Wikipedia:Articles for deletion/Silicic acid

The following discussion is an archived debate of the proposed deletion of the article below. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.

The result was keep. It would be a speedy or snow keep if this hadn't somehow stayed open for a week, because the nomination contains no valid argument for deletion and frankly, if a topic appears in the EB, there is no question that it should be included in Wikipedia. @Petergans: With the greatest of respect, I think you have misunderstood both our basis for including articles and our basis for deleting them. You are free to replace this version of the article with one that reflects the latest research and/or move it to a more appropriate title. It doesn't need to be deleted first. – Joe (talk) 15:01, 28 July 2018 (UTC)[reply]

Silicic acid[edit]

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This article is purely conjectural. There is almost no published evidence for the existence of silicic acid. The best reference that I can find is R.K. Iler (1979), "The chemistry of silica: solubility...". Greenwood & Earnshaw(2nd, p. 346, table 9.9) quote a solubility for "orthsilicic acid" of 7*10^-4M, presumably from that reference, but no temperature or other details are given. Petergans (talk) 10:07, 21 July 2018 (UTC)[reply]

Keep. The topic is notable. There is, for example, an article on this topic at Encylopedia Britanica: https://www.britannica.com/science/silicic-acid. There are literally thousands of scientific articles with "silicic acid" in the title. This is a problem that should be solved through editing (possibly by reverting to an older version of the article if the major changes made in May 2018 are the concern), rather than by deletion. We have plenty of article about chemical compounds that don't actually exist (see Category:Hypothetical chemical compounds for some examples) so that isn't a reason alone to delete an article. They are included in Wikipedia because they are discussed in reliable secondary sources. The key in these situations is to clearly and accurately describe what is known about the chemical and what isn't. ChemNerd (talk) 14:00, 21 July 2018 (UTC)[reply]

Thank you for your helpful comment. May I point out that I believe the citations to be fictitious. Certainly there is no mention of a silicic acid in Greenwood & Earnshaw, 2nd. edn. Petergans (talk) 07:01, 22 July 2018 (UTC)[reply]

I apologize, but I am genuinely confused by your use of "fictitious".

For reference's sake: "...there are also numerous hydrates and distinct silicic acids in very dilute aqueous solutions, but these tend to be rather insoluble and rapidly precipitate with further condensation when aqueous solutions of soluble silicates are acidified. Structural information is sparse, particularly for the solid state, but in solution evidence has been claimed for at least 5 species (Table 9.9). It is unlikely that any of these species exist in the solid state since precipitation is accompanied by further condensation and cross-linking to form "polysilicic acids" of indefinite and variable composition [SiO
_x(OH)
_4-2x]_n" Greenwood and Earnshaw second edition, p. 346.

The problem here is that the information in table 9.9 (G&E) appears to be unreferenced. The phrase "evidence has been claimed" is very suspicious. I will accept these claims if an original publication can be referenced. Petergans (talk) 21:12, 22 July 2018 (UTC)[reply]

Reference 2 is R. K. Iler, The Chemistry of Silica (1979). Quoting p. 180, from among many uses of the term: "Characteristics of Silicic Acid: Since Si(OH)
₄ has never been isolated or even obtained in a concentrated solution without considerable polymerization, very little is known about its physical or chemical properties. Most measurements have therefore been made in very dilute solutions."

Just so. It's all speculation. Petergans (talk) 21:12, 22 July 2018 (UTC)[reply]

But, more recently: "Although the dominant silicate species in solution is usually the silicic acid monomer [...] many important processes and reactions, including gel and colloid formation and solubilization of toxic metals, are associated with larger oligomers that become populated only at high concentrations. It is generally accepted that 16 distinct oligomers beyond the dimer have been conclusively identified in aqueous solutions to date, with the largest of these containing eight silicon atoms" Cho et al. (2006).

~~I'll check that one. It doesn't sound like anything that is in the article at present. I would expect some similarity with oligophosphoric acids. Petergans (talk) 21:12, 22 July 2018 (UTC)~~[reply]

~~Unfortunately the abstract does not specify which solvent was used. Can you obtain the information? Petergans (talk) 10:49, 23 July 2018 (UTC)~~[reply]

This article is concerned with silicates, not silicic acid(s) Petergans (talk) 15:54, 27 July 2018 (UTC)[reply]

And: "Here we show a simple procedure to selectively synthesize orthosilicic acid and its dimer, cyclic trimer and tetramer in organic solvents. Isolation of orthosilicic acid, the dimer and the cyclic tetramer as hydrogen-bonded crystals with tetrabutylammonium halides and the cyclic trimer as solvent-containing crystals is also described. The solid-state structures of these compounds are unambiguously clarified by single crystal X-ray and neutron diffraction studies." Igarashi et al. (2017).

This is citeable. Note: the solvent was based on DMSO Petergans (talk) 21:12, 22 July 2018 (UTC)[reply]

We have articles on substances that are only hypothetical, or even purely fictional. Being difficult to isolate, hard to characterize, known primarily for its derivatives, etc., are not reasons to be excluded from an encyclopedia. XOR'easter (talk) 16:26, 22 July 2018 (UTC)[reply]

I strongly deprecate the inclusion of speculation in WP. One of the basic tenets is that material should be verifiable. Petergans (talk)}

But speculation, done by scientists — whose job is in part to speculate — is verifiable. Our duty here includes the reporting of conjectures and untested hypotheses. The Higgs boson did not suddenly become an encyclopedic topic in July 2012. Planet Nine might not exist at all, but the astronomers have good reason to think it might, and what they have said on the subject is eminently verifiable. The same applies, for example, to conjectures about chemical behavior of short-lived isotopes. Our article on tennessine says that it "is expected to be a volatile metal that neither forms anions nor achieves high oxidation states". This cannot yet be tested in the laboratory, but that's not what "verifiability" means where Wikipedia policy is concerned. XOR'easter (talk) 22:34, 22 July 2018 (UTC)[reply]

Addendum While looking for recent-ish overviews of this topic, I found "the silicon content of beer". I think that's a sign I should go take a drink. XOR'easter (talk) 23:00, 22 July 2018 (UTC)[reply]

Cheers! My point is that there is a difference between prediction - as published by Higgs - and speculation, or to put more crudely, guesswork. It is obvious that there should be similarities between silicate and phosphate chemistry as the elements are neighbours in the periodic table. That Si(OH)₄ is not observed with aqueous solutions is a result of the insolubility of its anhydride, SiO₂. Petergans (talk) 10:49, 23 July 2018 (UTC)[reply]

Keep Heck, it's even in my old print edition of the EB, on pp. 805 and 809 of volume 10 (Réti to Solovets). Add to that 2,700+ hits on JSTOR, a couple thousand exact-title matches on WorldCat, and over 93,000 hits on Google Scholar, and it's plain that we ought to have an article under this name. Problems can be solved through the regular course of editing (which includes reverting, as mentioned above). XOR'easter (talk) 16:33, 21 July 2018 (UTC)[reply]

I have found many literature references to substances such as "silicic acid, sodium salt". These clearly do not refer to silicic acid itself, the topic of the article under consideration here. Petergans (talk) 08:08, 22 July 2018 (UTC)[reply]

Keep Silica is very slightly soluble in water, forming stable solutions. (Diatoms depend on silica dissolved in seawater, phytoliths are formed from silica dissolved in sap, etc.) I have seen no claim that the solution consists of neutral SiO
₂ molecules or polymers thereof. All sources that I have seen that discuss the subject assume that it gets hydrated forming silicic acid and silicate ions (and one could not have one without the other, correct?) Thus silicic acids are no more 'fictitious' than carbonic acid, or the hundreds of compounds that have been detected only in very extreme situations like outer space or trapped in solid argon.
If you give me a few days, I will try to find a more positive recent reference with concrete evidence for those compounds.--Jorge Stolfi (talk) 00:53, 23 July 2018 (UTC)[reply]

That's interesting, but unfortunately not conclusive. The skeletal silica may be formed from silicate ions which are present in seawater. Petergans (talk) 10:49, 23 July 2018 (UTC)[reply]

Keep. If Britannica has an article, plus the other references mentioned above, it's an encyclopedic topic. I take the nominator's views very seriously given their career, but I think this applies whether they're right or not. The question is, if the claims are false, can they be debunked within the article without using WP:OR? The notability of the topic, whether as a real acid or a widely-held misconception, seems clear. The article should remain either way. Mortee (talk) 03:01, 25 July 2018 (UTC)[reply]

The problem arises because there are two distinct chemical entities which, in common usage, may be called by the name "silicic acid". The chemical formulae are SiO₂ and Si(OH)₄, which clearly are not the same. This will need to be explained. Petergans (talk) 16:35, 25 July 2018 (UTC)[reply]

I think SiO, and SiOH are the same compound- an oxide of Si (silicon). The difference in presence or absence of the H is due to the availability or scarcity of hydrogen, added in more acidic conditions. (This is simple inorganic chemistry)! — Preceding unsigned comment added by 199.19.248.204 (talk) 01:01, 27 July 2018 (UTC)[reply]

~~Delete~~ The use of the term "silicic acid" was unambiguous and was used for the species silicon dioxide in its various forms. Strictly speaking a compound with the formula SiO₂ should be called "silicic acid anhydride. Then, with the publication, in 2017, of the paper by Igarashi et al. (2017), a compound with the chemical formula Si(OH)₄ was synthesized and was called orthosilicic acid. Thanks to user:XOR'easter for finding this article. In consequence the term "silicic acid" has become ambiguous as it can refer to compounds with different chemical formulae. Nothing in the present article refers to the compound with the formula Si(OH)₄. Therefore the article should be deleted. I have prepared an alternative article in my sandbox. I suggest that it's title could be Silicic acids as the paper describes more than one compound that can be described as a silicic acid. If this is agreed, I will add new section to the article silicon dioxide to clarify the possible confusion caused by the historic use of the term silicic acid. Petergans (talk) 10:27, 28 July 2018 (UTC)[reply]

Note: This discussion has been included in the list of Science-related deletion discussions. XOR'easter (talk) 16:16, 21 July 2018 (UTC)[reply]

The above discussion is preserved as an archive of the debate. Please do not modify it. Subsequent comments should be made on the appropriate discussion page (such as the article's talk page or in a deletion review). No further edits should be made to this page.