Talk:Nitric acid/Archive 1

Corrosive hazard
I don't understand the comments about yellow/orange stains: doesn't this acid actually burn skin and corrode it, rather than stain it??? This needs to be clarified, because as written, the article is self-contradicting. Nyh 09:02, 31 Mar 2004 (UTC)


 * From my experience, the acid burns and stains the skin, and the stain persists long after the burn is healed. Additionally, concentrations that are generally too dilute to burn the skin do result in yellow stains. Gentgeen 14:07, 31 Mar 2004 (UTC)


 * ADDENDUM-I found an MSDS here that lists under potential health effects, Skin Contact: Corrosive! Can cause redness, pain, and severe skin burns. Concentrated solutions cause deep ulcers and stain skin a yellow or yellow-brown color. Gentgeen 16:56, 31 Mar 2004 (UTC)

How long does the staining last for? Should I be worried about anything more than cosmetics? 169.237.44.114 21:35, 21 February 2006 (UTC)
 * For "normal" cases, those in which there is no actual chemical burn, the stain lasts for five to seven days. It is caused by the oxidation of tyrosine residues in the proteins which make up the epidermis&mdash;the same reaction which causes cut apples to turn brown&mdash;and so lasts until that layer of the epidermis is shed naturally. The stained epidermis tends to disappear faster than unstained epidermis, but it is rarely so fast as to cause sensitivity or the underlying skin. Minor staining of the fingers is considered inocuous. I tell my students to go and see their doctor if they are worried, as medical students do some chemistry during their studies (and they're not usually the best) and so many doctors have personal experience of minor nitric acid stains (I explain the second part as well). To my knowledge, not one student has yet bothered! Physchim62 (talk) 22:26, 21 February 2006 (UTC)

Molar mass
What is that "g" after the digit 9 in the molar mass 63.0129g g/mol? Was it a typing error? sentausa 18:02, 9 March 2006 (UTC)
 * Almost certainly, yes, or a copy-and-paste edit. I've removed it now, and rounded the figure to the first two decimal places (as is usual for general-purpose molar masses). Physchim62 (talk) 17:42, 10 March 2006 (UTC)

pKa
I'm confused with the pKa of nitric.


 * -1.3 here


 * -1.44 here


 * -1.5 here

And I can't find where there has the value -2.

Which one is true?
 * Any pKa which is so low is difficult (if not impossible) to measure accurately. I'm frankly amazed that you found three values so close, as I see have seen values as low as &minus;3! About &minus;1.5 seems reasonable given your sources; you won't find much better. Physchim62 (talk) 17:04, 18 January 2007 (UTC)

Is the relation of pKa to the actual Ka value goes like: pKa = -logKa ? Because I'm looking for an actual value of Ka not pKa. Therefore, I think that noting the Ka value of all chemicals in the article table is of some importance, no? 74.96.186.207 00:46, 21 January 2007 (UTC)
 * Actually, I found that doing pKa = -logKa on a pka value of negative (such as -2, -1.5 noted above) impossible. I am also looking for Ka and Kb values and support the fact that such values should be noted on the main article - Anonymous Chemist


 * Yes, it's the same as pH = -lg[H+]. Causesobad --> Talk) 13:13, 22 January 2007 (UTC)

formula
what is the formula for nitric acid in acid rain??? O~O —The preceding unsigned comment was added by 86.6.160.152 (talk) 16:01, 19 February 2007 (UTC).

what kind of chemical bond is nitric acid
Hello, I really need an answer to this question for a big school project I am doing. Is nitric acid an ionic or covalent bond? Respond ASAP. Thanx! 67.184.234.126 22:14, 14 May 2007 (UTC)

Making Nitric Acid
How to make 99% concentrated Nitric acid? —The preceding unsigned comment was added by 61.5.138.29 (talk) 12:09, 16 May 2007 (UTC).

Nitric acid's uses
One of nitric acid's uses is in acid rain? ==Uses== ... Nitric acid is a component of acid rain. ... Surely nitric acid isn't used in acid rain, unless it's in an obscure weapon?--Steven Weston 21:01, 9 May 2007 (UTC)

that'd be quite a weapon... just TRY and stop it... "its like trying to stop the seasons" ~ —Preceding unsigned comment added by 74.87.82.86 (talk) 06:34, 6 February 2008 (UTC)

Reaction with Keratin
At what concentration does Nitric Acid cause skin to turn yellow?
 * it is because the xantho proteins in the layer of skin reacts with the nitric acid to give xanthoprotic acid which is yellow —Preceding unsigned comment added by 59.92.169.20 (talk) 16:35, 25 March 2008 (UTC)

NFPA diamond
The NFPA symbol (i think thats the right terminology) is wrong. Health is 4 and reactivity is 3.
 * The values for the NFPA diamond come from the International Chemical Safety Card cited in the article. Physchim62 (talk) 09:49, 7 January 2006 (UTC)
 * I restored the diamond, using properties given for 70% nitric acid. --GCarty (talk) 08:36, 10 August 2008 (UTC)

Nitric acid properties
The properties of HNO3 are still too vague. Should we add some reactions as illustration for each property? Abelin  C A  usesobad  14:00, 20 December 2006 (UTC)

The boiling point of pure nitric acid is listed as 83 degrees Celsius. Where was that found? I have plenty of books listing the boiling point as 86 degrees Celsius. —Preceding unsigned comment added by 146.151.43.102 (talk) 19:53, 12 November 2007 (UTC)

Someone please reword "When boiling in light, even at room temperature..." : I have only a faint idea of wht was meant. 1. Boiling in light? Boiling exposed to light OR at room temperature? Vapors exposed to light? What? 2. Boiling at room temperature - what, reduced pressure? 3. DOES boiling have anything to do with the NOx formation (other than the temperature acceleration)? —Preceding unsigned comment added by 63.81.122.66 (talk) 16:21, 16 October 2008 (UTC)

Toxicity
It's said in the first few lines of the article that Nitric acid is highly toxic. The acid is indeed very dangerous as a highly corrosive acid and a strong oxidizing agent, but I don't think it's toxic. The nitrate cation appears almost everywhere in the organic world, nitrate salts are used as fertilizers as well, it can't be toxic, at least not highly toxic. -Zhieaanm 12:31, 22 November 2008 (UTC)

Cncentration of Nitric Acid
Can i concentrate the Nitric acid like H2S04? If not then how can concentrate the Nitric Acid? —The preceding unsigned comment was added by 193.251.135.126 (talk) 12:45, 28 January 2007 (UTC).


 * As the article states, you can concentrate nitric acid up to 68% by boiling. Norm Reitzel (talk) 13:43, 19 January 2009 (UTC)

Industrial Production
The paragraph on industrial production was cleaned up and citations added. The No Citations reference was removed. Question: Is it appropriate for me to remove this indication, or is there a more formal procedure to decide that citations are adequate? Norm Reitzel (talk) 13:47, 19 January 2009 (UTC)

Where is the high voltage spark process??
Wiki fails again. Birkeland-Eyde Process. http://www.backyardchem.com/nitric-acid.php —Preceding unsigned comment added by 69.152.173.159 (talk) 07:35, 8 May 2009 (UTC)


 * The arc process for producing nitric acid is hardly a backyard process. A lot of popular press makes it sound feasible for a tinkerer, but yields of nitric oxide under the best of conditions are only around 4%, and recovery of these nitrogen oxides into solution was the subject of intense research from the process introduction until it was supplanted by the Ostwald process.  Anyway, I've included a paragraph about the use of this process. Norm Reitzel (talk) 01:23, 12 August 2009 (UTC)

Muslim alchemist
Why is it important to state that he was Muslim instead of where he was from? Wouldn't Arab or Persian or Egyptian do? Does one call Archimedes a Pagan scientist, Einstein a Jewish scientist, Galileo a Christian scientist and Feynman an Atheist scientist? —Preceding unsigned comment added by 212.54.216.186 (talk) 15:49, 28 March 2008 (UTC)


 * Since he lived in the (Abbasid) Caliphate which viewed itself as the empire of Islam rather than as a nation-state, it could be argued that "Muslim" is the most appropriate demonym. Then again, maybe not - if he were Christian or Jewish then a reference by religion would be suboptimal, and calling him a "dhimmi alchemist" would be worse still. --GCarty (talk) 20:16, 15 August 2008 (UTC)


 * Moreover, at the time, the Christan world in Europe was undergoing a rather unfortunate episode in which the Holy Mother Church was the arbiter of all knowledge, and things were rather grim. In point of fact, the fact that the Islamic Caliphate encouraged inquiry into the physical world is germane to advancement of chemistry, and science as a whole. Norm Reitzel (talk) 15:35, 13 August 2009 (UTC)

Preparation
Hi guys, could you elaborate more on the first method of synthesis, where it says "by taking a **** on someones face"?

About the synthesis, it says to convert red to white by using reduced air pressure, giving the values of 27 KPa or 20 mmHg. These are diffrent values by a factor of ten; I'm going to assume it's the higher one (just my intuitive guess) and change it to 27Kpa and 200mmHg. I could be wrong though, does anyone know for sure?--2tothe4 01:29, 12 November 2005 (UTC)

Something else... the removal of the NO by reduced pressure makes sense, but wouldn't heating the acid have the same effect? Or would the HNO3 start to dissociate?--2tothe4 14:51, 12 November 2005 (UTC)
 * It does indeed dissociate as you heat it, defeating the purpose. On the other hand, there was talk of reducing the temperature of the reaction (from 90 C to 81-85 C) which would significantly reduce the amount of NO. --AK7 13:42, 24 November 2005 (UTC)

Doesnt sulfuric acid turn skin yellow as well?


 * No. If you leave it on skin long enough, it turns black and bubbles up like foam.  By that time, it's too late, and a trip to decontam and then a good physician is in order. Norm Reitzel (talk) 15:39, 13 August 2009 (UTC)

removal

 * "Nitric acid has the highest distinction (amongst all acids) of attacking and dissolving all metals on the periodic table except Gold and Platinum."

And tantalum, niobium - this at least needs clarifying. An "highest distinction" is a peacock term, and unsuitable.83.100.250.79 (talk) 16:08, 7 September 2009 (UTC)

add
You can add information that Polish sciencist invented method to get nitrous from air :) —Preceding unsigned comment added by 79.186.145.167 (talk) 20:44, 21 November 2007 (UTC)

Under the section on Culture, I think that the original Batman story of Two-face involved a lawyer who was splashed in the face with nitric acid. Unfortunately, I don't have a reference right now. BTW - the Ira Ramsen story of nitric acid is a personal favourite. Oliver —Preceding unsigned comment added by 207.210.34.14 (talk) 13:15, 7 October 2009 (UTC)

Definition of glacial
The intro says "Colorless when pure, and a slight yellow when glacial..." what does "glacial" mean in this context? Maybe this could be explained under the "Grades" heading? —Preceding unsigned comment added by Philwkpd (talk • contribs) 05:02, 25 August 2009 (UTC)

it means concentrated to the max posible —Preceding unsigned comment added by 129.96.152.50 (talk) 06:09, 14 September 2009 (UTC)

glacial nitric acid doesn't exist, it is only a valid term for acetic acid, someones making things up

It does exist, I use it in my labs regularly. —Preceding unsigned comment added by 129.96.197.174 (talk) 02:25, 9 October 2009 (UTC)

Nitric acid and Egyptians
I removed the statement about nitric acid being used by the ancient Egyptians; it seems dubious and is not backed up by a given external source. Can anyone find a source for that statement? Algebra 00:37, 6 December 2006 (UTC)

I believe that was referring to the nitric acid battery like pottery that some archaeologists found, they were filled with nitric acid I believe and had something like an iron pipe inside of another pipe, dipped in nitric acid inside of a jar, and sealed with a tar or resin like substance. more research is necessary, but I do believe that it was mentioned on an episode of myth busters awhile back, turned out to be a legitimate source of electricity and could provide enough voltage to be felt through one's skin....

There is an edge-of-archeology belief (almost UFOparanoids)that the Babylonians, not Egyptians were able to electroplate using the easier to make Sulfuric acid w/lead plates. First mention I can remember off-hand is Electronics Illustrated article of 1960s.

COULD the Babylonians have stumbled on weak sulfuric, yeh, and they had lead and left some peculiar pottery. Batteries?? electroplating... long stretch.

Am currently searching for legit aqua fortis info pre-Pyrotechnia (15th C., CE by which time it was common and produced on industrial scale. Theophilius does not mention it, but supposedly half-mystic Ramon Lull (inventor of various mnemonic memory systems and methods of receiving advice from Christian angels) and an uncorrupted ms. of le Grand Albert work of Albertus Magnus)(my interpretation of peculiar identifications found in 1911 Britannica which seem VERY wrong (speaking of Albert 'the grand' and Albert 'the small' as HRE electors) is confusing people with books (see an accurate footnote in the prologue of Eco's Name of the Rose) Aqua Fortis is *not* identifiable in the Corning Glass ed. of the Mappa Clavicula, earliest known Euro mss. on practical metalwork.                   WinstonSmith  —Preceding unsigned comment added by 74.108.139.186 (talk) 21:40, 21 October 2009 (UTC)

Agenothree
"Nitric acid is also featured on the "Pern" books by Anne McCaffrey, where it is known as "agenothree" because of linguistic drift." Doesn't this sound like AgNO3 - silver nitrate? Nitric acid would be eitchenothree. The part cites the book directly which proves that it can be a mix up. --188.2.116.37 (talk) 10:00, 7 December 2009 (UTC)
 * I don't think it's relevant in any case, so I have removed the comment. -- Ed (Edgar181) 13:19, 7 December 2009 (UTC)
 * It's relevant. First off, having read the books in question, I can tell you that "agenothree" (as it's called) is used as part of the fuel for the Pernese flamethrowers, probably in combination with turpentine or a similar organic compound, as reactions between the two are self-igniting. I doubt silver nitrate would be anywhere near as useful when you need to burn things. Second, as Mister 188.2.116.37 pointed out, linguistic drift - it may well have started as "aitchenothree", but over time it would likely have been the subject of elision and become "agenothree".


 * Just my $0.20 (adjusted for inflation). --Special Operative MACAVITYDebrief me 21:33, 4 January 2010 (UTC)

due to its tendency to adsorb water from the atmosphere.
shouldnt it be 'due to its tendency to adsorb oxygen from the atmosphere.'? —Preceding unsigned comment added by 99.229.206.22 (talk) 10:46, 27 November 2009 (UTC)


 * No. Highly concentrated and/or old nitric acid decomposes slowly, forming water, nitrogen dioxide, and oxygen gas.  The nitrogen dioxide is highly colored, and adds a yellow tint to the acid even in very small concentrations.  Nitrogen dioxide can be removed from nitric acid by addition of a small amount of urea followed by distillation.  At high concentrations, this distillation must be at reduced pressure. Norm Reitzel (talk) 03:30, 16 February 2010 (UTC)

Terrorist Ressam
The sources listed do not support the article; no mention of nitric acid is made. New sources have to be identified to support this assertion, or the Ressam passage will be removed. Bobkeyes (talk) 00:33, 13 April 2010 (UTC)

Spelling of Nitre
I notice an anonymous person has selected the non-UK spellings of both "sulfur" and "niter" - which is fine with me. However, I will point out that when "nitre" was being calcined with clay and green vitreol, it was being done in Europe, so the presumption is that the substance being used was in fact "nitre." Norm Reitzel (talk) 22:34, 28 June 2010 (UTC)

Oxoazinic acid is an irrelevant and non-validated chemical name
A Google search (on 30-11-2010) with Oxoazinic acid only renders 247 results, most from http://www.molport.com or from obscure websites selling chemicals. A common characteristic is that all these sites use the Chemaxon program for automatically generating this name. This name is never used by chemists and very misleading for inexperienced readers. Such a name should be banned from the chembox for avoiding confusing Wikipedia audience and propagating bad nomenclature practices. Thanks, Shinkolobwe (talk) 22:05, 30 November 2010 (UTC)

Proposal to omit the term ‘Oxoazinic acid’ from the chembox of Nitric acid
Main discussion at Wikipedia_talk:WikiProject_Chemicals. I propose to totally omit the term ‘oxoazinic acid’ from the chembox of nitric acid because it seems mostly to be used by spammers or crasy websites supposed to sell chemicals and never by honorable chemical companies such as, e.g., Sigma Aldrich or Merck.

Before adding obscure, or worse, inexact, nomenclature terms to Wikipedia, it is necessary to pay attention to the impact it might have in the real world. Wikipedia is more and more renowned in the field of science and techniques and increasingly used by students or professionals in various fields. Often now, Wikipedia behaves like a resonance box or an amplification system and is also frequently wildly recopied by other websites for unknown purposes. According an inadequate importance to obscure terms such as 'oxoazinic acid' and worse, promoting them as “SystematicName” or “IUPACName” in chemboxes could encourage their use worldwide and in a few years, it could be extremely difficult, if not impossible, to get rid of an erroneous and embarrassing nomenclature. As for a viral infection, a bad habit should be immediately stopped in the egg and no chance left to an ugly contamination to propagate and to develop into a pandemia.

Today, I resumed again my search attempts to collect valuable information about the term 'oxoazinic acid'. Hereafter, the very disappointing results returned by three well established search engines:


 * Google: only 245 results (most of them from http://www.molport.com or from spammers sites trying to sell chemicals !);
 * Google Scholar: only 1 results !
 * ScienceDirect: only 1 results: Article in Press, Corrected Proof, not yet published:

"“A new approach to predict the strength of high energy materials” Original Research Article. Journal of Hazardous Materials, In Press, Corrected Proof, Available online 2 November 2010. Mohammad Hossein Keshavarz, Mohammad Ghorbanifaraz, Hadi Rahimi, Mehdi Rahmani. Department of Chemistry, Malek-ashtar University of Technology, Shahin-shahr, P.O. Box 83145/115, Islamic Republic of Iran."

From the abstract of this paper, it is not possible to verify the claim proposed by the contributor Plasmic Physics because the term 'oxoazinic acid' does not appear in the abstract itself, nor in the title of the paper. The term 'oxoazinic acid' could be attributable to any of the functional groups associated to the compounds cited in the abstract: nitroaromatics, acyclic and cyclic nitramines, nitrate esters and nitroaliphatics.

Ordering the paper costs US $ 41.95 and could causes notable troubles to the person making the order because of the delicate character of the subject treated and the possible negative implications in the daily life. So, in the practice, the information about 'oxoazinic acid' presumably given in the paper cannot be easily verified and such a reference does not fulfill its basic objective, nor confirm anything.

Adding an isolated and obscure reference from a paper even not yet published does not constitute a proof or a valuable argument to demonstrate a doubtful terminology.

This is why, I would suggest to also remove this reference from the main page of nitric acid.

The website of http://www.molport.com also contains unreliable information on strange chemical compounds. One of my most surprising finding was the following one:

Oxoazinic acid plutonium: HNO3Pu

http://www.molport.com/buy-chemicals/moleculelink/about-this-molecule/6107333

Not only, this approximate term does not reflect the very complex chemistry of plutonium, a redox-sensitive radionuclides with multiple valences, but the molport company even proposes to sell it ! As plutonium is a strategic fissile material (and also a highly radiotoxic alpha emitter), its use is severely restricted to avoid the proliferation of nuclear weapons. International treaties and IAEA safeguard standards severely limit plutonium uses and dissemination. It is highly improbable that the molport company should be authorized to sell such a substance. So, I question the content and the value of this website often used by the user Plasmic Physics to support strange nomenclature rules.

All that, simply to say that referring to websites such as http://www.molport.com/ or http://www.chemaxon.com/ for systematic nomenclature purposes can be problematic. Such sites can be useful to draw chemical structures but must always be used with discernment and critical mind. Best regards, Shinkolobwe (talk) 17:58, 4 December 2010 (UTC)

Strong acid?
At the introduction of the article, it is said that "Nitric acid ... is a highly corrosive and toxic strong acid." However, according to the article on Strong acids, it is said that Nitric acid isn't a strong acid, as its pKa is -1.64. According to the data provided on this article, the provided pKa is -1.4. Both are more than the -1.74 threshold.

However, nitric acid is usually referred to as a strong acid. Should the statement be changed into "Nitric acid ... is a highly corrosive and toxic acid and is usually considered to be a strong acid" to be more precise?

Dalcde (talk) 12:03, 3 May 2011 (UTC)

Merger proposal
I propose to merge Aqua fortis into Nitric acid, possibly as a new subsection ("Historical uses"?) of "Uses." Aqua fortis is a small article, and I see no philosophical reason that the two should be separate. (I would suggest keeping the "Alchemical substances" category on the redirect, though.) Roscelese (talk &sdot; contribs) 23:46, 15 January 2011 (UTC)
 * Agree, overdue. I would convert it to a redirect. Aqua fortis has received very few edits/year and it has been around for 5 y. You could change this to a redirect and hardly anyone would notice.--Smokefoot (talk) 04:22, 16 January 2011 (UTC)
 * It's actually kind of funny because when I first joined Wikipedia five years ago, one of my first "creations" was a new redirect of Aquafortis (no space, because the sources I read didn't write it with a space) to this article. It never occurred to me that anyone might have created a separate article until I found aqua fortis.
 * Anyway, I don't anticipate this being at all controversial, but rules say to bring it up in talk. Roscelese (talk &sdot; contribs) 06:11, 16 January 2011 (UTC)


 * In my opion, this proposal is due to a short-sighted view about the nature of an encyclopedia. The principle is that too long articles are split into more convenient ones. If you view the statistics you can see Aqua fortis is viewed about hundred times per day. Few edits may mean it is a good article. Do not change it. --Wickey-nl (talk) 10:56, 16 January 2011 (UTC)


 * Oppose. The person searching for aqua fortis is probably coming from an occurance in literature or alchemy. An archaic description is appropriate. Reaching an article about chemistry is probably not what they expect. There also seem to be edits that remove or relegate archaic names. IIRC, aqua fortis used to be in the chembox, but it was removed. Oil of vitriol is still in the sulphuric chembox, but there's no guarantee it will remain. The logical conclusion of this redirect is to redirect all archaic names: for example, aqua vitae to ethanol. Aqua fortis should remain independent; it has similar rank to aqua regia (which is a mixture and does not have a simple redirect). Glrx (talk) 18:07, 16 January 2011 (UTC)
 * Oppose. Aqua fortis is not relevant to modern chemistry. Unlike the term vitriol, it passed out of modern usage some time ago. Petergans (talk) 21:29, 23 January 2011 (UTC)


 * Close with no consensus to merge. It's been several months, there isn't clear consensus to merge, so I'm removing the merge proposal. Glrx (talk) 01:22, 6 May 2011 (UTC)

Links to use in explosive industry
It is mentioned under fuming nitric acid that "this grade is much used in the explosive industry"

yet there is not even a mention that nitric acid is used in the explosive industry in the uses section. I find this rather bizarre as the use of nitric acid to create explosives arguably revolutionized weapons of the 19th century.

I believe there should be at least a link to the articles on guncotton, nitroglycerine, perhaps cordite as it includes the previous two, perhaps gelignite as it includes nitrocellulose, Ethylene glycol dinitrate, and Trinitrotoluene, as nitric acid is used in the production of all of these either directly or indirectly.24.246.70.135 (talk) 19:01, 2 March 2013 (UTC)

Lewis Structure
The Lewis structure shown here doesn't show the actual hybrid resonance structure. It's lacking the half bond between the 'N' and the two 'O's not bonded to the hydrogen. — Preceding unsigned comment added by 31.59.94.118 (talk) 09:53, 2 May 2013 (UTC)

Reactions with non-metals
The first part of this section needs to be cleaned up, and at least one reference should be added. The description of the nitration mechanism ("The hydroxyl group will typically strip a hydrogen from the organic molecule to form water, and the remaining nitro group takes the hydrogen's place") is completely erroneous. --El Zarco 23:23, 29 December 2013 (UTC) — Preceding unsigned comment added by ElZarco (talk • contribs)

Strength of Nitric acid
As mentioned by another user above, the strength of Nitric acid is controversial. Wikipedia inconsistently describes such an issue since the Strong acid page gives a threshold of "strong acids" at pKa <−1.74, excluding HNO3 with pKa = 1.4, while this page states it's strong.

I'd appreciate any professional explanations so as not to confuse readers and break Wikipedia's reliability.

Thanks! — Preceding unsigned comment added by 58.176.234.103 (talk) 05:35, 13 September 2014 (UTC)

Production remarks
It is stated that before the Ostwald process it was produced by the Birkeland process. This was used for a limited time in one or a few locations (Norway and possibly a few other places). The main product of the Birkeland process was not nitric acid but "Norway saltpeter", i.e. calcium nitrate or calcum ammonium nitrate. The main pre-Ostwald process was a reaction between saltpeter and sulphuric acid KNO3+H2SO4 => HNO3+KHSO4. The reaction 2 KNO3+H2SO4 => 2 HNO3+K2SO4 was avoided as it produced too much nitric oxides.

The absorption of NO2 in water is often witten as 2 NO2+H2O => HNO3+HNO2, is the nitrous acid decomposing fully or are measures to remove it from the acid produced necessary? Some descriptions mentions a bleaching procedure which I assume relates to the treatment of byproducts (probably named for dealing with excess NO2) Is there a problem to produce concentrations higher than 68% directly by absorbing more NO2 (N2O4)? Is this problem to obtain a dry enough stream of NO2? How is the red fuming acid made, by absorbing even more?

Nitric acid is a major commodity and its production deserves comprehensive treatment i Wikipedia. — Preceding unsigned comment added by 150.227.15.253 (talk) 15:49, 23 September 2014 (UTC)

Density
Under "Physical and chemical properties", I've tagged the density as inconsistent since it doesn't match what's in the box to its right.

I'm not a physical chemist so I'm not making any body changes, but I think that that section needs minimal text along the lines of "Nitric acid is supplied in several different forms including azeotropic (concentrated) and anhydrous". After that there should be subsections each with a density, I presume that the current 1.42 is correct for azeotropic/conc at some temperature but it's misleading (and I think I've just seen somebody misled) for it to appear as an overall density.

In all cases the measurement conditions should also be given: are these densities for STP or what? MarkMLl (talk) 09:55, 20 May 2015 (UTC)

Sigma Aldrich cites the density of reagent grade (69-70%) nitric acid at 1.42 KE7KTO (talk) 15:37, 9 June 2016 (UTC)

Toxic?
Nitric acid isn't toxic. It's corrosive for sure but consists of a hydrogen ion and a nitrate ion, neither of which are toxic, at least not "highly" toxic as the article states. — Preceding unsigned comment added by 184.152.61.223 (talk) 20:42, 10 June 2012 (UTC)

Well,I know that HNO3 is toxic because it contains NO2

4 HNO3-->2H2O+O2+4 NO2

But I doubt it because it contains nitrate and Hydrogen ions that are not so toxic. So is it slightly toxic,partly,or extremely poisonous? — Preceding unsigned comment added by 76.124.224.179 (talk) 01:41, 8 July 2012 (UTC)

Nitric acid doesn't contain NO2 unless it's fuming nitric acid. It decomposes into NO2, but on its own doesnt contain any NO2, H+ and NO2-. — Preceding unsigned comment added by 184.152.61.223 (talk) 21:40, 28 August 2012 (UTC)

Nitrates are mildly toxic, but the real hazards come from either the strong acidity, its ability to oxidize substances into more dangerous oxides or explosive substances, or its decomposition or reactions with the release of nitrogen dioxide. Nitrogen dioxide is much more volatile than sulfuric acid, so (unless sulfuric acid is released as an aerosol) it is far more dangerous than sulfuric acid (barring skin contact not recommended for either).Pbrower2a (talk) 03:21, 8 February 2018 (UTC)

Discovery: Jabir, Pseudo-Geber, or ... ?
Synthesis was not recorded circa 800 by Jabir. It is recorded in the "Jabirian corpus" but not until circa 1300 in the Latin De inventione veriatis part of the corpus of Pseudo-Geber. First appearance in print is in 1541. Source Vitriol in the History of Chemistry : by Vladimir Karpenco and John A Norris : from Chem Listy vol 96 2002 pp997-1005. No Jabrian manuscripts survive from 800. Since this is not an alchemical article let us use only verifiable informationJ8079s (talk) 00:34, 11 October 2008 (UTC)
 * However, by not mentioning Jabir at all, the article gives the impression that "Pseudo-Geber" was the discoverer. This source claims that there are in fact earlier versions of the recipe and that Jabir is likely to be the discoverer. --Jorge Stolfi (talk) 01:59, 19 February 2019 (UTC)

Merge back red fuming nitric acid and white fuming nitric acid into this article
I see no good reason to have separate articles for red fuming nitric acid and white fuming nitric acid. They are simply grades of nitric acid. I propose to merge them back into the respective sections of this article. Specific uses call for specific ranges of concentration, but that is true for most compounds. Those two articles have relatively little contents and low quality, especially the white one. Some of that content seems too technical and dated for Wikipedia, and some of it (such as the and  contents) could be factored out to other sections of this article. --Jorge Stolfi (talk) 17:02, 18 February 2019 (UTC)
 * Oppose I wouldn't merge it to nitric acid, but we could use an overall article on nitric acid as a rocket propellant oxidiser, covering nitric acid, WFNA, RFNA, IRFNA and N2O4 all in one place. Andy Dingley (talk) 17:44, 18 February 2019 (UTC)
 * Seems a good idea. Something like Nitric rocket oxidizers? Nitric propellant oxidizers? --Jorge Stolfi (talk) 01:31, 19 February 2019 (UTC)
 * What's a good term for both nitric acid and nitrogen tetroxide?  (I'm no chemist) Andy Dingley (talk) 11:22, 19 February 2019 (UTC)
 * FYI I've let WP:CHEMS know about this discussion. Hopefully some experts will come and help. shoy (reactions) 13:43, 19 February 2019 (UTC)


 * Oppose original proposal but support Andy Dingley's alternative. I don't think there is enough about each of these to stand alone (so the separate grades should be merged...somewhere). But I think nitric acid itself is already long, and the specific application (of the set of related materials) seems like a suitable stand-alone topic to spin out rather than keep in the parent. DMacks (talk) 13:59, 19 February 2019 (UTC)

Wrong interpretation of concentration
The article states: “concentration of 68%w/w (or, 68g of HNO3 dissolved in 100ml of water)“. This is wrong; 68%w/w means that 100g diluted acid contains 68g HNO3. Plausibility check: what should 100% mean? 100g of HNO3 dissolved in 100ml of water? Certainly not. Rigus (talk) 14:42, 6 March 2021 (UTC)

Semi-protected edit request on 26 May 2022
In section 3 Production, the original text is "This is subsequently absorbed in water to form nitric acid and nitric oxide. 3 NO2(g) + H2O(l) → 2 HNO3(aq) + NO(g) (ΔH = −117 kJ/mol)" However, the enthalpy of reaction is wrong. Instead, the correct value is -135.74 kJ/mol.

The enthalpy of formation for NO2(g), H2O(l), HNO3(aq), and NO(g) are 33.10 kJ/mol, -285.83 kJ/mol , -206.28 kJ/mol , 90.29 kJ/mol. And the enthalpy of the reaction can then be calculated follwing the stoichiometry as 2*(-206.28) + 90.29 - (-285.83) - 3*33.10 kJ/mol = -135.74 kJ/mol.

This value is also consistent with. Z zhenyu (talk) 16:57, 26 May 2022 (UTC)
 * ✅ Aaron Liu (talk) 08:35, 4 June 2022 (UTC)

Semi-protected edit request on 15 August 2022
Suggested addition to NOTES:

Writer Anne McCaffrey, in her Nebula-winning novella Dragonrider, makes reference to a caustic liquid called "agenothree" by the fictional sages of that time and place. Anan Isapta (talk) 13:50, 15 August 2022 (UTC)
 * Not done. Nitric acid is so common that adding fictional references to it would be too overwhelming. -- Mvqr (talk) 12:22, 18 August 2022 (UTC)

Semi-protected edit request on 25 October 2021
I recently (7:45 PM, October 24th) got a nitric acid burn and I would like to put the image under the Safety section as I think it would help the readers understand what a nitric acid burn looks like. The image is attached below. It is not very graphic, the skin is only just brown in the burn area. For the caption I will put "A image of a nitric acid burn. The affected skin is brown from the nitric acid reacting with the keratin." Image: https://media.discordapp.net/attachments/891090739688247316/902053196166479923/image4.jpg Thank you. Edward Science Innovators (talk) 04:38, 25 October 2021 (UTC)
 * Red information icon with gradient background.svg Not done: Please make your request for a new image to be uploaded to Files For Upload. Once the file has been properly uploaded, feel free to reactivate this request to have the new image used. &#8209;&#8209; El Hef  ( Meep? ) 13:43, 25 October 2021 (UTC)
 * I think you have to upload it to the Commons. AXO NOV  (talk) ⚑ 11:11, 15 October 2022 (UTC)

An article always cited by a user as Mainstream view.
A user always cite this paper http://www.chemicke-listy.cz/ojs3/index.php/chemicke-listy/article/view/2266 in different articles, calls it mainstream view and straightly reject views of other academicians. There isn't one but numerous other reliable sources that contradict assertions made by the authors of this article of interest. I can list those sources. Also this article doesn't address the primary sources that are cited by other scholars and contradict statements made by author of this article. For example, here, in case of nitric acid, this article hasn't addressed texts like Liber Luminis Luminum Hu741f4 (talk) 16:28, 13 February 2023 (UTC)
 * the mainstream view is that mineral acids were not known to Arabic alchemists:
 * pp. 140-141: The close resemblance between the practise of the Jabirian writers and al-Razi is most marked in their passages on such 'sharp waters'. These waters range from simple mixtures to distillates obtained from complex mixtures. They are not always fluid and some of the processes refer to melting rather than dissolution. But among them we find the rudiments of processes which were finally to lead to the discovery of the mineral acids, sulphuric, hydrochloric and nitric. The mineral acids manifest themselves clearly only about three centuries after al-Razi, in the works of Europeans, some of whom were alchemists, but others of whom were concerned with the production of medical elixirs.
 * : It is generally accepted that mineral acids were quite unknown both to the ancients in the West and to the Arabic alchemists.
 * p. 59: The text is given here in full because of the prevailing notion that Islamic chemists did not produce mineral acids.
 * : between the time when the Summa perfectionis was written and the seventeenth century, the mineral acids–sulfuric, hydrochloric, nitric, and the mixture of the latter two, called aqua regia, had been discovered.
 * By affirming that nitric acid is first attested in a Latin work, Karpenko & Norris 2002 p. 1002 confirm the mainstream view as given by other scholars.
 * Not so with, who self-consciously (see the quote above) contradicts other scholars at every turn, arguing for every individual mineral acid that some or multiple Arabic sources contain recipes for them (he does the same for alcohol and other chemical substances). This is of course interesting, but al-Hassan's views have as of yet not been accepted by other scholars. Reviewers have also noted that al-Hassan's views are often polemical in nature, e.g., Ferrario 2010 p. 132 the tone of an open and fiery polemic against other scholars [...] the tone of the polemics tends to exceed the desirable boundaries of an academic disagreement; Brentjes 2011 The at times rather sharply ideological tone does not improve his arguments.
 * From this it should be clear that al-Hassan's work sits somewhere between minority and wp:fringe, and should therefore be accorded less wp:weight than other scholars. If you think that his views are accepted, it would be nice if you could give a citation of other specialist scholars (i.e. scholars specialized in medieval chemistry) citing al-Hassan with approval. Thanks, ☿ Apaugasma  ( talk  ☉) 17:54, 13 February 2023 (UTC)
 * @Hu741f4: I have reverted this edit of yours due to the reason given in the edit summary. I strongly suggest you discuss here first before adding more sources contradicting the mainstream view. ☿ Apaugasma  ( talk  ☉) 14:05, 14 February 2023 (UTC)
 * Mentioning the view of a notable author which is contradicted by others doesn't mean the entire content should be removed. This isn't being stated in 'general sense'. There is nothing in Wikipedia guideline that states such content should be straightly removed. You can state views of other authors and leave the judgement to readersHu741f4 (talk) 14:16, 14 February 2023 (UTC)
 * There absolutely is a guideline to remove content, in one of our core policies (WP:V) even:
 * You want to include this and similar content, I believe it is not in line with wp:due, and now the onus is on you to get consensus.
 * What that means in the first place is that you should at least consider whether my claim that it is not wp:due may be true. Argue why, according to you, it actually is wp:due, here on the talk. But simply dismissing concerns and edit warring content in is not acceptable. Please do not do that again.
 * Anyways, I will work a bit on a new version of the paragraph and propose it here. ☿ Apaugasma  ( talk  ☉) 14:31, 14 February 2023 (UTC)
 * Anyways, I will work a bit on a new version of the paragraph and propose it here. ☿ Apaugasma  ( talk  ☉) 14:31, 14 February 2023 (UTC)


 * "Consensus may determine that certain information does not improve an article. Such information should be omitted or presented instead in a different article." My edit improves the article in such a way that the readers would know about views of different specialists. The history of nitric acid is unclear. We have several authors who disagree with what you assume as "mainstream view". Their views should be included in this article. A Wikipedia article shouldn't be based solely on views of one group of authors. Hu741f4 (talk) 14:41, 14 February 2023 (UTC)

I don't assume anything, evidence from major historians of chemistry on what the mainstream view is has been presented above. Evidence has also been given that al-Hassan's work is considered polemical and ideological by other scholars, which means that we should use him with care.

WP:DUE/WEIGHT is a core policy, we represent points of view proportionately according to their prominence, not as though they are equivalent and as though we can simply let the reader decide. Relative prominence or weight is crucial, see WP:BALANCE and WP:FALSEBALANCE. Editors can disagree on how the due weight policy applies (i.e., on how prominent a certain view or source is and how it should be presented), but they are not free to simply refuse discussing relative weight.

I propose we first give what all scholars, including al-Hassan himself, admit to be the mainstream view, i.e., that the discovery of mineral acids such as nitric acid is generally believed to go back to 13th-century European alchemy. The minority claims of Holmyard 1931 and al-Hassan 2001 (the former of which is actually outdated and the second self-consciously polemical) should be presented as what they are, i.e., claims contradicting the mainstream view that have not (yet) been generally accepted. Al-Hassan 2001's confused mention of Michael Scot's Liber Luminis luminum should either be relegated to the footnote or left out entirely. 's view should be clearly identified as the one that is in line with the mainstream view. I think calling it "conventional" is a good fit.

My proposal can be read here (the first paragraph of the history section). Let me know what you think. ☿ Apaugasma  ( talk  ☉) 16:34, 14 February 2023 (UTC)


 * There are some minor issues but I have no problem with your proposal as of now Hu741f4 (talk) 17:37, 14 February 2023 (UTC)
 * Okay, I've implemented it for now then. As before, if you want to add another source arguing against the current mainstream view, please discuss on the talk page first.
 * I'm sure that some of al-Hassan's claims will be proven correct by future scholarship (i.e., I strongly suspect that some mineral acids were first described in Arabic 11th-/12th-century sources that have not yet been sufficiently investigated at this time), at which point this article should be updated. ☿ Apaugasma  ( talk  ☉) 18:00, 14 February 2023 (UTC)
 * I have found several scholars who have criticised the works of every scholars that you have mentioned (Malthauf, Needham etc). On the other hand I have also found positive scholarly reviews about Fuat Sezgin, EJ Holmyard and al Hassan. So here no scholar is free from criticism. The conclusion we can make from all this is that "The history of mineral acid is disputed". Also there are many reliable secondary sources supporting the claim of Holmyard, Sezgin and Al-Hassan. Hu741f4 (talk) 20:13, 5 April 2023 (UTC)
 * No, we have to follow WP:DUE. We have to look at what the experts say. I already clarified above what experts say about Al-Hassan's work, i.e. that it is "often polemical in nature, e.g., Ferrario 2010 p. 132 the tone of an open and fiery polemic against other scholars [...] the tone of the polemics tends to exceed the desirable boundaries of an academic disagreement; Brentjes 2011 The at times rather sharply ideological tone does not improve his arguments." Since this is mainly about Al-Hassan (Holmyard is old and obsolete and so not a good source), I am genuinely curious about any positive reviews of Al-Hassan's work that you may cite? In my experience, his work is not well received by other scholars, who like Ferrario 2010 tend to find it interesting and challenging but marred by its unfounded attacks on other scholars and by its high amount of substantial mistakes and general lack of rigor. Despite Al-Hassan's many attacks on William R. Newman's work (e.g., ), Newman hasn't even taken the effort to write a response, which he did do for what are presumable more legitimate criticisms of his work (e.g., ). Among historians of chemistry, Al-Hassan's work is considered WP:FRINGE. Again, if this has recently changed, I would be highly interested in any source which shows the contrary. ☿ Apaugasma  ( talk  ☉) 01:39, 6 April 2023 (UTC)

Semi-protected edit request on 9 June 2023
"The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen."

Inorrect usage of "be (is)" vs "has a". A thing has a particular appearance, it is not the appearance itself.

I suggest a change to "... but samples tend to acquire a yellow cast over time due to ..."

2600:1002:B157:77E4:3C3A:7042:6E4A:CB1E (talk) 10:14, 9 June 2023 (UTC)


 * ✅ ☿ Apaugasma  ( talk  ☉) 15:09, 9 June 2023 (UTC)

Semi-protected edit request on 9 June 2023
"The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen."

Inorrect usage of "be (is)" vs "has a". A thing has a particular appearance, it is not the appearance itself.

I suggest a change to "... but samples tend to acquire a yellow cast over time due to ..."

2600:1002:B157:77E4:3C3A:7042:6E4A:CB1E (talk) 10:14, 9 June 2023 (UTC)


 * ✅ ☿ Apaugasma  ( talk  ☉) 15:09, 9 June 2023 (UTC)

Chronological order
Dear fellow Wikipedians,

I've read the discussion on various claims about the first discovery, and I defer to the opinions of Apaugasma. The only reason I moved Geber up was to make the section a little more chronological. I don't think it is very important now, it gave a good enough overview as it was. But if the earliest history part later expands (cf. Sulfuric acid) chronological order among the attributions (generally accepted or not) might be a bit helpful. The Cosmic Ocean (Please feel free to modify or undo any of my edits as deemed appropriate.) 22:00, 27 August 2023 (UTC)


 * I'm sorry, but your edit gave wp:undue weight to what amounts to either a very small minority or a wp:fringe view (Al-Hassan & Holmyard). It's more important to prominently mention the current mainstream view than to follow chronological order. I have reverted your edit accordingly, though I did add some dates to make the chronology clearer for our readers.
 * The works attributed to Albertus Magnus and Ramon Llull which contain descriptions of nitric acid are almost certainly spurious, having been written by an anonymous 14th-/15th-century pseudo-Albertus and pseudo-Llull. There is a large corpus of alchemical texts falsely attributed to influential 13th-century authors like Albertus Magnus and Ramon Llull, as well as Roger Bacon and Arnald of Villanova, but unfortunately the (extremely outdated: 1830 and 1911) sources we are currently citing do not yet seem to be aware of that.
 * This leaves us with an apparent contradiction between the opening paragraph, where it is (correctly) stated that most scholars believe the first description of nitric acid dates from c. 1300, and the last paragraph where it is mentioned that nitric acid appears in works attributed to 13th-century authors (which is correct, though the attributions are false). Perhaps some readers will infer that these attributions must then be false. But much better would be to find and cite recent high-quality sources, which would explicitly say so and which would allow us to clear this up too. ☿ Apaugasma  ( talk  ☉) 01:49, 28 August 2023 (UTC)
 * I guess I and a lot of other users limit our sources to those that are free, ready at hand, and in English (or pastable in Google translate). Maybe it's time for me to start looking for the best sources rather than the most convenient. The Cosmic Ocean (Please feel free to modify or undo any of my edits as deemed appropriate.)  05:47, 28 August 2023 (UTC)