Wikipedia:Featured article candidates/Acid dissociation constant/archive2

Acid dissociation constant

Nominator(s): Petergans

previous FAC (23:04, 25 October 2008)

• Featured article candidates/Acid dissociation constant/archive1
• Featured article candidates/Acid dissociation constant/archive2

The article has been extensively revised in the light of FAC-type comments and I believe that it now conforms to WP:MOS. There has been much discussion regarding references. The current text follows Wikipedia:Scientific citation guidelines.

The content of this article is mostly “”common knowledge”, that is, it can be found in a wide variety of text-books on physical, inorganic, organic and analytical chemistry.. Whereas no one text-book covers all the subject matter, the advantage of WP is that it is not tied a specific teaching program and can provide broader coverage. The fact that a number of text-books are cited provides the general basis for verifiability and reduces the need to support every single paragraph with a citation. The items in acid dissociation constant#further reading provide additional verifiability support. Note also that I follow the normal procedure in chemistry, of placing the reference number close to the item being referenced, whenever it would be ambiguous as to what is being referenced if that reference were placed at the end of the sentence or paragraph. Petergans (talk) 09:49, 19 November 2008 (UTC)

• Support. I supported the previous nomination already, and now the article is even better, so there's not much else I can say. --Itub (talk) 10:06, 19 November 2008 (UTC)

• Support. I spent some time after the last FAC trying to identify MOS issues with the article, and everything I could find has been fixed. I also went through the content from the point of view of a layman with a moderately technical background; everything I found that needed clarification has been improved upon or expanded. The article now meets FAC standards and I am happy to support. Mike Christie (talk) 10:53, 19 November 2008 (UTC)

• I'm not sure how to deal with the MoS requirement to avoid special characters in section headings: I left a query at Wikipedia talk:Accessibility#ACCESS check. SandyGeorgia (Talk) 18:52, 19 November 2008 (UTC)

Oppose. Although accurate and comprehensive, this technical article would be less of a chore to read if some attention was paid to the prose. Throughout the article complicated phrases are used to express relatively simple thoughts. Here are some examples:

• "For a quantitative understanding" - does this mean "to measure"?
• "...also a prerequisite.." - how about "necessary"?
• "When operating under the assumption that.." - why not "If it is assumed" or even "Assuming that.."
• "..has a limited solubility.." - "does not dissolve well"?
• ".. with the addition of.." - "by adding"?

These are just a few random examples; there many more. There are other problems such as "it has a measurable pKa range" - so what is the unmeasurable range? Here, "all protons have been removed", have they, or are they still there but no longer free? I also noticed that Pauling's rules are linked in the body but not the Lead and I fixed one typo. I feel bad by opposing this FAC because I know the amount of blood sweat and tears that goes into these candidates, but the article does need more work. Graham Colm ^Talk 13:15, 22 November 2008 (UTC)

I see what you are getting at, but I fear that we are dealing with differences between the language used in science and in general. The phrase "quantitative understanding" was chosen carefully. It actually means understanding of quantities that cannot be measured experimentally, as opposed to "qualitative understanding" which means knowing, roughly, what is going on. "Prerequite" is used because the pK_a values have to be determined before the other study can begin. "solubility" is a quantitative concept, but "dissolving well" is qualitative, and so on. I put this question to Graham Colm: Surely the use of precise language is important in a featured article, even if the language is somewhat convoluted? The "chore" is rewarded by a deeper understanding of the topic. May I also add that the language has already been given a very thorough going over by Mike Christie, as detailed above. Petergans (talk) 18:24, 22 November 2008 (UTC)

Of course precise language is needed, but I disagree with you regarding convolution. I am watching this page and I will be interested to see what other reviewers have to say. And, with regard to precision, why is there a mixture of " pK_a values" and "pK values" in the article? Graham Colm ^Talk 19:12, 22 November 2008 (UTC)

On the specific point, the subscript may be dropped if it clear from the context that subscript "a" is implied, not the alternative "b". Petergans (talk) 23:09, 22 November 2008 (UTC)

Support and comments. An excellent article, with no obvious errors or omissions (although my chem degree is very ancient). Very clear exposition. Three quibbles

• A knowledge of twice in last sentence of lead
• Factors that determine the relative strengths of acids stray struck through sentence

That was work in progress which is now complete. Petergans (talk) 16:50, 23 November 2008 (UTC)

• Final refs not in numerical order

jimfbleak (talk) 16:18, 23 November 2008 (UTC)

Comments -

• Current ref 9 (Project: Ionic..) is lacking a last access date.

donePetergans (talk) 16:11, 25 November 2008 (UTC)

• Please spell out lesser known abbreviations in the references, such as IUPAC.

done Petergans (talk) 16:11, 25 November 2008 (UTC)

• Current ref 20, the author appears to be http://www.chem.wisc.edu/areas/reich/

How come? I used the citation gadget on my toolbar, which made no mention of author. Petergans (talk) 16:19, 25 November 2008 (UTC)

That's the "home" page for the information in this ref http://www.chem.wisc.edu/areas/reich/pkatable/. The sidebar at the bottom says "This page by Hans J. Reich" also, which would indicate authorship. Ealdgyth - Talk 17:14, 25 November 2008 (UTC)

OK, Reich is the copyright holder for the web-page, but ref. 20 gives the table title "Bordwell pKa Table (Acidity in DMSO) " as Reich has taken the data from Bordwell, who in turn extacted it from the literature. Please suggest how this reference needs to be modified. Petergans (talk) 21:43, 25 November 2008 (UTC)

• Current ref 22 (Rochester, C. H....) needs a page number/chapter/section

This is a general reference as with those in the applications section.Petergans (talk) 16:19, 25 November 2008 (UTC)

• Same for current ref 23 (Olah...), current ref 43 (Dunn...), current ref 43 (Martin...), current ref 44 (brenner...), current ref 45 (Scorpio...), current ref 46 (Beynon...), current ref 47 (Perrin...), current ref 48 (Garfin...), current ref 49 (Hulanicki...), current ref 51 (Avdeef...), current ref 53 (van Leeuwen...), current ref 55 (Stumm...), current ref 56 (Snoeyink...), current ref 57 (Millero...).

Otherwise, sources look okay, links checked out with the link checker tool. Ealdgyth - Talk 14:21, 25 November 2008 (UTC)

Refs 40 and higher numbers are in the "Applications and Significance" section. I asked Peter about specific page numbers for these in a review I did on the talk page; it seems that for many of these references much or all of the work cited covers the topic discussed. I think that means it's OK not to cite page numbers in those cases. Mike Christie (talk) 14:48, 25 November 2008 (UTC)

Heh. How big are these works? If they are 200 pages plus, it's going to be hard to satisfy WP:V if folks have to look through 200 pages. I mean, by that logic, I could just cite a biography of William the Conqueror to two footnotes and have done with it (there are two major scholarly biographies at the moment) since "much or all of the work covers the topic discussed"... Ealdgyth - Talk 14:53, 25 November 2008 (UTC)

WP:V has nothing to do with how much work someone has to do to verify the citation: if it did, we would ban all non-Internet citations and all citations in languages other than English. On the other hand, for example, there are plenty of verifiable citations that Person X is a criminal, but they should not be used for other reasons (eg, X was acquitted on appeal). Whatever happen to WP:AGF? Physchim62 (talk) 15:08, 25 November 2008 (UTC)

Calm, calm, please. I am not suggesting that you've made up anything, just that generally if the work is large, we try to cite a range of pages, or chapters, for the ease of readers following up on citations. I'm not sure why asking for a smaller range of information than a whole work is assuming bad faith. I even asked what size the works are, because if they are small works, then yes, citing the whole work makes sense. Note that WP:V says "The source should be cited clearly and precisely to enable readers to find the text that supports the article content in question. Editors should cite sources fully, providing as much publication information as possible, including page numbers when citing books." Ealdgyth - Talk 15:13, 25 November 2008 (UTC)

(edit conflict) Well, after this comment I'll let Peter reply, since he's familiar with these sources and I'm not, but here's an example of what I meant. "Assessing the hazard associated with an acid or base may require a knowledge of pKa values" is cited to "van Leeuwen, C.J.; Hermens, L. M. (1995). Risk Assessment of Chemicals: An Introduction". My understanding is that the entire book deals with assessing hazards, and that the need for a knowledge of pK_a values is not something that is mentioned only on a specific page. The reference serves not only to verify, but also as a general index to the topic. Since the applications and significance section covers topics at a high level, this seems reasonable to me. I also suspect the statements made here are so generally accepted in the field that they would not be regarded as controversial, and so do not need citations; again I'll wait for Peter to comment on that. Mike Christie (talk) 15:12, 25 November 2008 (UTC)

I've added the page numbers for the risk assessment book. It took all of 30 seconds of Google Books search. I think there may be some culture shock at work here. In my experience, giving page numbers when citing books in chemistry is largely optional in the real world, because all chemistry books worth citing have good indexes and tables of contents. Textbooks and other technical books tend to go through several editions, so the page numbers change even if the facts don't change. As a reader, it is generally more useful to rely on the indexes and forget about the page numbers. --Itub (talk) 15:31, 25 November 2008 (UTC)

Ivan (Itub ) has made all the points that I was making when there was an edit conflict. Petergans (talk) 15:35, 25 November 2008 (UTC)

I understand that in chemistry they don't do page numbers, but this isn't a chemistry book, it's wikipedia. I'm fine with using general references when the work is entirely and only on the subject of the information being sourced, but I'm pretty sure that, for example, the 300 pages of Acidity Functions isn't given over entirely and completely to the Acid Dissociation Constant. I am really not asking the editors of the article to do anything that other articles don't have to do either, or that isn't supported by policy. You're welcome to cite chapters or sections, but when the work isn't devoted completely to the information being sourced, the burden is on the editors to make sure it's verifiable. To use an example from my own writing interests, most scholarly history works have good indexes and tables of content, but this doesn't allow me to just cite a book without a page number or range on a wikipedia article. However, since we're arguing in circles here, I'm more than happy to leave this one out for other reviewers to decide for themselves, it should be something all reviewers consider. Ealdgyth - Talk 17:14, 25 November 2008 (UTC)

And the reference to acidity functions isn't a reference, it's a note as to where more information can be obtained. It is arguably redundant to the wikilink to our acidity function article, but it is truly fair to say that the entire book deals with acid dissociation constants, mainly at a level which would be inappropriate for this article. The sentence should even need a reference, it is so blatantly obvious to anyone who knows what an acidity function is: however, those who propose articles for FA must suffer the consequences, as must the articles themselves it seems. Physchim62 (talk) 18:12, 25 November 2008 (UTC)

Let's not bite Ealdgyth. I am thankful for all her thorough reference checks at FAC, and it's not really her who made up the rules. My opinion is that if it just takes a minute to find something in a book by using the index, the spirit of WP:V is fully satisfied (readers are perfectly able to verify the content of the article, and the policy template at the top of WP:V refers to "use common sense"...), even though the letter of the policy says something about including page numbers. But I don't mind including page numbers when I write; I see it as relatively innocuous compared to some of the many other hoops that need to be jumped at FAC. --Itub (talk) 20:09, 25 November 2008 (UTC)

One way to resolve this issue would be to move all the general references into Further reading, which is what they are there for. Page numbers would then not needed. To have do that would be, in my opinion, a triumph of style over content, but I'd rather do it than prolong this discussion any further. Petergans (talk) 22:17, 25 November 2008 (UTC)

• Oppose. This article, while otherwise well-written and excellently-sourced, is incredibly arcane for most readers. If this were an article about an obscure concept or "deep science" topic, it would be more understandable. That is not the case in this instance, where the article is about a ground-level chemistry topic. The Manual of Style is relevant to this concern, as it addresses both jargon and the accessibility of technical articles. If the current editors are unsure of how to achieve this goal, it may be helpful to recruit an editor or two with some experience in improving the accessibility of scientific topics. This is by no means intended to denigrate the effort expended on the article. I truly appreciate the hard work that has gone into this article, the quality of the sources and the comprehensiveness of the information provided. Vassyana (talk) 15:11, 25 November 2008 (UTC)

  I spent some time reviewing the article and trying to improve the readability. It may be ground-level chemistry in your eyes, but to me, with no chemistry background, it seems quite a technical topic, so I'm not sure what to say there. On the readability question, could you provide some examples of unnecessarily technical prose? Mike Christie (talk) 16:28, 25 November 2008 (UTC)

  Is it really more wikt:arcane than "Prince of the Cumbrians and later King of the Scots. The youngest son of Máel Coluim mac Donnchada and Margaret" or "he became a hanger-on at the court of King Henry I and experienced long exposure to Norman and Anglo-French culture"? Both of them are examples from today's featured article, the bit that's currently on the front page, not the article itself, which is full of examples of terms needing explanation for non-specialists. The acid dissociation constant is neither ground level or specialised. It is usually introduced round about the first year of university studies in chemistry, depending on the country, but is sufficiently complicated that the latest official reference from IUPAC was in 2006. I would invite the opposer to strike the opposition as excessively subjective. Physchim62 (talk) 18:44, 25 November 2008 (UTC)

  I agree that arcaneness lies in the eye of the beholder; for example, I personally find some featured articles about sports hard to understand and full of jargon. I know that "other crap exists" is not a fashionable argument in Wikipedia, but since featured articles are officially considered to be Not Crap, I will venture to try it here. --Itub (talk) 20:23, 25 November 2008 (UTC)

  David I of Scotland is hardly anywhere near as arcane and incomprehensible to a general reader as acid dissociation constant. The strength of an acid in solution is a basic chemistry topic. As you mention, adc is common in first-year chemistry studies. I'm not looking for a miracle or complete rewrite of the article. I am simply looking for some explanation and presentation that will allow a general educated reader to make sense of the topic. I am not a chemist, but I am familiar with the topic and the article was difficult to parse for me. If I already have some passing familiarity with the topic and I find the article difficult to digest, it certainly does not meet WP:MTAA. Vassyana (talk) 01:42, 26 November 2008 (UTC)

  It would really help if you could give some specific examples of sentences or paragraphs that you feel could be improved. Mike Christie (talk) 02:27, 26 November 2008 (UTC)

  The strength of an acid in solution is a basic chemistry topic, but if we covered only the basic level stuff, in a way understandable to the "general reader" we would either end up with a very short article or would have to include a large chunk of a general chemistry textbook as part of the article. The article would also be incomplete and would look more like a textbook than an encyclopedia article. In my opinion, this article already goes out of its way in trying to explain related concepts that are not the main topic of the article, all in the name of accessibility. For more details, see my post in the previous nomination.[1] If you have any specific suggestions on how it can be made more accessible, it would be very helpful. --Itub (talk) 07:04, 26 November 2008 (UTC)

  It is, unfortunately, inevitable that non-scientists will have difficulty in reading scientific articles. The level of difficulty will vary from one person to another. Even people with a scientific background may have to work hard to understand an unfamiliar topic. I think the test should be: if someone is interested in the topic can that person appreciate it, even if it requires some effort over and above the normal effort of reading. Does the article meet that test Vassyana? Let me just add that there is no jargon in the article, only well-established scientific terminology. Petergans (talk) 09:11, 26 November 2008 (UTC)

• (outdent) (edit conflict) Let me be clear in stating that I am not asking for anything to be removed from the article. On the contrary, it would be a detriment to the comprehensiveness to effectively neuter the coverage. However, as currently written and presented, anything outside of the basic definition of the topic is beyond the capacity of the general reader. I strongly disagree that the article "goes out of its way" in any fashion for the sake of accessibility. As I mention above, I know what the article is about and have some familiarity with it, but I still have some serious difficulty in parsing the article. This leads me to believe the article will be almost entirely incomprehensible for the general reader. It is exceedingly difficult to pick apart specific examples for an endemic problem, as this often leads to "patchwork" solutions that do not address the underlying issue. Some specific suggestions:

• The lede. It is dense and difficult to follow. Avoid equations in the introduction. Replace jargon with simpler language. Explain in the plainest language possible, without oversimplifying into the realm of inaccuracy, what the article is about. A couple of examples of what would leave a general reader baffled before they even get through the lede:

• "In aqueous solutions, acids that release a single proton are partially dissociated to an appreciable extent in the pH range pKa ± 2."
• "Structural effects, such as intra-molecular hydrogen bonding, can also be important. pKa can be experimentally determined by potentiometric (pH) titration, but for values of pKa less than about 2 or more than about 11 spectrophotometric or NMR measurements may be required."

• Presentation. The introduction should not be so technical and jargon-heavy that a lay reader will not bother to get through the lede. The general reader should be able to walk away with a solid understanding of what the topic is basically about and how it basically works, while chemistry savvy readers should still be able to walk away with a technical understanding. These are not mutually incompatible goals. The article could generally progress from a layman's explanation to technical details.
• Some basic examples of what needs to be made clear:

• Be clear and explicit that "hydrogen ion" means a proton.
• Be clear and explicit that dissociation, in context, simply means the donation of a proton.
• Be clear and explicit that the adc indicates how readily an acid will donate a proton.

• Some examples of clear language are already extant, but (for a general reader) they are essentially buried in the article. For example, the following is found only after the arcane lede and three mildly technical definitions:

• "The acid donates a proton to the base. The conjugate base is what is left after the acid has lost a proton and the conjugate acid is created when the base gains a proton."

The article is informative, comprehensive and interesting. In contrast, it is equally inaccessible for most readers. The topic is not so specialized or arcane that an accessibile presentation is an unduly burdensome request. Vassyana (talk) 09:41, 26 November 2008 (UTC)

• If I had the slightest suspicion that these criteria were applied consistently to featured article candidates, then I might have some motivation to address them. However, I think this is a classic case of WP:IDONTLIKEIT, of FA reviewers pushing an article to be worse in their attempts to make it jump through arbitrary hoops. Physchim62 (talk) 10:35, 26 November 2008 (UTC)

• Please assume that I am acting in good faith. A request for accessibility does not seem unreasonable or an undue burden for a relatively basic chemistry topic. The Manual of Style addresses the accessibility of technical topics. As it relates to both MoS requirements and comprehensible prose, the objection is clearly relevant to FA criteria 1a and 2. Vassyana (talk) 11:12, 26 November 2008 (UTC)

• Vassyana, I understand your concerns, but you are making the assumption that simpler language is always possible. If that were true it would have been done already. You are confusing jargon, which is a kind of slang, with scientific terminology which allows for precise expression of concepts. Let me deconstruct the sentence "In aqueous solutions, acids that release a single proton are partially dissociated to an appreciable extent in the pH range pKa ± 2" to illustrate what I mean. aqueous - in water; solution - to distinguish from solid or gas; acid - a particular kind of chemical compound; single - to distinguish from acids in general; proton - the particle that is released; partially - to distinguish from complete; dissociated - as in the topic title; appreciable - giving rise to an observable effect; pH range - a quantitative statement showing how the title subject can be applied. The lead-in is necessarily terse as it is a summary. BTW you have not answered my question, above, so I will repeat it. If someone is initially interested in the topic can that person appreciate it, even if it requires some effort over and above the normal effort of reading? Please try to give an objective answer, not just one based on your personal experience. Petergans (talk) 14:31, 26 November 2008 (UTC)

• I am asserting that some complementary simpler language is possible for entry-level topics, not that it is always possible for academic topics. I have stricken the reference to jargon, as it is inaccurate as you correctly point out. However, the absence of jargon does not preclude problems with general accessibility. There is no reason that a general audience treatment cannot accompany the more precise and exacting treatment. I did not raise an issue with the terseness of the lede. I expressed concern that it was dense and difficult to follow. To put it another way, the lede is complex and bewildering for a general reader. No, I do not believe the article would generally be appreciated by someone with an initial interest in the topic. For the most part, it will only be useful and interesting to readers with a solid grounding in chemistry and/or familiar with the specific topic. Vassyana (talk) 15:27, 26 November 2008 (UTC)

• (outdent) I can't help chipping in here. I'm sure that Vassyana is acting in good faith, but I think he is misguided. To make the article "accessible" it would have to be dumbed down to a level at which it is essentially meaningless in terms of the article title. I don't think that it's an FA criterion that the reader doesn't have to put in some effort on the more intellectually demanding areas. The Problem of Apollonius isn't an easy read either (first sentence starts In Euclidean plane geometry, Apollonius' problem is to construct circles that are tangent...) - perhaps that article should be sent to FA review? jimfbleak (talk) 14:54, 26 November 2008 (UTC)

I think I might have started this discussion. I never meant to suggest that scientific terms should not be used or imply that the article should be turned into baby food. It was the use of expressions like "when operating under the assumption that" and other wordy phrases that rattled my cage. I have withdrawn my opposition, but I wish the nominator would make some effort to address these criticisms—I cannot see any changes to the article that have been made in an attempt to reach a consensus on this. Graham Colm ^Talk 15:09, 26 November 2008 (UTC)

• (ec) I'm not asking that the article as a whole be "dumbed down". I state multiple times above that I am not looking for material to be removed. I am asking for additional material that allows a general reader to comprehend the topic. Vassyana (talk) 15:27, 26 November 2008 (UTC)

• The problem is that the MoS is inconsistent, and Vassyana is only using those parts which appeal. The article as it stands in 69k of wikitext. A relatively high proportion (compared to other FACs) of that is in tabular material, equations and references. WP:SIZE comments that "Readers may tire of reading a page much longer than about 30 to 50 KB, which roughly corresponds to 6,000 to 10,000 words of readable prose." The article is at 5000 readable words, without counting tables and equations, by a quick run through a well-known word processor. Let us accept that, with equations, technical language and tabular material, the article is 'content-dense'. So, should the authors:

1. expand the article, thereby risking FACR 4 and WP:SIZE (personally, I find it ironic that this should even be suggested, given that Vassyana apparently finds the article difficult to read already); or
2. move material to other articles, thereby risking FACR 1(b); or
3. remove material, thereby risking FACR 1(a–d), and in particular FACR 1(a) which states that the prose should be of a "professional standard"?

• I'm honestly (but only intellectually) interested in comments. Physchim62 (talk) 18:45, 26 November 2008 (UTC)

The "readable prose size" of the article is only 27Kb; I don't think there's any risk of the article becoming too long. I don't see any suggestions to trim it by moving or cutting material, so I think we're OK there. I'm not sure what Vassyana meant by "additional material", but given his earlier comments it may be that he is still looking for some rephrasing.

I copyedited the article myself, and by the time I was done I felt the article was clearly written. However, every copyeditor has blind spots, and I think it's entirely possible that another pass by a copyeditor familiar with technical writing would help. Graham's example of wordy prose ("when operating under the assumption that") could probably be improved. The point at issue doesn't seem to be whether the material is accurate or complete, just whether it could be rephrased in a way that would be more readable to a non-technical audience. Chemistry reference works are likely to elide explanations that are helpful to general readers; but conversely, few general readers will find their way to this article, and some understanding of the background facts of basic chemistry can be assumed. We're not going to explain what an atom is, for example; and I'd say that the fact that a hydrogen ion is a proton is something that doesn't need to be made explicit here. But another look at the prose with an eye to readability is a good idea. I will ask someone to take a look, but they may not have the time or inclination to help, so it would also be good if the chemists reading this could try to look at the prose with a fresh eye. There may well be places, such as the phrase Graham mentioned, where improvements can be made. Mike Christie (talk) 20:23, 26 November 2008 (UTC)

I've made some changes to the lead, to try to introduce the subject as clearly as possible to people with no background in chemistry. Tim Vickers (talk) 21:19, 26 November 2008 (UTC)

Thank you Tim!, at last we have another editor who sees the bigger picture. The Lead is much improved—the whole article needs similar attention (IMHO).Graham Colm ^Talk 21:37, 26 November 2008 (UTC)

Nothing that TimVickers reverted his edits per objections here. SandyGeorgia (Talk) 18:47, 28 November 2008 (UTC)

• Oppose for the moment. If that's an "improvement" in the eye's of FAC reviewers, then I can only implore the nominator to withdraw the candidacy. While acting in the best of faith, Tim has substituted precise and incorrect terms for precise and correct ones, so nixing the scientific value of the lead. Physchim62 (talk) 22:00, 26 November 2008 (UTC)

I'm sorry, which piece did I get wrong? Tim Vickers (talk) 22:31, 26 November 2008 (UTC)

Was that the problem? But you said "terms" so there must be something else. Tim Vickers (talk) 22:34, 26 November 2008 (UTC)

That was the worst, with serious errors on both lines edited, but this is also very confusing from the point of view of complex formation. Physchim62 (talk) 23:20, 26 November 2008 (UTC)

I've placed the science on the article talk page, as this page is already getting long. It seems that my objection to the second edit wasn't Tim's fault at all: my apologies. It's amazing how you miss things when you've read an article too many times… Physchim62 (talk) 00:35, 27 November 2008 (UTC)

I agree with Physchim62, the scientific content has been seriously degraded and some edits are unacceptable. May I make two pleas:

1. Don't edit the text unless you are thoroughly conversant with the subject matter and understand the technical terms.
2. Do your edits first in a sandbox. Its going to take me ages to work through the dozens of multiple edits from the last few days.

One of the things that concerned us when preparing the article for FAC was length. If, as now appears to be the case, length is not an issue, I can certainly expand some parts and give more explanation. Petergans (talk) 22:57, 26 November 2008 (UTC)

OK, since I seem to have accidentally introduced other errors that I didn't catch, I've reverted my changes. I'm sorry to have caused any problem. Tim Vickers (talk) 23:09, 26 November 2008 (UTC)

I can't find the exact comment now, but one previous criticism was that the older version of the article used a sort of 'semi-summary' style. Another way of improving the readability would be move some of the discussion of, for example, non-aqueous solvents to their respective articles, linked with a {{main}} tag but retaining enough information here to illustrate the importance of the specific (linked) topic. IMHO! Physchim62 (talk) 23:20, 26 November 2008 (UTC)

Final revisions

• Thank you, Tim, for withdrawing your edits. The current text has been very finely honed over a long period of time. Clarity cannot be improved by merely tinkering with it. I have therefore gone through the entire text again, trying to improve clarity. The major changes are
  • modified lead-in
  • introduced the image for the thermodynamic standard sign
  • removed the paragraph "When operating under the assumption ..." This was added by user:eaglefalconn and I have left it in up till out of respect for that editor. In its place I've added a brief description of how to make a buffer solution, in the section monoprotic acids.
  • clarified the bit about strong acids
• If any further changes might seem desirable then please be specific about them; I can't amend generalities. Petergans (talk) 11:30, 27 November 2008 (UTC)

• Comment: I would strongly suggest putting the sentence of the lead

  For an acid-base equilibrium between a generic acid (HA) and its conjugate base (A⁻), HA ⇌ A⁻ + H⁺. K_a is defined, subject to certain conditions, as

$K_{a}=\mathrm {\frac {[A^{-}][H^{+}]}{[HA]}}$

where [HA], [A⁻] and [H⁺] are equilibrium concentrations of the reactants.

in words.Headbomb {^ταλκ_{κοντριβς} – WP Physics} 02:28, 28 November 2008 (UTC)

• Oppose: After reading part of the article, it's completely inaccessible. I'm a master's student in physics, (I started in chemistry), and I can barely make sense the lead even after multiple reads! The lead contains weird sentences, some with vague statements such as "under certain conditions" (which?), or some overly technical/precise such as "the larger the value the more the acid is dissociated, at a given concentration, into its conjugate base and the hydrogen ion." etc... Needs to be re-written so readers don't spent half an hour trying to figure out what exactly is the article talking about. More examples below

• Introduces technical concepts with little to no explanation for laypeople

Monoprotic acid/polyprotic (in the lead), what are they?

• Gibbs free energy is thrown as if we all know what it represents
• Same goes for enthalphy
• Exothermic and endothermic could probably be changed into (releases energy) and (absorbs energy) or something similar
• "Acidic behaviour can also be characterised in non-aqueous solutions." such as...?
• "Pauling's rules" wikiling that would probably be a good idea.
• Etc...

Headbomb {^ταλκ_{κοντριβς} – WP Physics} 02:44, 28 November 2008 (UTC)

• Oppose: The lead is far too technical. Describe the formula (Ratio of Products and Educts). Don't assume the reader to know what is log_10. etc... There are so many examples which have been described above. Vb (talk) 09:54, 28 November 2008 (UTC)

Reply to last two The artice conforms to Wikipedia:Featured article criteria. Nowhere in those criteria does it say that the article has to understandable by everyone. Rather, the first sentence is "A featured article exemplifies our very best work and features professional standards of writing and presentation". This is a professional presentation of the subject matter. For an elementary introduction look to a school chemistry book. Petergans (talk) 10:57, 28 November 2008 (UTC)

The criteria states it must be "well-written: its prose is engaging, even brilliant, and of a professional standard"...the comments above demonstrate a not well-written article.--JEF (talk) 23:01, 28 November 2008 (UTC)

What JEF said. "Professional" does not mean "understandable by only trained professionals". There are things in science that are too complicated to be really understood by layfolks because they are so arcane and abstract, just pick any subject in condensed matter physics. What the acid dissociation constant is is something that can be understood even by high school students. While there's a lot more than what high school covers that can be said about it, it never becomes so complicated that scientists that are not chemists can't get the hang of it. This is not about sacrificing scientific accuracy for a lie-to-children type of thing, it's simply about writing for a non-specialist audience.Headbomb {^ταλκ_{κοντριβς} – WP Physics} 23:31, 28 November 2008 (UTC)

These comments apply only to the lead-in. The lead-in is a summary, not the place to introduce details. Once the reader starts on the body of the article, the language become much simpler and explanations are given. Rutherford is quoted as having said that any scientific topic should be capable of being explained to a barmaid. I agree. If I had an attentive barmaid and a day or two to do it, I could explain it to her. After that, she would probably be able to understand the lead-in, but I would probably be banned from the bar!

In reply to JEF, both jimfbleak and Vassyana have said (above) that the article is well-written. Mike Christie has said that it is clearly written. Petergans (talk) 10:45, 29 November 2008 (UTC)

Well, I disagree. IMO, the lead is the place to summarize things in a way people can understand them, and I do not consider articles with such a technical lead relative to the subjects inherent complexity to be Wikipedia's finest.Headbomb {^ταλκ_{κοντριβς} – WP Physics} 17:06, 29 November 2008 (UTC)

Simply repeating your point is not getting us anywhere. Believe me, if I knew of any way to present this complex material in a simpler way it would have been done long ago. Tim Vickers made an honest attempt at broadening the appeal. While this was welcomed by some, like Graham Colm because it appeared to do the job, in fact it was completely unacceptable from the scientific point of view. What is needed is constructive criticism. So far I have only seen suggestions which amount to dumbing down and these are not professionally acceptable. Petergans (talk) 21:38, 29 November 2008 (UTC)

Oppose - As a Chemistry Education major, I feel this article is not Featured Article status. I have not gone through the entire revised article, but the parts that I have I find access and comprehensiveness issues. The ones I am about to mention are easily fixed but point to a lack of quality:

• K_b is explained as "Historically the equilibrium constant K_b for a base was defined as the association constant for protonation of the base, B, to form the conjugate acid, HB⁺." An explanation of this in simpler terms should have followed. The K_b is the inverse of the K_a. It is the opposite of the K_a, which has the formation of the conjugate base on top, as the K_b has the formation of the conjugate acid on top.
• How can you mention K_w without mentioning that at SATP its value is 1.0×10⁻¹⁴. This is the value that the entire pH scale is based off of.
• I had to change "In common parlance the acid is said to be fully dissociated." to "It is thus referred to as fully dissociated (even though it is technically not)" which was then changed to "Hydrochloric acid is said to be "fully dissociated" in aqueous solution because the amount of undissociated acid is imperceptible." The third statement is not even true. Of course the undissassociated acid is perceptible, that is why it has an estimated pK_a of -9.3 and not -infinity. Negligible would have been the appropriate word to use there.--JEF (talk) 04:09, 30 November 2008 (UTC)

Really? It makes more sense to state that K_b is the inverse of K_a? It may be mathematically true, but is neither informative nor always chemically intuitive. K_b is the association constant of a base with a proton. It does not require that you care about the conjugate acid. Its just an equilibrium constant like the acid dissociation constant. And for this reason, there is no article on base dissociation constant, because its a redundancy (hence the term historically).

The pH scale is not in any way dependent on the value of K_w. Nor is the definition of pH. The only thing dependent on K_w is whether we consider something acidic or basic in aqueous media, which as the current article addresses is not the only possible solvent and that pK_as will change across solvents. I will agree that not mentioning its value was an oversight, but its not as big a deal as you make it out to be.

I don't understand your quibble with how I originally phrased the point about HCl dissociation levels. The first variation of that sentence says everything that the second and third one says in fewer words. Also, that estimated pK_a does not come from experiment, it comes from estimation from determining the change in Gibbs Free Energy for the reaction. So no, imperceptible may still be correct. EagleFalconn (talk) 06:40, 30 November 2008 (UTC)

All three of Jorfer's bullet points are wrong; this is the perfect example of the dangers of oversimplification. 1) Kb is not the inverse of Ka. In water, it is Kw/Ka. It is not even the equilibrium constant for the reverse reaction, and it could only be called an "inverse" in a very loose sense. 2) There is no such thing as a pH "scale". A common misconception, usually introduced in middle or high school, is that pH can only go from 0 to 14, which look suspiciously related to Kw. But in fact, pH is not fundamentally restricted to this range, even in water. However, I agree that mentioning the value of Kw wouldn't hurt. 3) As far as I know, the association of HCl in dilute aqueous solution is in fact imperceptible (i.e., cannot be detected experimentally using current methods). The pKa can be estimated from extrapolations from other solvents, or thermodynamic or theoretical data. But as far as I know it can't be measured directly in aqueous solution. --Itub (talk) 07:48, 30 November 2008 (UTC)

Well, since the article discusses everything in terms of K_a, it is simpler to explain K_b as the opposite of K_a (acid association is the opposite of acid disassociation). For Itub, since K_w is accepted to be a constant at a given temperature and pressure, Kw/Ka = Constant x 1/K_a, thus K_b is inversely proportional to K_a, since it is the value of the opposite process.

Regardless of the actual legitimacy of the pH scale as presented in middle and high school, the pH value of 7 is considered neutral in it because of the SATP value of K_w.

My quibble about the HCl acid sentence is that it originally used the term parlance, the word vernacular easily would have improved access to the article without taking away any content as has been argued about making the article make more sense. Whatever the case, further explanation was important in improving access to the article. The problem with imperceptible was negligible gives a better idea than imperceptible even though imperceptible does not mean unable to be perceived which I originally thought before looking it up. Since the pKa is said to be taken from thermodynamics, it is perceptible (temperature can be felt so it is perceivable), so even though imperceptible can accommodate a barely perceptible phenomenon, negligible would be more exact.

The point of this is that this is just evidence of an article not ready for featured article status rather than the sole problems needing to be fixed to be featured article worthy.--JEF (talk) 20:23, 30 November 2008 (UTC)

But K_b is not the opposate of K_a! See my and Itub's earlier comments to this point.

pH of 7 is considered neutral for water ONLY.

Parlance - Noun, Manner or mode of speech. Vernacular - Adjective, using a language or dialect native to a region or country rather than a literary, cultured, or foreign language (both from Merriam Webster). A subtle difference, but regardless of which term you prefer it doesn't significantly change the meaning of the article enough to merit voting it down. As you mention, you previously incorrectly used the word imperceptible. You should probably look up thermodynamics since you're misuing that word too. Please stop critisizing content of articles for which you are not well versed. EagleFalconn (talk) 20:47, 30 November 2008 (UTC)

• Strong Support and Strong Comments. This article is exceptionally well written, with the possible exception of the lead (see below). It leaves out no detail, and is presented in such a way that any reader with a high school understanding of chemistry and an introduction to basic equilibria would be able to follow. Regarding the lead: While the lead is somewhat opaque, I think this is a resolvable issue. See my proposed lead here. It maintains the vast majority of the details of the lead, which follows a logical structure of qualitatively defining the ADC, quantitatively defining it and then defining some of its basic aspects, followed by its broader applications.

  The proposed lead is fine apart from one point. The temperature dependence of K_a is mentioned a couple of sentences later. I have added a sentence to explain that K_a values are dependent on the ionic strength of the medium in which they are determined. I have substituted it, with that modification, into the article. Petergans (talk) 09:35, 30 November 2008 (UTC)

For those who are worried about "undefined terms" in the lead: This is not a basic chemical article. It does require an introduction to chemistry. But what you are requiring in terms of detail and introduction in the lead would require an article to be created, "Introduction to the Acid dissociation constant article." It is logically inconsistant and a slipperly slope for Petergans to not be able to assume that (and I'm pulling examples out of the FAC Nom comments) readers will not know what a logarithm is, the structure of the atom (Hydrogen ion = proton), dissociation = splitting of a chemical compound into two or more parts (all previous suggested by Vassyana), definitions of exothermic and endothermic, that non-aqueous is defined and discussed later in the article (and the lead does actually link to a later part of the article), monoprotic versus polyprotic acids....should we start including these in the lead of every chemistry article? EagleFalconn (talk) 07:15, 30 November 2008 (UTC)

Oppose Unreadable for non specialists. Especially the lead is incomprehensible to non-chemists. Commenting on the issues above a summary or lead should be the hook for the article. Is the lead is more complex for the interested non-expert reader than the body text of the article, the lead fails big time. In my opinion, simplification is sometimes acceptable for the lead; where the body text of the article has some depth that maybe too technical, these should not feature in the lead. Missing out on some sections in the body text means missing out on details, losing it in the lead will result in a reader never starting the body text at all. Arnoutf (talk) 16:37, 30 November 2008 (UTC)

Arnoutf - Out of curiosity, what is your background/familiarity with chemistry? I will grudgingly continue to conceed that the lead may need revising to be non-expert accessible, but theres only so much of a general chemistry textbook that it makes sense to include in the lead. Unless you know what types of acids there are, some basic equilibrium chemistry etc the acid dissociation constant is a worthless article to read anyway. Thats why there are wikilinks in the lead so that you can go to those articles, understand them, and then come back and understand this article.

Also, I strongly disagree about the body being "too technical." To be less technical would result in using qualitative ideas where only quantitative ones are appropriate, or handwaving concepts or artificially invoking them where this is not necessary. There is NOTHING in the lead that I consider to be overtly technical except the mathematical definition of K_a. There is terminology used, but as I said before, if you do not understand the terms used in the lead you are NOT capable of understanding the article anyway. Which, again, is why wikilinks exist. EagleFalconn (talk) 20:49, 30 November 2008 (UTC)