm removing it. -- Securiger 03:36, 1 June 2006 (UTC)

Thanks for spotting that. It wasn't in the article when it was made a featured article. Walkerma 05:09, 1 June 2006 (UTC)

fats

I was wondering how can it be a fatty acid if it is not found in any natural lipids.

Onion mention.

See [2], Betsy Anderson, Production Assistant comment. --Neutrality^talk 17:29, 27 August 2006 (UTC)

Formula??

I've also seen the formula as CH₃C(O)OH. Which is correct? Ruff ^{Bark away!} 18:39, 27 October 2006 (UTC)

All are similar, your CH₃C(O)OH adds the info that the O is a side-group from the 'main chain' .. though noone would mistake CH₃COOH for a peroxide, the OOH notation is used for peroxides. --Dirk Beetstra ^{T C} 18:54, 27 October 2006 (UTC)

Chemical formula

The listed formula is given as C₂H₃O₂, which is actually the formula for the negatively charged ion acetate. The correct formula should have a hydrogen atom in front of the formula for acetate: HC₂H₃O₂—The preceding unsigned comment was added by 69.168.174.232 (talk • contribs).

Where does the incorrect formula appear? I skimmed the article and did not notice the incorrect formula you mentioned. Thanks.--GregRM 04:22, 31 December 2006 (UTC)

Like Greg, I can't see the error anywhere. The formula you mention is rarely used in my experience - I've only seen it used in cases when students have not yet learnt organic chemistry, but they need to show an acidic hydrogen. I prefer the formula as it is given in the infobox, which follows the Hill system. Walkerma 04:37, 31 December 2006 (UTC)

The problem has already been corrected. I don't have an issue with the formula given in the infobox as opposed to mine. It is probably more accurate anyway. Thank you.

Indigo and Acetic Acid

Okay, recently in my Chemistry class, we did a reaction that allows us to produce indigo dye and involved glacial acetic acid. I feel that it needs mentioning in the article under Applications, but I fear that my edits won't be up to FA quality, and I don't have any supporting sources, not yet at least. This is what I have so far:

Indigo Production

In the past century, glacial acetic acid has become important in the prouction of synthetic indigo. In 1897, the first feasible reaction on an industrial scale was perfected, allowing this once hard to obtain dye to be widely available, and is the dye used in making blue jeans their distinct color. The process involves the mixing of various chemicals, such as glacial acetic acid, o-nitrobenzaldehyde, sulfuric acid, dimethyl thionate, sodium hydroxide, and acetone in a specific and fairly complex sequence that will result in indigo, which must be converted into leucoindigo before being introduced into the fabric to be dyed, and will quickly revert back into normal indigo. This is a fairly well known reaction, and is done as a basic intro to organic compounds in high school science labs.

If I can get my hands on the sheet, I can detail the process and provide a bit of sourcing, but I think it still needs more work than that. Can you guys give me a hand here? Also, I can provide a picture of the effects of it. I have some socks I dyed with the dye I made. --RockMaster 01:55, 8 March 2007 (UTC)

I only just saw this - sorry! Indigo manufacture does get a mention (I know, I added it!) in the history section - see the final sentence. I will try to look at this after exams are over (3 weeks or so), feel free to remind me if I forget. I have some books on industrial chemistry. I don't think it warrants the level of detail you go into - but maybe a sentence could be added here. Acetic acid is such an important solvent and acid, you could find 50 other important products where it plays an important role (e.g., we do a lab at my college converting camphene to isobornyl acetate using acetic acid - part of an industrial process for making camphor from turpentine). However we should look at all the things covered here - indigo in particular, and make sure this synthesis is included, because historically it was very important. Walkerma 06:42, 2 May 2007 (UTC)

Thanks, Walkerma 06:42, 2 May 2007 (UTC)

Molecular Formula

Very small point but where it says molecular formula what is actually put is the linear formula, molecular formula contain only the number of atoms in a compound, not the arrangement. —Preceding unsigned comment added by 84.65.39.253 (talk) 19:45, 7 November 2007 (UTC)