Talk:Hydrochloric acid/Archive 1

What is the pH of Hydrochloric acid?
I couldn't find it in the article.


 * Like any other acid, the pH depends on the concentration. It can be anywhere from 7 to -2 or so. --Carnildo 21:19, 8 Apr 2005 (UTC)
 * For the common concentrations, it is in the table now. Obviously, if you dilute it more, pH increase up to (max) 7. Lowest is about -1.1, as shown in the table. Wim van Dorst 22:15, 2005 Apr 8 (UTC).

For every tenfold dilution the pH goes up by 1 pH unit until you come close to pH 7. Cacycle 22:54, 8 Apr 2005 (UTC)

What about pure HCl?

Does not have a pH at all. Cacycle 08:55, 9 Apr 2005 (UTC)

i.e., if you have pure hydrogen chloride gas, there is no water, and the definition of pH requires water. If you mean what is the pKa, I see that the hydrogen chloride page lists this as -4. Walkerma 21:46, 9 Apr 2005 (UTC)

Doesn't acid need to be aqueous to be, well acidic, anyway? Isn't HCl in non aqueous form, well, non-reactive? Hydrogen chloride? -- Natalinasmpf 06:01, 25 Apr 2005 (UTC)

Yes, it does need to be aqueous to have a pH, per the definition of the pH. But HCl in pure form is also very reactive. Wim van Dorst 12:35, 2005 Apr 25 (UTC).

Yes, but that only happens when its mixed with organic material, because they organic molecules are bound to contain oxygen and hydrogen to create an immediate ionisation effect - forming the same negative chlorine ion and the positive ion of the other side of the molecule. Which is the key to hydrochloric acid's corrosiveness. Hydrogen chloride won't corrode metals by itself, unless you decided to add some sort of organic/water molecule to it. Which is the key difference with the disassociation effect, thus has less oppurtunies to corrode. Because from what I see, hydrogen chloride only reacts when it reacts with an organic molecule/water and becomes hydrochloric acid; it has to make that transformation. It still isn't corrosive by itself. -- Natalinasmpf 18:28, 26 Apr 2005 (UTC)

Okay, you guys have me confused. I recently took a chemistry class at one of the top colleges in the United States. There, we supposedly had and worked with "pure molar" Hydrochloric Acid, listed at somewhere around 16. Obviously, if Hydrochloric Acid is a solution and therefore a homogenous mixture in a water solvent, it could not be listed as pure from a molar aspect. However, we were never given a pH, and the molar scale is generally considered more accurate. Can anyone help me out with my confusion?207.118.41.6 06:06, 20 May 2007 (UTC)


 * There is no such thing as "pure molar" hydrochloric acid. 100% (anhydrous) "hydrochloric acid" is actually hydrogen chloride gas, a distinct chemical.  The dissolution of hydrogen chloride in water produces hydrochloric acid, in the same manner that the dissolution of sodium chloride in water produces salt water.  Hydrochloric acid is typically stored at a maximum concentration of about 38% (w/v), as it isn't very stable above that concentration (too much of it vaporizes to make it practical or safe for use).  Acid solutions aren't typically measured by pH, because it is not nearly as accurate or easy to measure as other units (mass and volume for molarity).  However, as a reference, 3.647% (w/v) or 1M hydrochloric acid has a pH of 0.0.  Remember that "pure" can just as easily imply "free of contaminants" as it can "100%" - as to why your professors or TAs chose to label something as "pure molar," I am unsure, because it should have been labeled with a quantitative value for molarity or w/v percentage.  Hope this helps! Dcteas17 06:52, 20 May 2007 (UTC)

It did help as much as the Wikipedia article, which is what gave me this confusion in the first place. :) The bottle was labeled ~16M, and the term "pure molar Hydrochloric Acid" is a direct quote from the professor. 16*3.647=58.352, so perhaps this was a maximum saturation of HCl in H2O?69.29.209.192 07:03, 23 May 2007 (UTC)

I'm having trouble with two phrases in this section: "i.e., if you have pure hydrogen chloride gas, there is no water, and the definition of pH requires water" and "Yes, it does need to be aqueous to have a pH, per the definition of the pH". I only know this definition of pH: the cologarithm of the activity of dissolved hydrogen ions. In this definition, water is not mentioned. So you can also determine pH in organic solvents and -in a total theoretical way- in any "solvent". I was just wondering because I often make solutions in organic solvents. I am wrong in saying that for example a solution of HCl in methanol has a pH? Ikbentbeu (talk) 12:35, 24 April 2009 (UTC)
 * The definition of pH requires a solvent, which usually is water. But there is a pH in other solvents too, although you shouldn't expect the neutral value to be '7'.  Wim van Dorst  (talk)  20:55, 24 April 2009 (UTC).

tables and infobox
well done. 141.213.129.41 02:30, 25 Apr 2005 (UTC) the pH is around 2, making it a strong acid. it is found in the stomach, where it catalyses the action of pepsin on proteins, but also kills bacteria.

As Weapon of Misogynists
Hydrochloric Acid is used in South Asia for domestic use, largely as a toilet cleaner. But another use is by men attacking women in a phenomenon that cuts across the boundaries of India and Pakistan, and while other acids are also used, HCl is the preferred weapon. 99% of attacks are by men on women, though there are some by women on men. This is an issue that needs to be addressed. Is this the correct place?

http://www.womensenews.org/article.cfm/dyn/aid/1908/context/archive http://ww1.mid-day.com/news/city/2005/april/107660.htm


 * I think there should be a separate article on Misogynist attacks in Asia. Anyone who has Internet access can write such an article.  For example, if you are in Wikipedia now and you see the red lettering in Misogynist attacks, you can simply put your mouse pointer on the red lettering and click, and a page will appear where you can start writing such an article.  If somebody else starts writing such an article and the link becomes blue (from red), you can still edit the article that was started, giving more information.  It would be a good idea to log in under a registered User (member) name when writing the article, but it is not necessary.  Also, if you think the article should have a different title, then you can start one with a different title by searching for the alternate title in the margin to the left of this page.  If an article with that title is not found, you can start a new one.  H Padleckas 17:00, 25 Apr 2005 (UTC)


 * Have done it as "Misogynist_Acid_attacks", but perhaps it is not yet uploaded? I am getting this message: "If you have created this page in the past few minutes and it has not yet appeared, it may not be visible due to a delay in updating the database. Please wait and check again later before attempting to recreate the page."

The article seems not to exist, unfortunately. However, you should wait for let's say two days before recreating it as I have had such problems too and the article appeared only after about a day. --Eleassar777 16:04, 28 Apr 2005 (UTC)


 * This article, Misogynist_Acid_attacks, was created, but then had a speedy deletion tag placed on it, then moved from Misogynist_Acid_attacks to Acid attack and slightly expanded. I think you should be able to see the article under Acid attack now.  I think the name Misogynist attacks is more suitable than Misogynist_Acid_attacks or Acid attack, because there are similar attacks in those parts of Asia where burning or scalding oil or water are used or women set on fire instead.  However, these attacks are not necessarily committed by true misogynists, which are chronic general woman-haters, but men who felt jilted by a certain woman or situation at one time.  I don't know what a better name would be.  Nevertheless, this topic is important enough to have its own article in Wikipedia.  H Padleckas 04:09, 29 Apr 2005 (UTC)

Getting off on the wrong foot
I've removed the picture of the shoes.

Yes, it's a picture, and everybody loves pictures.

Yes, I'll even grant you that the shoes are leather.

Of course, hydrochloric acid may very well have been used in their manufacturing.

It's still utterly, completely, and totally devoid of any information whatsoever, and it annoys me. Apt pictures of how HCl is used are acceptable (though I'm not sure the gelatin picture is it) but throwing in leather shoes because HCl is used in leather processing is just silly. You wouldn't mention them in prose, so don't mention them in pictures. Why not add Fonzie's jacket, then? JRM 18:12, 2005 Apr 25 (UTC)
 * Yay! Support you 100% JRM. I hated the shoes. --jag123 02:10, 26 Apr 2005 (UTC)


 * Hmm, perhaps a picture of hydrochloric acid being added to leather, or something? -- Natalinasmpf 13:25, 26 Apr 2005 (UTC)

I put the shoes picture in the Wikipedia article Shoe and in Wiktionary under "Shoe" again, so such pictures often can be used somewhere. H Padleckas 18:15, 13 Jun 2005 (UTC)


 * I support this, too. However, I really would like to see the acid in action. HereToHelp 20:33, 28 September 2005 (UTC)

Biological section too long
Again the biological section has grown into a too long text, including details that should better be on a dedicated place for it. Could please a biologist take the recommendations from the very useful peer review (link see on top of this discussion page) and reduce that section by half or so? Wim van Dorst 05:10, 2005 May 9 (UTC).
 * Done. Article is now again below the official 30k limit. Please do not re-add the information: this is readily available for the interested reader in the wikilinked subjects in the remaining paragraph. Wim van Dorst 21:28, 28 July 2005 (UTC).

What is the pH of Hydrochloric acid?
I couldn't find it in the article.


 * Like any other acid, the pH depends on the concentration. It can be anywhere from 7 to -2 or so. --Carnildo 21:19, 8 Apr 2005 (UTC)
 * For the common concentrations, it is in the table now. Obviously, if you dilute it more, pH increase up to (max) 7. Lowest is about -1.1, as shown in the table. Wim van Dorst 22:15, 2005 Apr 8 (UTC).

For every tenfold dilution the pH goes up by 1 pH unit until you come close to pH 7. Cacycle 22:54, 8 Apr 2005 (UTC)

What about pure HCl?

Does not have a pH at all. Cacycle 08:55, 9 Apr 2005 (UTC)

i.e., if you have pure hydrogen chloride gas, there is no water, and the definition of pH requires water. If you mean what is the pKa, I see that the hydrogen chloride page lists this as -4. Walkerma 21:46, 9 Apr 2005 (UTC)

Doesn't acid need to be aqueous to be, well acidic, anyway? Isn't HCl in non aqueous form, well, non-reactive? Hydrogen chloride? -- Natalinasmpf 06:01, 25 Apr 2005 (UTC)

Yes, it does need to be aqueous to have a pH, per the definition of the pH. But HCl in pure form is also very reactive. Wim van Dorst 12:35, 2005 Apr 25 (UTC).

Yes, but that only happens when its mixed with organic material, because they organic molecules are bound to contain oxygen and hydrogen to create an immediate ionisation effect - forming the same negative chlorine ion and the positive ion of the other side of the molecule. Which is the key to hydrochloric acid's corrosiveness. Hydrogen chloride won't corrode metals by itself, unless you decided to add some sort of organic/water molecule to it. Which is the key difference with the disassociation effect, thus has less oppurtunies to corrode. Because from what I see, hydrogen chloride only reacts when it reacts with an organic molecule/water and becomes hydrochloric acid; it has to make that transformation. It still isn't corrosive by itself. -- Natalinasmpf 18:28, 26 Apr 2005 (UTC)

Okay, you guys have me confused. I recently took a chemistry class at one of the top colleges in the United States. There, we supposedly had and worked with "pure molar" Hydrochloric Acid, listed at somewhere around 16. Obviously, if Hydrochloric Acid is a solution and therefore a homogenous mixture in a water solvent, it could not be listed as pure from a molar aspect. However, we were never given a pH, and the molar scale is generally considered more accurate. Can anyone help me out with my confusion?207.118.41.6 06:06, 20 May 2007 (UTC)


 * There is no such thing as "pure molar" hydrochloric acid. 100% (anhydrous) "hydrochloric acid" is actually hydrogen chloride gas, a distinct chemical.  The dissolution of hydrogen chloride in water produces hydrochloric acid, in the same manner that the dissolution of sodium chloride in water produces salt water.  Hydrochloric acid is typically stored at a maximum concentration of about 38% (w/v), as it isn't very stable above that concentration (too much of it vaporizes to make it practical or safe for use).  Acid solutions aren't typically measured by pH, because it is not nearly as accurate or easy to measure as other units (mass and volume for molarity).  However, as a reference, 3.647% (w/v) or 1M hydrochloric acid has a pH of 0.0.  Remember that "pure" can just as easily imply "free of contaminants" as it can "100%" - as to why your professors or TAs chose to label something as "pure molar," I am unsure, because it should have been labeled with a quantitative value for molarity or w/v percentage.  Hope this helps! Dcteas17 06:52, 20 May 2007 (UTC)

It did help as much as the Wikipedia article, which is what gave me this confusion in the first place. :) The bottle was labeled ~16M, and the term "pure molar Hydrochloric Acid" is a direct quote from the professor. 16*3.647=58.352, so perhaps this was a maximum saturation of HCl in H2O?69.29.209.192 07:03, 23 May 2007 (UTC)

I'm having trouble with two phrases in this section: "i.e., if you have pure hydrogen chloride gas, there is no water, and the definition of pH requires water" and "Yes, it does need to be aqueous to have a pH, per the definition of the pH". I only know this definition of pH: the cologarithm of the activity of dissolved hydrogen ions. In this definition, water is not mentioned. So you can also determine pH in organic solvents and -in a total theoretical way- in any "solvent". I was just wondering because I often make solutions in organic solvents. I am wrong in saying that for example a solution of HCl in methanol has a pH? Ikbentbeu (talk) 12:35, 24 April 2009 (UTC)
 * The definition of pH requires a solvent, which usually is water. But there is a pH in other solvents too, although you shouldn't expect the neutral value to be '7'.  Wim van Dorst  (talk)  20:55, 24 April 2009 (UTC).

tables and infobox
well done. 141.213.129.41 02:30, 25 Apr 2005 (UTC) the pH is around 2, making it a strong acid. it is found in the stomach, where it catalyses the action of pepsin on proteins, but also kills bacteria.

As Weapon of Misogynists
Hydrochloric Acid is used in South Asia for domestic use, largely as a toilet cleaner. But another use is by men attacking women in a phenomenon that cuts across the boundaries of India and Pakistan, and while other acids are also used, HCl is the preferred weapon. 99% of attacks are by men on women, though there are some by women on men. This is an issue that needs to be addressed. Is this the correct place?

http://www.womensenews.org/article.cfm/dyn/aid/1908/context/archive http://ww1.mid-day.com/news/city/2005/april/107660.htm


 * I think there should be a separate article on Misogynist attacks in Asia. Anyone who has Internet access can write such an article.  For example, if you are in Wikipedia now and you see the red lettering in Misogynist attacks, you can simply put your mouse pointer on the red lettering and click, and a page will appear where you can start writing such an article.  If somebody else starts writing such an article and the link becomes blue (from red), you can still edit the article that was started, giving more information.  It would be a good idea to log in under a registered User (member) name when writing the article, but it is not necessary.  Also, if you think the article should have a different title, then you can start one with a different title by searching for the alternate title in the margin to the left of this page.  If an article with that title is not found, you can start a new one.  H Padleckas 17:00, 25 Apr 2005 (UTC)


 * Have done it as "Misogynist_Acid_attacks", but perhaps it is not yet uploaded? I am getting this message: "If you have created this page in the past few minutes and it has not yet appeared, it may not be visible due to a delay in updating the database. Please wait and check again later before attempting to recreate the page."

The article seems not to exist, unfortunately. However, you should wait for let's say two days before recreating it as I have had such problems too and the article appeared only after about a day. --Eleassar777 16:04, 28 Apr 2005 (UTC)


 * This article, Misogynist_Acid_attacks, was created, but then had a speedy deletion tag placed on it, then moved from Misogynist_Acid_attacks to Acid attack and slightly expanded. I think you should be able to see the article under Acid attack now.  I think the name Misogynist attacks is more suitable than Misogynist_Acid_attacks or Acid attack, because there are similar attacks in those parts of Asia where burning or scalding oil or water are used or women set on fire instead.  However, these attacks are not necessarily committed by true misogynists, which are chronic general woman-haters, but men who felt jilted by a certain woman or situation at one time.  I don't know what a better name would be.  Nevertheless, this topic is important enough to have its own article in Wikipedia.  H Padleckas 04:09, 29 Apr 2005 (UTC)

Getting off on the wrong foot
I've removed the picture of the shoes.

Yes, it's a picture, and everybody loves pictures.

Yes, I'll even grant you that the shoes are leather.

Of course, hydrochloric acid may very well have been used in their manufacturing.

It's still utterly, completely, and totally devoid of any information whatsoever, and it annoys me. Apt pictures of how HCl is used are acceptable (though I'm not sure the gelatin picture is it) but throwing in leather shoes because HCl is used in leather processing is just silly. You wouldn't mention them in prose, so don't mention them in pictures. Why not add Fonzie's jacket, then? JRM 18:12, 2005 Apr 25 (UTC)
 * Yay! Support you 100% JRM. I hated the shoes. --jag123 02:10, 26 Apr 2005 (UTC)


 * Hmm, perhaps a picture of hydrochloric acid being added to leather, or something? -- Natalinasmpf 13:25, 26 Apr 2005 (UTC)

I put the shoes picture in the Wikipedia article Shoe and in Wiktionary under "Shoe" again, so such pictures often can be used somewhere. H Padleckas 18:15, 13 Jun 2005 (UTC)


 * I support this, too. However, I really would like to see the acid in action. HereToHelp 20:33, 28 September 2005 (UTC)

Biological section too long
Again the biological section has grown into a too long text, including details that should better be on a dedicated place for it. Could please a biologist take the recommendations from the very useful peer review (link see on top of this discussion page) and reduce that section by half or so? Wim van Dorst 05:10, 2005 May 9 (UTC).
 * Done. Article is now again below the official 30k limit. Please do not re-add the information: this is readily available for the interested reader in the wikilinked subjects in the remaining paragraph. Wim van Dorst 21:28, 28 July 2005 (UTC).

Referencing
Is it appropriate to include non-open sources (i.e., Akzo Nobel technical papers) in the reference section? I think it is taken as read (or at least hoped) that editors use their personal knowledge when writing articles! Physchim62 21:16, 12 Jun 2005 (UTC)


 * I think it is appropriate, bearing in mind that there was extensive use made of these technical papers. Also, if something was important enough, it might well be possible to produce these documents- they are not like govt. security secrets.  I'm sure our page doesn't contain any proprietary information. Walkerma 23:33, 12 Jun 2005 (UTC)


 * As indeed a lot of information in this wikipage is based on detailed information from those non-open sources, I intentionally made it as explicit as possible, i.e., put up full reference details. And I can confirm Martin's certainty that, although those documents do contain proprietary information and therefore are non-open, no proprietary info was transferred into the hydrochloric acid wikipage. So Wikipedia is doing the proper thing. And I checked with my Akzo Nobel lawyers about the Akzo Nobel side of doing it like this. Overall, it was done intentionally, and I think it appropriate. Wim van Dorst 20:51, 2005 Jun 13 (UTC).

Hydrochloric acid in action
I think that a good addition to this article would be a picture of Hydrochloric acid actively eating away at something. I think such a picture is conspicuously absent from the article. However, if has too much shock value, don't post it.--HereToHelp|talk 12:50, 12 November 2005 (UTC)
 * Hydrochloric acid eating away on a piece of metal or so would be booooooring. It isn't really such an active acid as some think: you can actually wash your hands with rust in it (and rinse off quickly, of course). The most atrocious it can do would be to create a bit of rust or so, and ages later dissolve it. If you put very highly concentrated hydrochloric acid on marmer it bubbles a bit (better results with sulphuric acid, school teacher experience here). And a rusty pipe or bubbly beaker wouldn't be an augmentation of the article, in my opinion. If you have a better picture, feel free to propose it (as in adding it). Wim van Dorst 20:34, 12 November 2005 (UTC).
 * Actually I think there are some possible reactions of HCl, for example with a more active metal that forms coloured ions (Neodymium or Raney nickel come to mind, but I don't have Nd metal). The other possibility is an oxidation reaction that produces chlorine. I'll try to come up with something. It would certainly emphasise the acidic nature of HCl.  Walkerma 21:27, 12 November 2005 (UTC)
 * Wouldn't it over-suggest acidity? It is actually pretty harmless, as acids go. But I'm a sucker for nice pictures, so give it a go. Wim van Dorst 21:42, 12 November 2005 (UTC).
 * What about HCl with aluminium, not coloured but at least it's something everyday folk are familiar with? I know it reacts nicely after the induction period is over. Walkerma 21:51, 12 November 2005 (UTC) By the way, let's not forget about Image:Hydrochloric acid ammonia.jpg which I think is fun. This is on the ammonium page.
 * Good idea: this reaction will definitely appeal to a wider audience, especially if we refer it to salmiak. It is a treat in the US too? The picture isn't really nice, though, but will make do, I guess. Wim van Dorst 22:20, 12 November 2005 (UTC).
 * I commonly use Hydrogen Peroxide to oxidize copper and then add hydrochloric acid to create Copper Chloride... Works quite well, and bubbles a lot. Not to mention you end up with a lot of hydrogen and a low-heat firework colorant :D 67.42.76.182 14:59, 18 October 2006 (UTC)

what would happen if you combined hydrochloric acid to marble chips or little pieces of stone? —Preceding unsigned comment added by 216.8.145.93 (talk) 21:55, 21 October 2007 (UTC)
 * Actually, not much. I tried various concentrated acids for a demonstration in a schoolroom class, and found that only sulfuric acid did anything to marble chips: it makes bubbles (the chemistry is easy). I'm sorry to say that even concentrated hydrochloric acid didn't make a visible impact during the time span of one lecture. Wim van Dorst (Talk)'' 22:12, 21 October 2007 (UTC).
 * Aluminium foil and concentrated (33%) hydrochloric acid react very fast.

Is the ASREC regeneration process text blatant commerce or good tech info?
The text as has recently been added by unnamed IP-numbers about spent acid regeneration process is, in my humble opinion, getting to be blunt commercial advertisements instead of good technical information. Anyone knowledgeable in this field willing to copy-edit that section? Wim van Dorst 22:17, 15 December 2005 (UTC).

Reaction with sugars when introduced to heat
I heard that when sugars added to HCL, and then heat is applide, the subtstance will combust. Can anyone confirm this? - J e d O s  21:53, 20 December 2005 (UTC)
 * It doesn't. Hydrochloric acid is not an oxidizing acid. Other than the weak H+ proton, there is no oxidizing acid to it. Use chloric acid if you want a flame. --Chemicalinterest (talk) 00:33, 8 September 2010 (UTC)

Bayer product link
Is the recently added link to product info (skimpy imho) of very minor player Bayer (do they produce or only refine?) a worthwhile addition to the article? Wim van Dorst 21:21, 26 January 2006 (UTC).
 * As our resident industrial HCl expert, I'd trust your opinion. I would take the view that if they are a manufacturer of significance (>1% worldwide or >5% in the particular country) then the link should stay.  If they are a major supplier but not an actual manufacturer, I would suggest we need a separate heading for suppliers.  If they are neither, and they don't have an important and unique niche (e.g. high purity for electronics or something), let's delete the link. Walkerma 17:03, 27 January 2006 (UTC)

Possible cleanup needed?
Anyone else see it - there is a lot of information from the info table repeated in the article, are these both required or can we settle for one or the other?

Ryan Jones 00:25, 17 March 2006 (UTC)


 * This can be a problem, particularly in long articles. I suspect (no evidence to support this though!) that this probably very slowly increases over time, so maybe 1 year after FA we should review this.  However I think it's often useful to include the data in the text if they are central to the flow of the article.  Can you perhaps list the offending sections of text so we can review them one by one?  A bigger problem, IMHO, is the fact that the supplementary data page is largely empty at present (this approach was created after this became FA), we need to fill in the data. Thanks, Walkerma 04:21, 17 March 2006 (UTC)


 * Ryan Jones: Here are the one I see right off:
 * * Safety - S-phrases already in info table, repeated?
 * Thats about the only big one I can find.
 * Ryan Jones 12:14, 17 March 2006 (UTC)

The listing of the R- and S-phrases is indeed double. It is such a nice table, though, that you'd have to be a butcher to rip it out. The table was created well before the nice templates such were developed by PC, so the table is indeed mostly here for historical reason. Oh, well, if we can't find any other argument than that: sentiment shouldn't hamper progress: out it goes. Wim van Dorst (Talk)'' 16:07, 19 March 2006 (UTC).

Notable revertion
Yesterday, the following text was added to the Hydrochloric acid article:
 * Hydrochloric acid was mentioned on page 7 (third column) of the March, 2006 issue of Chemistry World, a publication of the Royal Society of Chemistry, along with a comment on the speed with which vandalism is removed from chemistry articles in Wikipedia.

It took exactly 72 seconds for this addition to be reverted. QED. This really makes me smile. Wim van Dorst (Talk)'' 15:35, 1 April 2006 (UTC).


 * Actually, Wim, I think it took 72 minutes, and our usual vandalism traps missed it because it was (a) reasonable-sounding rather than obscenities or blanking, (b) the edit occurred when Europeans are asleep and (c) the user gave an edit description, something vandals rarely do. But then again, on April Fool's Day we could allow a little humour on the chemistry pages!  Walkerma 01:46, 2 April 2006 (UTC)

Nantionality of jabir ibn hayyan
A quick look in Britannica or Columbia Encyclopedia , and all major Encyclopedia's would tell you that he is an Arab not Iranian. Jidan 14:47, 4 April 2006 (UTC)


 * There are conflicting sources about his ethnicity, but he's defiantly Iranian-born as per your own sources plus the evidence and discussions on Talk:Geber. --ManiF 14:51, 4 April 2006 (UTC)

Peerreviewer output
The following suggestions were generated by a semi-automatic javascript program, and may or may not be accurate for the article in question.

You may wish to browse through User:AndyZ/Suggestions (and the javascript checklist; see the last paragraph in the lead) for further ideas. Thanks, Wim van Dorst (Talk)'' 20:01, 26 June 2006 (UTC)
 * Please ensure that the article has gone through a thorough copyediting so that the it exemplifies some of Wikipedia's best work. See also User:Tony1/How to satisfy Criterion 2a.

HCl + Al > ?
What are the substances that are produced? --Kalmia 08:12, 25 October 2006 (UTC)
 * 6 HCl + 2 Al → 3 H2 (g) + 2 AlCl3 (aq). If this occurs while unloading hydrochloric acid into a aluminium tank (stupid, stupid, but it happens), and if you're not careful the hydrogen ignites from a spark of the truck: Boom! Wim van Dorst (Talk)'' 21:49, 27 October 2006 (UTC).
 * Maybe I'll get a picture of the two togethor. --Kalmia 14:24, 5 December 2006 (UTC)
 * Aluminium foil works well. --Chemicalinterest (talk) 00:31, 8 September 2010 (UTC)

pKa
This article states the pKa as -8. The Wikipedia article on acid states that the Ka of HCl is is 10^7, therefore the pKa = -7. Fundamentals of Organic Chemistry, an organic chemistry textbook from 1990, says it is -7. I edited this article to agree with the latter two sources.

After having my edit reverted, I looked a little further and it seems that the pKa of HCl and other strong acids is not so clear cut. Atleast according to chembuddy.com the pKa of strong acids is usualy not measured, rather it is calculated based on thermodynamic data. Perhaps depending on the thermodynamic data used, or the model/equation, you can get a different answer. Or maybe this is a rounding issue.-Boonukem


 * Indeed the pKa of strong acids are difficult to determine. It highly depends on numerous other circumstances than just acidity. Therefore most often these values are merely listed as '< 0'. For hydrochloric acid, it also depends highly on the concentration of it. And given a typical concentrated acid at 37%, the pKa then is -8. See also the table in paragraph 2 for physical properties to see how physical properties (notably pH of course) changes with concentration. I propose that in this article the -8 value stands. Wim van Dorst (Talk)'' 22:42, 7 November 2006 (UTC).

Is the Acid-to-Water rule valid for Hydrochloric Acid?
water should never be added to the concentrated acid, as this releases enough energy to make the water boil and splatter acid; rather, acid should be added to water

I understood that this rule was for Sulphuric acid. I didn't think it applied to Hydrochloric acid, and I've not noticed a strong heating effect when diluting it. Anyway, even concentrated HCL is already about 65% water.

It goes on to say See references for details, but doesn't link to a specific reference.

Royhills 17:39, 7 April 2007 (UTC)


 * The caution isn't wrong per se, but it is indeed too strict. As written, it applies, as you expected, to sulfuric instead of hydrochloric acid. But don't think that the really concentrated hydrochloric acid (>36 up to 40%) might not be dangerous: always do dilution by adding the acid to water, which ever acid, even acetic acid: that is what safe chemistry is about.
 * Nonetheless, I toned down the paragraph to give more appropriate information. This was a late addition that I had missed. Thanks for pointing out this Opportunity for Improvement. Wim van Dorst (Talk)'' 21:55, 7 April 2007 (UTC)

Muriatic Acid
Doesn't Muriatic Acid contain Zinc Chloride? I thought it did when used for cleaning surfaces to be soldered. Anybody?
 * No, muriatic acid (hydrochloric acid) is a pure chemical compound, which does not contain impurities. For soldering, btw, I seem to recall that sulfuric acid is being used instead of hydrochloric acid. And from the welding material it may pick up some metal, converting it to zinc sulfate (not chloride of course). Was this what you're thinking of? Wim van Dorst (Talk)'' 19:38, 1 June 2007 (UTC).
 * It will if you dissolve zinc in it. --Chemicalinterest (talk) 00:31, 8 September 2010 (UTC)

References?
For a featured article, this article has a suprising lack of references. This needs to be addressed for the article to keep it's FA status. --203.30.68.49 04:48, 17 September 2007 (UTC)
 * don't whine or threat: this article had featured status way before most current editors even started using wikipedia! Do something positive and add useful references. Wim van Dorst (Talk)'' 22:46, 19 October 2007 (UTC).

Density?
What's the density of 1.0 M hydrochloric acid? --71.142.86.100 03:25, 6 October 2007 (UTC)
 * About 1.02. Read the table of physical properties. A 1M solution is very dilute. Wim van Dorst (Talk)'' 22:55, 19 October 2007 (UTC).

chembox vs new chembox
Today, I have reverted the introduction of the new chembox (by Rifleman), mostly that edit removed a lot of significant information. That the Hydrochloric acid article has been the original of the chembox in the WP:Chem is just n history trivia that should be remembered, but may not be blocking a future introduction of a complete new chembox. Wim van Dorst (Talk)'' 20:48, 17 October 2007 (UTC).


 * I've checked manually and I think it's been fixed. Edgar's also helped fix some of the tables the script attacked. Do take a look? Sorry for the trouble earlier. --Rifleman 82 13:59, 18 October 2007 (UTC)
 * Yep, this looks like a good one. I won't revert this anymore, although being a historic kind of guy I'm sorry to see the good old-fashioned table chembox go, even here in the hydrochloric acid chembox birthplace article. I did re-introduce the major producer information and other external links: these have been IIRC subject of high debates, and IMHO fortunately the decision for 'major producer links' was keep. Thanks for the good work. Wim van Dorst (Talk)'' 22:42, 19 October 2007 (UTC).

Solid-liquid phase diagram


Unfortunately the article is protected. I like to add the graph of the solid-liquid phase diagram which describe the melting behaviour in dependence on concentration. --Steffen 962 (talk) 18:03, 13 November 2009 (UTC)
 * Added. Thank you. Could you please add the source of the data on that graph, to the image file or here. Materialscientist (talk) 23:37, 13 November 2009 (UTC)
 * The graph based on data from the German books Gmelins Handbuch der Anorganischen Chemie, Systemnummer 6 Chlor, Verlag Chemie Berlin 1927 and Gmelins Handbuch der Anorganischen Chemie, Systemnummer 6 Chlor, Ergänzungsband Teil B - Lieferung 1, Verlag Chemie Weinheim 1968. Since 1990 the Gmelin was published as Gmelin Handbook of Inorganic and Organometallic Chemistry.--Steffen 962 (talk) 00:05, 16 November 2009 (UTC)

jabir/geber
I removed this The alchemist Jabir ibn Hayyan first formally described it in the eighth century. because as can be seen by the source cited The historical background of chemistry Henry Marshall Leicester. Hydrochloric acid is not formally described until Libavius in the 16th century. This is confirmed by all reliable sources. There is a great deal of wp:or original research in wikipedia on the the works of Jabir. Some of it is is just a reflection of confusion over the identity of the 8th century Jabir with the 13th century Pseudo Geber (as in the case of sulphuric acid) however it is hard to assume good faith in a case like this.J8079s (talk) 23:45, 16 November 2009 (UTC)

Mistake: Production of organic compounds
"2 CH2=CH2 + 4 HCl + O2 → 2 ClCH2CH2Cl + 2 H2O (vinyl chloride by oxychlorination) "

This outlines the synthesis of ethylene dichloride (sym-dichloroethane) via hydrogen chloride, not the synthesis of vinyl chloride. Additionally, I think the synthesis of sym-dichloroethane via HCl is more suitable to the hydrogen chloride wiki as, if I understand the process correctly, the HCl used should be appreciably water free. —Preceding unsigned comment added by 69.182.43.154 (talk) 03:24, 7 January 2010 (UTC)
 * Thank you. I corrected the text, but don't understand your second remark. Materialscientist (talk) 03:34, 7 January 2010 (UTC)


 * The production of sym-dichloroethane is a vapour phase process using HCl(g) not HCl(aq) therefore, the synthesis is unsuitible for the hydrochloric acid article, it should instead be moved to the hydrogen chloride article. —Preceding unsigned comment added by 69.182.43.154 (talk) 03:38, 7 January 2010 (UTC)
 * Thank you. Would it be right to say that hydrochloric acid is used as initial reagent, but is vaporized in the process?

Materialscientist (talk) 03:48, 7 January 2010 (UTC)
 * Probably not. From an industrial point of view, the purpose of oxychlorinations is to take waste HCl (which is less valuable industrially than Cl2) and convert it mid process into Cl2, allowing it to be used in chlorinations.  The sources of this waste HCl are generally radical chlorinations or a dehydrochlornations.  In the specific example, most sym-dichloroethane is converted to vinyl chloride producing HCl as a byproduct:


 * C2H4Cl2(g) -heat-> C2H3Cl(g) + HCl(g)


 * Therefore half of the HCl used in the synthesis of vinyl chloride will come from this appreciably anhydrous waste HCl. The other half could come from another process. The point is, no plant in their right mind would only make HCl or buy Hydrochloric acid and convert it to HCl for an oxychlorination.  Industrial plants are made such that any processes that produce HCl are coupled to oxychlorinations so none of the starting Cl2 is wasted.  The types industiral processes that produce HCl are Aromatic chlorinations, radical chlorinations, and dehydrochlorinations, all of these reactions produce appreciably anhydrous HCl as a byproduct.  If you are further interested in this type of chemistry I encourage you to flip through "Ethylene and its Industrial Derivatives" by Miller.

Liquid-vapour phase diagram


Additionally to the solid-liquid phase diagram of HCl-water mixtures I have constructed the liquid-vapour phase diagram. I like to add this graph which describe the boiling behaviour and azeotrop formation in dependence on concentration.--Steffen 962 (talk) 22:04, 25 January 2010 (UTC)
 * We need to explain the two branches there. Materialscientist (talk) 06:26, 27 January 2010 (UTC)

Hydrochloric Acid manufacturers
FMC is mentionned as being one of the manfacturers of HCl. I don't believe this is the case. Furthermore the FMC link is for Formasa Plastics, which is different company altogether. —Preceding unsigned comment added by Lamarcheb (talk • contribs) 19:34, 1 June 2010 (UTC)
 * Oh, yes, it is really FMC. That not doubtful. But the link is wrong, it should be FMC Corporation. Thanks for pointing out this opportunity for improvement.  Wim van Dorst  (talk)  21:04, 22 June 2010 (UTC).

The discovery of Hydrochloric acid
Well, the history section of this article is really a mess. Let´s begin by the beginning: Jabir did not discover hydroclhoric acid. In fact he discovered few things. Sulphuric acid, nitric acid and aqua regia, attributed to him for centuries, were in fact discovered by Pseudo-Geber. The supposed experiment that Jabir used to discover this acid (mixing common salt with sulphuric acid) was in fact done by Basil Valentine in the 15th century. No proof Jabir was acquainted with this acid.

There´s a scholarly consensus that Hydrochloric acid was not discovered until the 15th or late 16th century. Not even Pseudo Geber discovered it. While it´s true that Aqua regia is a mixture of hydrochloric and nitric acids, he obtained it by disscolving salmiac (aka ammonium chloride) in nitric acid. So he didn´t know anything about hydrochloric acid. I´ll fix this confusion as soon as I can. Regards--Knight1993 (talk) 18:29, 20 June 2010 (UTC)
 * Hi Knight, that is all problably very true. I did have trouble finding good references for it, though. So, if you have a good reliable source of this information, please do edit the section accordingly.  Wim van Dorst  (talk)  20:59, 22 June 2010 (UTC).
 * Page 87 you can see a lot of the pages at google books (and search). "Forbes" has a good reputation. I'll look for some more Knight is going to need themJ8079s (talk) 02:56, 23 June 2010 (UTC)

The article on Mary The Jewess says that the claim that she discovered hydrochloric acid is in wide circulation, and certainly I remember this being taught to me at school. Would it not be a good idea to strengthen this section with an explicit rejection of (and link to) that claim and any others that have become popular? OldTownAdge (talk) 15:26, 27 July 2010 (UTC)
 * Thanks for spotting that one, OldTownAdge. I´ll try to correct that one too.--Knight1993 (talk) 18:12, 16 August 2010 (UTC)

New version of section

I have uploaded a new version of the history section, per a discussion that took place at talk:Chlorine. Please discuss any issues with the updated section here. Best regards, Polyamorph (talk) 07:26, 17 August 2010 (UTC)
 * First we need to add: Free hydrochloric acid is first formally described by Libavius in the 16th century. This is confirmed by all reliable sources see The historical background of chemistry  Henry Marshall Leicester. (I have others if needed). Second we need to add that hydrochloric acid occurs in nature Third you add: The discovery of Hydrochloric acid is sometimes, although most likely falsely, attributed to the alchemist Jābir ibn Hayyān, also known as Geber, in 800 AD. I would like this to say: The discovery of Hydrochloric acid was (and sometimes still is) falsely attributed to the alchemist "Geber" (in the Suma) who was (and sometimes still is) identified incorrectly as Jābir ibn Hayyān (c.800 AD). My sources for this:  "Mr. Thompson also credits the Arabian Geber with knowledge of nitric acid, nitrate of silver and hydrochloric acid, as described in the Summa Perfectionis and Liber Philisophorum [sic], whereas Berthelot showed in 1893 that these Latin treatises are fraudulently ascribed to Geber, who had no knowledge of the mineral acids." Holmyard held out against Berthelot but but says in a foot note that he is "nearly alone" in doing so and that the people he was disagreeing with were better qualified than he was. (Holmyard, Eric John (1931). Makers of Chemistry, by Eric John Holmyard, Clarendon press.  Holmyard did his home work and in wrote Alchemy. Courier Dover Publications. p. 134. ISBN 9780486262987.  1957 Holmyard had abandoned the idea that "Geber" was "Jabir" J8079s (talk) 20:50, 18 August 2010 (UTC)
 * I agree with ordering the paragraph in the way you describe (i.e. state the first formal description first and mention the false attribution to Jabir afterwards) and I agree to the changes to the text that you have proposed. Feel free to edit the article accordingly. Polyamorph (talk) 10:49, 19 August 2010 (UTC)
 * I'm sure we can work together on this. I may have scrambled the refs a bit. I think we may need some kind of foot note or something to show which shows whatJ8079s (talk) 21:58, 19 August 2010 (UTC)


 * The source of this content ...According to some authors, free hydrochloric acid was first formally described in the early 16th century by Libavius... don't show that Libavius described this acid in the early of 16th century, while he was born in 1555. And his book was published in 1611-1613 (early 17th) mentioned clearly about this preparation. --Tranletuhan (talk) 15:16, 16 September 2010 (UTC)

Misguided article
There is a significant problem with this article as it stands now, namely, that it treats "hydrochloric acid" as if it were a pure compound. There's an infobox with a molar mass, a molecular formula--and yet no such compound exists. Solutions of hydrogen chloride do not contain discrete hydronium-chloride ion associations, so I am not at all clear what the meaning, if any, of a molar mass or molecular formula is in this context.

I can tell you that anyone who comes to this article looking for a molar mass is looking for the molar mass of hydrogen chloride. Together with the strength (in weight percent) of the acid they are using, they can calculate whatever it is they are after. Currently, though, the "molar mass" of hydronium chloride serves only to confuse. The highest commercially available concentrations of hydrochloric acid are in the vicinity of 38%--hence, even in "concentrated" hydrochloric acid, the molar mass stated in this article is irrelevant.

Clearly, one can make compelling arguments for separating hydrogen chloride and hydrochloric acid into two articles. However, I can see no justifiable reason for treating the hydrochloric acid article as if it were about a pure compound. The (almost entirely empty) infobox should be deleted. -75.150.254.105 (talk) 18:23, 5 April 2011 (UTC)
 * Much ado about nothing (molar mass - fixed). For more details see this. Materialscientist (talk) 00:22, 6 April 2011 (UTC)

Units
Yes, the SI units are the Kg and meter, etc...  But chemists use the cgs system. I have never seen a chemistry book give a concentration in Kg/m^3. Perhaps that's because m^3 flasks are somewhat rare in the average chem lab. If you are going to give the density as Kg/l, then why give the molarity in moles/dm^3 ??? At least be consistent ! Since this is an article about chemistry, why not use the chemist's cgs system. Save the mks for physics. — Preceding unsigned comment added by 50.41.15.172 (talk) 05:29, 25 June 2011 (UTC)

How is this a feautred article about a chemical and there's not even the molecular weight???
36.46 g/mol

Please add it to the page. — Preceding unsigned comment added by Smit1442 (talk • contribs) 16:57, 14 July 2011 (UTC)
 * Hydrochloric acid is a solution of hydrogen chloride (HCl) in water, it has no fixed molecular weight, you're referring to hydrogen chloride. Materialscientist (talk) 22:44, 14 July 2011 (UTC)

edits to a semi-protected page by proposing them on its talk page
"protected by a [...] protective mucous layer" sounds strange. 95.115.67.211 (talk) 16:38, 22 March 2012 (UTC)


 * ✅ - removed the word "protective" that preceded "mucous layer". Polyamorph (talk) 16:42, 22 March 2012 (UTC)

Merge
Consider a merging of this article into the Hydrogen Chloride article under a Hydrochloric acid heading?-- Gilderien Talk|Contribs 11:41, 9 April 2012 (UTC)

CAS-Number
Hi, I was wondering, why there isn't any CAS-number listet in this article. Sigma Aldrich says 7647-01-0 (http://www.sigmaaldrich.com/catalog/search?interface=CAS%20No.&term=7647-01-0&lang=en&region=SE&focus=product&N=0+220003048+219853235+219853286&mode=match%20partialmax), the German wikipedia (http://de.wikipedia.org/wiki/Salzs%C3%A4ure), too. Should it be added? 130.235.227.90 (talk) 10:33, 19 September 2012 (UTC)
 * That is the CAS number of hydrogen chloride, not hydrochloric acid. Plasmic Physics (talk) 10:54, 19 September 2012 (UTC)

If you know it, then please what is the CAS number of hydrochloric acid? 130.235.227.90 (talk) 11:03, 19 September 2012 (UTC)

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