Talk:Nitric acid

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Lewis Structure[edit]

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 (talk) 09:53, 2 May 2013 (UTC)

Corrosive hazard[edit]

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? 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—the same reaction which causes cut apples to turn brown—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)


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)

NFPA diamond[edit]

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)

Molar mass[edit]

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)

Nitric acid and Egyptians[edit]

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 (talk) 21:40, 21 October 2009 (UTC) 

Nitric acid properties[edit]

The properties of HNO3 are still too vague. Should we add some reactions as illustration for each property?AbelinCAusesobad 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 (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 (talk) 16:21, 16 October 2008 (UTC)


I'm confused with the pKa of nitric.

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 −3! About −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? 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)

Cncentration of Nitric Acid[edit]

Can i concentrate the Nitric acid like H2S04? If not then how can concentrate the Nitric Acid? —The preceding unsigned comment was added by (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)


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

Nitric Acid's Concentration and Oxidation Power[edit]

At what concentration is nitric acid a strong oxidant? At what concentration would it decompose an alcohol, a ketone, carboxylic acid or similar group? This is just rough estimates of course.

Nitric acid's uses[edit]

One of nitric acid's uses is in acid rain?

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 (talk) 06:34, 6 February 2008 (UTC)

what kind of chemical bond is nitric acid[edit]

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! 22:14, 14 May 2007 (UTC)

Making Nitric Acid[edit]

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


You can add information that Polish sciencist invented method to get nitrous from air :) —Preceding unsigned comment added by (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 (talk) 13:15, 7 October 2009 (UTC)

Reaction with Keratin[edit]

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 (talk) 16:35, 25 March 2008 (UTC)

Muslim alchemist[edit]

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 (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)


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)


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)

Industrial Production[edit]

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??[edit]

Wiki fails again. Birkeland-Eyde Process. —Preceding unsigned comment added by (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)


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

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

due to its tendency to adsorb water from the atmosphere.[edit]

shouldnt it be 'due to its tendency to adsorb oxygen from the atmosphere.'? —Preceding unsigned comment added by (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)

Definition of glacial[edit]

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 (talkcontribs) 05:02, 25 August 2009 (UTC)

it means concentrated to the max posible —Preceding unsigned comment added by (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 (talk) 02:25, 9 October 2009 (UTC)


"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. -- (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 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)

Terrorist Ressam[edit]

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[edit]

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[edit]

A Google search (on 30-11-2010) with Oxoazinic acid only renders 247 results, most from 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[edit]

Main discussion at Wikipedia_talk:WikiProject_Chemicals#Controversial_use_of_the_term_.E2.80.98Oxoazinic_acid.E2.80.99_in_the_chembox_of_Nitric_acid.

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 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:[1]

“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 also contains unreliable information on strange chemical compounds. One of my most surprising finding was the following one:

Oxoazinic acid plutonium: HNO3Pu

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 or 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)


  1. ^ Keshavarz, Mohammad Hossein (2010). "A new approach to predict the strength of high energy materials". Journal of Hazardous Materials. In Press, Corrected Proof. ISSN 0304-3894. doi:10.1016/j.jhazmat.2010.10.093. Retrieved 2010-12-04.  Unknown parameter |coauthors= ignored (|author= suggested) (help)

Merger proposal[edit]

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 (talkcontribs) 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 (talkcontribs) 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)


essentially i'm writing a piece of coursework involving the production of potassium nitrate, on the potassium nitrate page it said that it could be produced as "a by-product of the making of nitric acid from potassium nitrate and hydrochloric acid." unfortunately i have been unable to find an equation for this reaction on this page or the potassium chloride page, it seems somewhat frustrating that theres a reference to it and yet no follow up info, I would be grateful if someone were to amend this.

many thanks

Strong acid?[edit]

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)


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 (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 (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 (talk) 21:40, 28 August 2012 (UTC)

Links to use in explosive industry[edit]

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. (talk) 19:01, 2 March 2013 (UTC)

Reactions with non-metals[edit]

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 (talkcontribs)

Strength of Nitric acid[edit]

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 (talk) 05:35, 13 September 2014 (UTC)

Production remarks[edit]

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 (talk) 15:49, 23 September 2014 (UTC)


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[1] KE7KTO (talk) 15:37, 9 June 2016 (UTC)