Talk:Nitrogen dioxide

Deadly Concentration

How much NO2 would you need in the air for it to be an immediate threat?

The article says that nitrogen dioxide is an "insidious deadly poison". Does "insidious" have some kind of meaning in terms of poison/environment control? Or is this merely excessive rhetoric? If rhetoric, then "insidious" should be excised. WpZurp 02:18, 16 Feb 2005 (UTC)

It has a most definite meaning. If you rely on warning signs to let you know you've had too much, it might kill you. It gives no warning. "Very sneaky poison" doesn't sound so scientific. Merck Index Eleventh Edition uses the word "insidious" in its description of nitrogen dioxide. If you type "nitrogen dioxide insidious" into Google, you'll find it and its equilibrium partner nitrogen tetroxide are closely associated with the word "insidious" in the safety literature. Catbar (Brian Rock) 03:24, 16 Feb 2005 (UTC)

Make that third sentence "It gives little or no warning." I've caught a whiff or two of it in the past, and you quickly know you probably don't want to breathe much of the stuff. I think one could choose to ignore it, though, but that's where the "insidious deadly poison" part comes in. Catbar (Brian Rock) 03:29, 16 Feb 2005 (UTC)

Sorry, one more time. Take a look at the phosgene article for another use of "insidious" that defines it in context. Catbar (Brian Rock) 03:40, 16 Feb 2005 (UTC)

The "insidiousness" is due to the fact that symptoms of poisoning (lung edema, that is) appear 12 - hours after one has caught a too large dose. 82.26.171.254 03:09, 21 March 2006 (UTC)

How dangerous was this?

I remember being in a high school chemistry class in about 1997. The teacher left the room and the class clown decided to mix some reagents together in a beaker. I think there was about 30mL of concentrated nitric acid, among other things. Immediately a thick red-brown gas with a pungent ozone-like odour billowed out of the beaker. He watched it for a few seconds then washed the reagents down the sink with water. Of course we were all shouting at him not to be an idiot.

We didn't evacuate and the smell lingered for quite some time. I wonder if anyone can speculate as to how much danger we were in? -- FP ^{<talk><edits>} 05:47, August 6, 2005 (UTC)

• This is not dangerous if done under a fume hood. We did it all the time in my chemistry class. In the open room, you may have been in some considerable danger. {T-Bone 18:52, 19 October 2005 (UTC)}
  • You were not in any serious danger from the nitrogen dioxide, except maybe if it triggered an asthma attack. If that particular experiment produced a lethal dose, there would be a lot fewer chemists around than there are. The conc. nitric acid is what might have caused some real, permanent damage (happily it seems not to have done). Physchim62 01:56, 24 October 2005 (UTC)

• This gas is very dangerous. You have to keep in mind it will create Nitric acid when it reacts with water which there is no lack of inside your lungs. 30mL isn't enough to kill everyone in the room, but if you stuck your nose inside the beaker I can bet there would be some damage done. The effect also are not instant because you mainly die from fluids cloging your lungs. -Loyal

Who ever thought of stucking one's nose inside the beaker? God, people, like you've never heard of the word "dosage". Oxygen is toxic, too. When administered pure, for some time.

Just smelling this gas at low concentrations (like after this experiment in the room) will not kill you nor induce wounds. In concentrations which make people cough, it still isn't so dangerous if you cover your mouth and nose with a piece of cloth. It is a corrosive like chlorine and ozone are. It's not specially toxic like HCN, for example.Endimion17 (talk) 14:42, 25 August 2008 (UTC)

The word "poison" should tell one that it is dangerous. Personally, I have seen brief exposure to a significantly less than 1% by volume concentration cause delayed-onset pumonary edema resulting in loss of consciousness due to hypoxia. The gas was not noticed by smell in that incident. This is not something to fool around with. Some people may be more tollerant of its vasodilation than others, but it CAN kill you at disturbingly low levels. --Rwberndt (talk) 19:42, 21 April 2011 (UTC)

Please verify the data for NO₂ and N₂O₄

The data for NO₂ and N₂O₄ are not very consistent in literature, probably because they always exist together in equilibrium. Verification of the data is recommended before use. R6144 14:45, 26 August 2005 (UTC)

HELP!

Is Nitrogen Dioxide less dense than air?

no, NO2 is more dense by a factor of ca. 46/29.--Smokefoot 00:58, 21 March 2006 (UTC)

The article says density is "3.4 kg/m³, gas at 294.25 K" ... doesn't make sense. Should be approx. 46/29 * 1.2 kg/m3 = 1.9 kg/m3 ... ? —Preceding unsigned comment added by 193.75.93.34 (talk) 08:34, 2 April 2008 (UTC)

Pictur1

why doesnt this molecule have a picture?

SID

SEASONAL RELATIONSHIP OF SUDDEN INFANT DEATH SYNDROME AND ENVIRONMENTAL POLLUTANTS1 TOKE HOPPENBROUWERS2, MARY CALUB, KAZUKO ARAKAWA and JOAN E. HODGMAN American Journal of Epidemiology 1981 Vol. 113, No. 6: 623-635 [1]

Outdoor carbon monoxide, nitrogen dioxide, and sudden infant death syndrome H Klonoff-Cohen1, P K Lam1 and A Lewis Archives of Disease in Childhood 2005;90:750-753 [2]

The San Diego guys where not the first and the link is brooken anyway. Pollution can cause it would be a better clue than NO2 alone.--Stone 06:43, 2 August 2006 (UTC)

created by a plasma?

Does anyone know if NO2 is created when a lit match under a globe is microwaved? This is the subject of an interesting MySpace clip (http://www.youtube.com/watch?v=zM6NLKY2SHk) and I just wondered if the gentleman performing the experiment knew what he was talking about (when he claimed that the process created NO2 ... "So don't breath it!" he said). JimScott 16:31, 8 June 2007 (UTC)

DiNitrogen Tetroxide (Nitrogen Dioxide)

--Jonnerrs 20:24, 30 August 2007 (UTC)In formulating metallic silver(Al)/Gold (Cu/Zn) inks and paints based on cellulose nitrate (NC - Gun Cotton)(disolved in esters), if there is a degree of water present, the cellulose nitrate will be partially reduced to cellulose and NO2=N204. Which becomes apparent as a reddish brown gas, with an astringent smell. I can only cite personal experience here.--Jonnerrs 20:24, 30 August 2007 (UTC)

Bleach

It is grouped as a 'bleach' in the bottom. But nothing is mentioned in the article? —Preceding unsigned comment added by 219.78.11.87 (talk) 09:53, 17 December 2007 (UTC)

Lewis Structures

Are these Lewis structures correct? It doesn't seem possible for NO₂ to have 2 double bonds.

Kundai andrew (talk) 08:39, 3 October 2008 (UTC)

Yeah, they can't be right - 9 electrons round nitrogen.

I think the image below is the closest a Lewis structure can get to representing the bonding in NO₂.

Ben (talk) 11:55, 3 October 2008 (UTC)

The Image isn't showing two double bonds, it's showing a 1.5 bond. Dotted lines mean a "half bond" or a third of a bond, it happens when there are resonance structures. Havabighed (talk) 06:07, 4 July 2012 (UTC)

These comments refer to the article as it was on 3 October 2008, when the image File:NO2-Schema-Lewis.png was included in the chembox. --Ben (talk) 00:11, 6 July 2012 (UTC)

I think it's worth revisiting this issue again. I've made File:NO2-Lewis-resonance.png, but there's also a pair of structures with the unpaired electron on oxygen and no charges. See http://www.madsci.org/posts/archives/2000-02/951452623.Ch.r.html for details. This would be a useful addition to the article if we can explain it well in the text.

--Ben (talk) 18:48, 3 June 2016 (UTC)

NO2 contributes to the formation of fine particle pollution and smog; permissible hourly and annual levels allowed by US EPA

NO2 is formed from vehicle, power plant and other industrial emissions, and contributes to the formation of fine particle pollution and smog.

Short-term exposures to NO2 have been linked to impaired lung function and increased respiratory infections, especially in people with asthma.

The EPA one-hour standard for NO2 is a level of 100 parts per billion (ppb). The annual average standard is 53 ppb.

http://yosemite.epa.gov/opa/admpress.nsf/6424ac1caa800aab85257359003f5337/eb9d73686196b38e852576b60059fbd5!

OpenDocument —Preceding unsigned comment added by Ocdcntx (talk • contribs) 15:49, 26 January 2010 (UTC)

Nitromethane

Is this a compound created by combustion of nitromethane with air (i.e. top fuel drag racing fuel)? I was at a drag race the other day and experienced the exhaust fumes (it's something the fans love to do, apparently). Eyes water, nose stings, throat stings, almost choking, etc.. My educated guess told me it's probably a nitrogen oxide reacting with water in eyes/mucous membranes.. Is NO2 the culprit? --24.21.133.196 (talk) 00:29, 15 July 2010 (UTC)

Wording in the NO2-N2O4 equilibrium section

"The paramagnetic monomer is favored."

Is this some sort of joke? Even after reading the introductions to paramagnetism and monomers, I have no idea which of the two molecules is being talked about. This is supposed to be an encyclopedia, not a chemistry puzzle site. Can somebody please edit it so it's actually helpful to somebody without a PhD in chemistry? — Preceding unsigned comment added by 86.147.85.84 (talk) 19:21, 3 October 2011 (UTC)

No joke. That section is talking about both. The article as a whole talks about the monomer, which predominates at standard conditions. Plasmic Physics (talk) 11:24, 4 October 2011 (UTC)

monomer = NO₂, dimer = N₂O₄ (two molecules of NO₂ bonded together). I agree the wording is probably unnecessary. Why not "NO₂ is favored at higher temperatures, while at lower temperatures, dinitrogen tetroxide (N₂O₄) predominates. Colourless dinitrogen tetroxide (N₂O₄) can be obtained as a solid (melting point −11.2 °C). NO₂ is paramagnetic, while N₂O₄ is diamagnetic." — Preceding unsigned comment added by 98.194.35.233 (talk) 23:48, 13 August 2012 (UTC) Oops, this was me, forgot to log in Vultur (talk) 00:56, 14 August 2012 (UTC)

Yes, I agree this is much clearer as the molecules are identified explicitly before describing them as paramagnetic and diamagnetic. So I have gone ahead and changed the wording, almost as you have suggested. I added that the paramagnetism is due to the unpaired electron. Dirac66 (talk) 00:13, 14 August 2012 (UTC)

Material to be added

Between 2005 and 2011, the concentration of NO₂ across the United States greatly diminished. "The shift is the result of regulations, technology improvements and economic changes, scientists say."<ref>{{cite web|url=http://www.nasa.gov/content/goddard/new-nasa-images-highlight-us-air-quality-improvement/|title=New NASA Images Highlight U.S. Air Quality Improvement|date=26 June 2014|accessdate=15 July 2014|publisher=NASA}}</ref>

Although someone ought to reword the second sentence so as not to plagiarize and expand on some of the technical aspects. - Sweet Nightmares 01:59, 16 July 2014 (UTC)

Interesting tidbit, but Wikipedia is not a vehicle for US-oriented news. --Smokefoot (talk) 02:01, 16 July 2014 (UTC)

You're right, Wikipedia is an encyclopedia where people can learn about things, such as the fact that NO2 pollution in the US has been diminishing. - Sweet Nightmares 16:17, 16 July 2014 (UTC)

Assessment comment

The comment(s) below were originally left at Talk:Nitrogen dioxide/Comments, and are posted here for posterity. Following several discussions in past years, these subpages are now deprecated. The comments may be irrelevant or outdated; if so, please feel free to remove this section.

The article mentioned that Nitrogen and oxygen react at "elevated temperatures" - how high temperatures, precisely?

Last edited at 23:31, 18 June 2008 (UTC). Substituted at 01:19, 30 April 2016 (UTC)

Above 1600 °C (2900 °F), see https://en.wikipedia.org/wiki/NOx#Thermal Simon de Danser (talk) 16:47, 21 November 2020 (UTC)

External links modified

Hello fellow Wikipedians,

I have just modified one external link on Nitrogen dioxide. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

• Added archive https://web.archive.org/web/20050909162153/http://www.euro.who.int/document/E82790.pdf to http://www.euro.who.int/document/E82790.pdf

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 18 January 2022).

• If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
• If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 12:14, 21 December 2017 (UTC)

Greenhouse Gas?

Is Nitrogen Dioxide a Greenhouse Gas? I can't find the answer to this any where on the internet!! - Guest30 — Preceding unsigned comment added by 203.221.110.175 (talk) 06:50, 24 April 2020 (UTC)

Here you go: "Neither nitric oxide nor nitrogen dioxide are greenhouse gases" see http://www.soest.hawaii.edu/mguidry/Unnamed_Site_2/Chapter%202/Chapter2C3.html Wait.... There is more.... "There are also several gases that, although they do not have a commonly agreed upon direct radiative forcing effect, do influence the global radiation budget. These tropospheric gases include carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), and tropospheric (ground level) ozone (O3)." See https://ghginstitute.org/2010/06/15/what-are-greenhouse-gases/ The factors that make up a Greenhouse Gas are it's concentration and it's absorption spectrum.

Simon de Danser (talk) 16:43, 21 November 2020 (UTC)

From the article. "Another study examined the relationship between nitrogen exposure in the home and respiratory symptoms and found a statistically significant odds ratio of 2.23 (95% CI: 1.06, 4.72) among those with a medical diagnosis of asthma and gas stove exposure.[32]"

Should this be 'nitrogen dioxide exposure' rather than 'nitrogen exposure' ? I don't have a copy of the cited reference. Wsmurdoch (talk) 01:03, 5 December 2020 (UTC)wsmurdoch

Human-caused sources and exposure?

The "Human-caused sources and exposure" section of the article refers to indoor exposure from "butane and kerosene heaters and stoves," and gives its source as ref 19, a PDF. I don't see any mention in the PDF of butane or kerosene, though, or even of stoves/ranges - all I see it talking about is "unvented gas heating appliances," which to my mind would be heaters (but not stoves/ranges) using natural gas or propane/LP gas. Butane can be in LP gas, I guess, but kerosene isn't even a gas! Is "heaters" in this PDF elsewhere defined to include stoves/ranges? Why was kerosene mentioned? Am I just being obtuse? :-) Paul314159 (talk) 17:44, 5 December 2020 (UTC)

density at STP

Its stated as 1.880 g/L but if you calculate it with it weight N (14,0067) + 2 * O (15,999) = 46,0047 g/mol. Knowing 1 mol equals 22,4 liter: 46,0047/22,4 = 2,053 g/L. Whicht is right? — Preceding unsigned comment added by 145.8.179.210 (talk) 09:41, 30 March 2022 (UTC)

Only 6 of 40 refs are to chemistry/technology

The article has 40 citations. 34 are to hazards, environment, etc. 6 to technology, chemistry. One appreciates that it takes little expertise to cite hazards, environment, etc, so maybe that is the explanation for this strange emphasis on safety issues, but this ratio is out of proportion, an example of WP:UNDUE. --Smokefoot (talk) 15:17, 5 August 2022 (UTC)

75103 citations in SciFinder

75103 citations in SciFinder to the NO2, of which 48952 have appeared since the year 2002, of which 993 are classified as reviews.--Smokefoot (talk) 15:17, 5 August 2022 (UTC)

Error in NFPA 704 Fire Diamond?

Right now, the reactivity/instability marker is listed as "2," however most sources I've found list it at "0." (See: [3]https://cameochemicals.noaa.gov/chemical/4072). I'm not sure where the rating here was obtained, as I saw no source for that (sorry if I just missed it). I'm going to go ahead and change it to match the versions I've seen elsewhere, but it may be worth someone who's more active in the chemistry areas of Wikipedia to have a look around maybe? 207.191.198.38 (talk) 20:24, 4 March 2023 (UTC)