Wikipedia:Peer review/Acetic acid/archive1

Acetic acid

This article has come out of Wikipedia:WikiProject Chemicals, where the general consensus is that it's pretty good. However, it would be useful to get some opinions from the wider community as to what Wikipedians want from an article such as this, as well as specific comments on the acetic acid article itself. Physchim62 18:34, 24 September 2005 (UTC)

• A very good article to start with. Recommendations for further improvement include
  • More information about uses
  • More or better information about commercial production
  • Info about world market size, and major producers
  • Textual improvements, spelling corrects, etc.

Of course, I'll chip in myself to do some of these. Wim van Dorst 21:37, 24 September 2005 (UTC).

The article is mostly well-written. The only problem is that the article's lead section, and especially the section on Chemical and physical properties, can get confusing. Obviously in a science article technical information will come up, but make sure every term is linked to a good article ("dimer," in particular, isn't linked) so that a layman can follow along, even if he has to click a few links to understand the terms. Think of the reader; scientists probably aren't going to need this page, but high schoolers or middle schoolers might. The infobox links to everything, which is extremely helpful; keep up that same helpfulness in the text. With just a bit more clarification for the non-expert, this could easily be a top-notch featured article.Kevin M Marshall 20:29, 25 September 2005 (UTC)

It would be helpful if you could use actual structures instead of ASCII art. Also the image of the structure in the infobox could be larger in order to scale down nicely. Otherwise I agree with the comments above. -- Rune Welsh ταλκ 11:35, 28 September 2005 (UTC)

Forgot to mention: let me know if you need help creating the structures. -- Rune Welsh ταλκ 14:39, 28 September 2005 (UTC)

• Yes, both the dimer as well as the anhydride could do with a proper structure drawing. I fully agree. Please be so kind as to contribute. And if you would happen to have a nice fotographs of glacial acetic acid crystals, that would even be better (for the chembox). Wim van Dorst 22:21, 28 September 2005 (UTC).

Got the structures, but someone else will have to get the pictures. I'm on sabbatical right now and the lab is fortunately far, far away. -- Rune Welsh ταλκ 23:05, 28 September 2005 (UTC)

I can take a pic of a huge winchester of acetic acid- and I could probably get one of the crystals if someone told me how to make them.--nixie 01:03, 29 September 2005 (UTC)

• Yes, please add a winchester to the page. That would be a welcome addition. Perhaps you can even add a short text what it is for, in the article too. And I guess that creating crystals would be easy (never done it, though): take a concentrated solution of acetic acid (glacial acetic acid) and cool it below 16.6 °C. For very nice crystals, you maye have to trick it a bit, e.g., by starting off with a non-concentrated solution and cool it really slow and long. Wim van Dorst 07:09, 29 September 2005 (UTC).

Depends where you are. In Arras the nighttime temperatures are below 16 °C, but I don't have any glacial acetic acid... Otherwise, I would leave a sealed container (eg Tupperware box) outdoors overnight and take the picture in the morning. Hazard warning: Glacial acetic acid is corrosive, and the smell of the vapour can be quite overpowering in a confined space. Wear plastic gloves and eye protection, and work in a ventilated environment (eg outdoors). Thanks for the structure, ChemSketch wouldn't let me draw hydrogen bonds. Physchim62 07:23, 29 September 2005 (UTC)

A nice picture (but it is water ice instead of acetic acid ice) as an excellent example of a picture: [1]. Probably copyrighted, so I can't include it here. Wim van Dorst 11:57, 29 September 2005 (UTC).

So if I put some glacial acetic acid in the cold room (4 degrees C) over night- in a closed shallow container- I could have crystals in the morning? If so I will set it up when I'm net in the lab.--nixie 10:50, 30 September 2005 (UTC)

• Since last, I have copy-edited the article (and still working on it), focussing on the comments above. I would appreciate renewed comments. Wim van Dorst 21:32, 2 October 2005 (UTC).

Since the comments I had made earlier were addressed, I decided to see what similar articles are FA's and to start seriously thinking about the FA potential of this article. Hydrochloric acid is an FA, and it's a good bit longer than the acetic acid article. I think the set-up of this article is very good right now, but it should probably be a bit bigger. In particular:

• The history section could probably use some information from closer to the present day (right now the last year mentioned is 1847.
• Would a table like the one at Hydrochloric acid#Physical properties be useful to show the differences between varying concentrations of acetic acid?
• The Biochemistry section is extremely short. What more can be said?
• The chemical and physical properties section could probably be lengthened a bit if more information from the links is brought into the article. Hydrochloric acid#Chemistry mentions, for example, a few facts about monoprotic acids; perhaps the corresponding section for acetic acid could mention a few salient points about carboxyl groups.
• In short, basically every section would probably need to be a bit longer for this to be an FA.Kevin M Marshall 23:33, 2 October 2005 (UTC)

I will have a go at some pictures next Monday or Tuesday, I will post my best choices here then. Busy busy till then! Walkerma 21:04, 3 October 2005 (UTC)

Many changes have been added to the article now, making a major leap forward. I would think that nearly all comments here have been catered for. Nonetheless, I would propose to let it settle down a bit: further additions and other improvements are still welcome. Notably PICTURES!!!! Wim van Dorst 21:11, 14 October 2005 (UTC).

Agree. The applications section could do with being less note-like, and the chemistry section needs attention, but neither of these seems beyond the capacities of the WikiProject Chemicals team! For the chemistry section, we will need to decide on the split of information between acetic acid and carboxylic acid. To answer one point from Kevin M Marshall, I don't think a table of physical properties would be as interesting here as it is for hydrochloric acid: if I can dig one out, I will place it on acetic acid chemdata supplement. Physchim62 09:05, 15 October 2005 (UTC)

The article is shaping up nicely, thanks guys. A few comments: I agree that the chem needs expanding. I will try to do a couple of reaction schemes and some text to go around them. Regarding its uses, I think I would like to see more on its use as a solvent. The biochem I suspect could be bigger, but I can't help much there. In the production, I would like to add something more on the Showa Denko KK process which I think looks competitive with CATIVA, plus we need a little more on CATIVA. I accept PC's comment that we don't want simply to duplicate a full article on the Monsanto process or CATIVA. However I think the basic info should be there (I faced this recently when I rewrote sulfuric acid where I wanted to summarise the Contact process). The article should be such that someone printing off the article has the basics of all the main methods right there on the page; we can leave subtleties like by-product distributions for the more detailed articles. As for the photos, we have literally have had about 10 days of very overcast weather here, with rain on & off, preventing the taking of decent photos. (Flash gives very flat pix, see some of my early efforts). I will have a go at pictures as soon as things clear up. Walkerma 21:25, 16 October 2005 (UTC)

Solid glacial acetic acid (#1)

Solid glacial acetic acid (#7)

Solid glacial acetic acid (#10)

Solid glacial acetic acid (#11)

Solid glacial acetic acid (#12)

A couple more comments- I think the chlorination should be mentioned, it is my impression that a lot of drug syntheses use chloroacetic acid or chloroacetyl chloride. Acetic acid is also unique among carboxylic acids in that a trihalo acid can be formed; and isn't TFA pretty important in that regard? Also, as I understand it most acetic anhydride is not made from acetic acid, it is made directly by the Monsanto process by use of reduced water. If it had to be made from HOAc and P4O10 it would be much more expensive than it is. Finally, my personal feeling is that HAc is considered WRONG for acetic acid, at least in the USA (I have seen my former prof shout at people for this!). Ac is an ACS approved abbreviation (see issue 1 of any year of JOC, near the beginning), and as such HAc would mean acetaldehyde. Walkerma 21:39, 16 October 2005 (UTC)

Just saw the debate on the HOAc talk page. I wonder if this is an academic/industrial thing (like the meaning of EDC)? HOAc is the common abbreviation I see, but I can accept Wim's comment as true. I back down on that. Walkerma 21:46, 16 October 2005 (UTC)

I agree with Martin that the chem section is still too poor: I suggest we work on this in parallel with carboxylic acid. Yes, chlorination must be mentioned. Some acetic anhydride is made by direct gas-phase dehydration of acetic acid (no, I don't know how the raction works, but I will try to figure it out, probably with a ketene intermediate). As for biochemistry, we could probably do with a description of how the levels of free acetic acid are kept so low. Martin, if you mail me the Showa Denko paper I will try to see what the catch is ('cos there probably is one...).

Given the debate on Talk:Acetic acid, we cannot really pretend that HAc is not used as an abbreviation for acetic acid, and so it ought to be mentioned in the article. Physchim62 07:45, 17 October 2005 (UTC)

• I have been looking into the chlorination reaction: the mono/di/trichloro-acetic acids are already mentioned under the 'Other applications' sections. Sorry to say, but this is all it is worth, IMHO: the chlorination is just a boring reaction and has nothing special with it acting on acetic acid. So, I don't think is needs explicit mentioning in the Chemistry-section. And the amount of MCA/DCA/TCA being produced from acetic is also minor, so I don't think the chlorination should get more prominence.
• The acetic acid used in TFA production is as a solvent, as it is used elsewhere. I agree that acetic acid's solvency power should be mentioned in the chemistry section.
• Some additional info from the Monsanto and the Cativa processes has been added to the related section. For me, I think this shows enough detail in this acetic acid article. More details should be added to the pertaining wikipages. Notably the Cativa process needs more details: it's a mere stub.
• That a lot of acetic anhydride is made from other raw material than acetic acid (as Martin says) isn't relevant to the acetic acid article: given that upto 30% of all acetic acid is used for the production of acetic anhydride is a good reason IMHO to give it the prominent place it currently has. And I understand that the formation of anhydride is typical for carboxylic acids, so to have the condensation reaction in the chemistry section is acceptable.
• Actually, I think the article quite good as it is. Wim van Dorst 21:10, 18 October 2005 (UTC).

I think acetic anhydride prepn at "Monsanto process" plants is the cheapest way to make it, and this is relevant because they it is being made at an acetic acid plant. The flexibility of that process that allows a plant to make the acid one week, the anhydride the next, is probably a big factor in affecting the viability of carbonylations over other methods. I read somewhere recently that all the major carbonylation plants can do either/or. If 30% is made by older methods (I realise P4O10 has never been used, but ketene has), then definitely this needs a big place. BTW, a major use for chloroacetic acid is in making dyes, mainly indigo (unless there's a new method for indigo I'm unaware of), and one source I read suggests that 2% of acetic acid is used for this, though it may be out of date (there are a lot of blue jeans!). Walkerma 17:25, 22 October 2005 (UTC)

Correct me if I'm wrong, Martin, but isn't chloroacetic acid prepared by the oxidative hydration of vinyl chloride? Free radical chlorination produces a mix of the three, unless you leave it long enough to have fairly pure trichloroacetic acid. Physchim62 17:29, 22 October 2005 (UTC)

I can tell you that we (Akzo Nobel, chlor-alkali related business units) are a monochloroacetic acid (MCA) producer with the following:

• production process is 'simple' chlorination of acetic acid. By-product is hydrochloric acid, being recycled into the hydrochloric acid business. And the di- and tri- production are kept at bay with good catalysts (iirc).
• indigo is not being produced from chloroacetic acid, says indigo dye
• our MCA is not being used for indigo, but other applications. If we can show the reaction mechanism to from acetic acid to indigo, perhaps it should be listed in the indigo dye article. But merely 2% means it is just one of the minor applications, where it is currently actually listed.

So all in all, even as an chloroacetic acid producer myself, I retain that MCA/DCA/TCA have all the floodlight in the current acetic acid article that they should have. Wim van Dorst 20:22, 22 October 2005 (UTC).

Pictures

Glacial acetic acid, cut-out of Nr 10

I have uploaded some of the better pictures we took yesterday, thumbnails of 1, 7, 10, 11, 12 are shown in order on the right. Regarding the chemical composition, I should mention that the beaker was placed in a freezer for about 6 hours with a cover of Al foil. This is not watertight, though it shouldn't have picked up a huge amount of water, also the general humidity here is quite low now. I do not believe that the crystals contain much H2O because of the fact that even the delicate crystals remained frozen for about 15 minutes in direct sunshine. I think the crystals formed when the acetic acid vapour was cooled very quickly. Please vote on your favourites! Walkerma 17:25, 22 October 2005 (UTC)

• Nice pictures, Martin. Any chance of putting some crystals out of the beaker onto a black or darkblue background and then take a picture. Preferably close up? In that way, you could make a dazzling glorious picture, that could be used on top of the chembox, and for the wikipedia homepage, assuming we get that far (stretchgoal? Nah, that is the real goal). Wim van Dorst 20:36, 22 October 2005 (UTC). ps. I like nr 10 best, sofar.

• • n° 10 is good, but I like n° 12 as well. Physchim62 21:08, 22 October 2005 (UTC)

• • #12 is my favorite of these. ‣ᓛᖁᑐ 04:28, 23 October 2005 (UTC)

Good illustratory material ought to be put to use, so I used picture 12 as is in the acetic acid article. Using nr 10, I made a close-up cut-out of Nr 10, to show that glacial acetic acid can be something dazzling, and not boring-stuff-in-picture. Shall we use this (or similar)? And sincere thanks to David Gingrich!!. Wim van Dorst 12:19, 23 October 2005 (UTC).

Potsdam, NY had two days of sunny (but cold) weather, but now we're set for yet another week of cold, rainy, dark weather, so any new pictures are some time off. I'll try it when I can. My wife's camera is 2 MP and doesn't do good closeups, not sure about David's. I really like your close-up cutout, thanks! Walkerma 00:08, 24 October 2005 (UTC)

Update: I was unable to get pictures of HOAc crystals on a dark background today, they melted before I could take the picture. I think we'll have to go with the pictures we have, and I think Wim's close-up looks pretty enough anyway. Walkerma 19:42, 30 October 2005 (UTC)

Structure for chembox

Line-angle representation of acetic acid

Chemical structure of acetic acid #1

Chemical structure of acetic acid #2

I agree that it is reasonable for the chembox for acetic acid to have a structure rather than the pretty picture - it may not look as nice, but it is more informative. However the structure currently there (shown left) is a line-angle representation that would be incomprehensible to most users. I teach 2nd year science majors at a US college, and when they begin most are completely lost by line-angle formulae - and many of our users for a page like this will be kids taking a science class, or non-scientist adults. I think a Lewis structure or similar is more appropriate, and a 3D ball & stick representation looks good too. I have put up a couple of versions, please leave your comments here. Alternatively, please feel free to make your own! Walkerma 16:43, 25 October 2005 (UTC)

I like the approach taken in Benzene, where four different diagrams are shown side by side. Do we happen to have a space-filling model of acetic acid? ‣ᓛᖁᑐ 19:07, 25 October 2005 (UTC)

I don't think we have a space-filling model: these pics come from German Wikipedia, and they are only in black and white, which might explain why we only have them for hydrocarbons. Incidentally, I prefer the two pics which the Germans use to illustrate their chembox. Physchim62 19:47, 29 October 2005 (UTC)

Benzene

The benzene-approach isn't wrong either, but the clean fresh looks of the current line/angle are VERY appealing. I like that a lot, even though it means that the pretty picture has been relegated to somewhere down in the article. And I do like what Cacycle did to the other formulae and the pictures (two next to eachother) too: Well done, Cacycle. Wim van Dorst 19:23, 25 October 2005 (UTC).

Martin, like this?

Combined pictures

Met vriendelijke groeten, Wim van Dorst 16:26, 28 October 2005 (UTC).

Yes, Wim, I'd be happy with that, thank you! However I want to make sure we get the very best choice; something everyone will like, not just be able to live with! I think it may be that Cacycle's images like on the benzene page would satisfy everyone- they are like Wim's latest version, but with the spacefilling image instead of ball & stick. I don't have ChemDraw here, I will try that option. By the way, PC, the spacefilling images are not German, and not B&W, there are dozens of them produced by Cacycle, all in the same general style. See the indole picture for an example with nitrogen, benzofuran has oxygen. I don't have ChemDraw here, I'll see tomorrow if I can do this. Also, PC, my #2 above uses the picture from the German page, but I think their line structure is more crude than mine! Walkerma 02:39, 30 October 2005 (UTC)

Chemical structure of acetic acid #3

OK everyone, I managed to remember how to do the space-filling model in ChemDraw, is this representation (#3, on the left) OK? It's along the lines of the benzene one, set up like Wim's last one. I put it into the acetic acid page so we can see how it looks. I don't have a strong preference at this point, if people prefer the previous one we can revert. Thanks for your patient indulgence of my pickyness. Walkerma 16:11, 30 October 2005 (UTC)

I can live with that, the third image is much better than the ones before. I still can't figure out why you want to include the O–H bond in the line angle formula though! Physchim62 (talk·RfA) 16:15, 30 October 2005 (UTC)

I just followed what Cacycle did originally with the line-angle one, but now you point it out, I would have expected simple OH. Let me know if you need it changed. Walkerma 16:28, 30 October 2005 (UTC)

I would prefer it changed, yes. If we're using line angle formulae, let's at least show them as they're written in real life! (OK, a bit neater perhaps :) Physchim62 (talk·RfA) 16:35, 30 October 2005 (UTC)

Neat, ChemDraw seems like a nice program. I'm noticing it hasn't used many colors for the gradients in the ball-and-stick or space-filling models, though; does it have a limited color depth? ‣ᓛᖁᑐ 16:31, 30 October 2005 (UTC)

Change made as requested, I just used the same filename at Commons (so you may have to refresh your browser). I've tried to get better color depth- it looks great as a cdx (ChemDraw) file, but once you export it to TIFF, PNG etc you get those unsightly bands. Cacycle or H Padleckas may know how to avoid that, but I don't. Thanks for prompt feedback. Walkerma 17:30, 30 October 2005 (UTC)

Chemical structure of acetic acid #4

• Putting in my two (euro)cents: Martin's line/angle drawing with OH instead of O-H is much better. The 3D model however is less than the ball and stick: the other examples that you mention are flat molecules, and for those it is good, but for acetic acid (with twist) it is a rather obscure one. And with a high-resolution screen as I have, the electrons of the third picture don't show up any more (they do in my third picture). Conclusion (if we won't go for Martin's slick line/angle drawing alone), a combination of Martin's first with my second and third. Wim van Dorst 20:19, 30 October 2005 (UTC).

Wim's suggestion is now posted here as version #4. I have also cleaned up #3 in ways I think Wim would like- I brought out the lone pairs, and I rotated the methyl so you can see all three Hs better. Can we now have a vote? My judgement of these things is poor at the best of times, and my brain is fried now anyway, and I am happy with either so I will abstain. Walkerma 20:58, 30 October 2005 (UTC)

Either will be fine with me as well. ‣ᓛᖁᑐ 22:55, 30 October 2005 (UTC)

In favour of image #3 vote here:

In favour of image #4 vote here: Wim van Dorst, Physchim62 (talk·RfA) (though happy with either)

Other images, state your preference here:

I have amended the image to #4. Unless there is a sudden large group of votes otherwise, I'll assume that we are finally agreed. Why are we chemists so picky? Thanks a lot, everyone, Walkerma 03:03, 31 October 2005 (UTC)

Trimming the article a little

Henry has made the comment here that the article is "just a trifle long". I don't want this to stop us sending it in as a FAC, because I think the occasional trim is not a problem. My feeling is that the following sections could be made shorter, because their space is out of proportion with their (low) importance. Before I (or others, please?) start hacking away, what do others say? Any other things to trim?

1. Acetaldehyde oxidation- important 50 years ago, but does it need so much detail in 2005? (OK, I know I wrote a bit of it!).
2. Fermentation processes. I realise non-chemists will more interested in this than in Cativa, but we have an awful lot. I think the aerobic process is fine because of its importance for vinegar, but the anaerobic is a curiosity & should be trimmed back a bit (even though it is interesting!).
3. Nomenclature. Too late, I just edited it. The paragraph on HOAc/HAc looked like it was written by a committee (it was!) - I rewrote it so that now even I can follow it!

Otherwise I think it's now a great article. I vote for it to go to FAC. Walkerma 04:14, 3 November 2005 (UTC)

I think the latest edits to the nomenclature section at about 04:00 on November 3, 2005 by Walkerma are about as good as anything we will be able to come up with. I say we go with that. I'm glad the two sentences on acetate being an anion, salt, or ester were retained for the edification of the general public. I'm also glad the sentence saying the acidic H+ comes from the carboxyl group (not the methyl) was retained for the general public. At first to shorten the article, I was thinking of tranferring some information to a new article such as Production of acetic acid and leaving behind shorter summaries and links. I'm sure things like this have been done many times before in Wikipedia. To some extent, that may ruin the Feature Article quality of Acetic acid. The reason I was concerned about the length of the article was because it was 33 kB at the finish of my edits, which is slightly longer than the ideal maximum of 30 kB per article. However, this is by no means a terrible flaw. There have been Feature Articles larger than 30 kB before. I think we can leave it the way it is and see what the FA committee says. There is one place where two similar example esterification reactions are shown. That can be reduced to one reaction by replacing the two different alkyl groups by the general R. From just a general point of view, I don't think the article is too long. I just finished labeling the 3 images I mentioned before. I will start re-uploading them shortly. H Padleckas 05:39, 3 November 2005 (UTC)H Padleckas 05:46, 3 November 2005 (UTC)

In my last edit up till this time, I replaced the two sample esterification reactions with one generalized reaction with an R group, as I just proposed above. Then the article went into FAC status. Hooray for all of us who wrote, edited, and reviewed Acetic acid. H Padleckas 22:48, 3 November 2005 (UTC)