Talk:Benzene

NFPA diamond error

Benzene is a Group 1 carcinogen. The white box should therefore feature the phrase "CARC".

I am also surprised by the 2 rating in the health box. Is this from a recent NFPA rating reference? As I believe something that is a group 1 carcinogen tends to be 3 / 4. The health rating of sodium nitrite is 3, and it's used as a preservative in food. — Preceding unsigned comment added by 109.149.157.19 (talk) 22:10, 3 January 2012 (UTC)

The NFPA diamond is actually correct. The NFPA Health number (2) is used to designate its short-term or acute toxicity. Compared to other chemicals you'd have to drink a fair amount of benzene to actually die immediately. There's also a different designation (some places use a star or asterisk) to designate that a chemical has long-term health effects (like cancer). These two designations are different. Armadillo1985 (talk) 17:27, 31 January 2012 (UTC)

Improvements

To get to FA consider: A lead expansion, much more referencing, paragraph expansions and copyediting. --DFS454 (talk) 13:38, 6 April 2009 (UTC)

toxicity of benzene derivatives

Info on derivatives of benzene (i.e. compounds with an aromatic ring) should be elsewhere. The implication of the following paragraph...

"In recent history there have been many examples of the harmful health effects of benzene and its derivatives. Toxic Oil Syndrome caused localised immune-suppression in Madrid in 1981 from people ingesting anilide-contaminated rapeseed oil. Chronic Fatigue Syndrome has also been correlated with people who eat "denatured" food that use solvents to remove fat or contain benzoic acid but causality is unproven."

...is that all compounds that contain aromatic rings are hazardous. Not so! Just as an example, three amino acids (phenylalanine, tyrosine and tryptophan) contain aromatic rings (yet we can't live without them). Topojim (talk) 22:33, 3 August 2009 (UTC)

Benzene>Benzina, Naphtalene>Naphta, Anthracene>ἄνθραξ

I was under the opinion that Benzene came from benzoin indirectly, which gave its name to petrol in some languages (Benzina@italian) which in turn gave its name to benzene as it is found in that fraction while Naphthalene is found in Naphtha, and Anthracene from coal tar in greek (Anthracite gets its root from it too). I find that series quite cool, but I do not remember where I read that benzina is petrol in Italian hence Benzene though. Any ideas? --Squidonius (talk) 09:21, 26 August 2009 (UTC) {{Unanswered}}

Well, the specific etymology is covered in the article, with regards to Benzoin resin and the Asian origins of that word. I did quite a bit of digging around, and there is little to add; the Italian word for petrol certainly is derived from this too, as various dictionaries assert - but that fact is probably not worth adding to this article, and the same is true regarding the origins of the words Naphtalene and Anthracene. The article Naphtha covers the former quite well, but Anthracene does not currently have etymology. Wiktionary defines "ἄνθραξ" as 1. charcoal, 2. a deep red precious stone, a carbuncle, 3. an abscess, a boil, a carbuncle; I would certainly imagine that the origin is related. The article on Anthrax explains that "ἄνθραξ" means coal, and Bacillus anthracis explains that this is due to the dark skin colour that is symptomatic. ; infact, I have just redirected ἄνθραξ to that section.

If you wish to get more information on the subject, I suggest that you ask at the language reference desk. Cheers!  Chzz  ►  02:59, 18 October 2009 (UTC)

Temperature vs vapour concentration under nomal pressure

When a matter changes its phase from solid to liquid and from liquid to gaseous state due to rise of temperature under a constant pressure (i.e., means without change of elevation of location), say normal atmospheric pressure in an enclosed volume, the concentration of the matter in gaseous form in that enclosure will increase from zero to a certain value till it boils(except for matters which sublimate, when there will be a concentration of the matter in gaseous form at all phases). This concentration of gaseous form will vary between matters.

A relation between the temperature and the concentration of gaseous form of the matter

Regards, P K SENGUPTA, CHIEF ENGINEER, HQ CHIEF ENGINEER (AIR FORCE) ALLAHABAD, UTTAR PRADESH, INDIA. pksgkri@gmail.com. Tel +915322580403, +919415315511

I believe you are looking for the vapor pressure curve, LOG10(P) vs 1/T , where P is vapor pressure in mm Hg and T is temperature in degrees K.

LOG10(P) = -1729.434(1/T) + 7.773392

This works between 7.6 and 103.8 degrees Centigrade. To get what you have asked for specifically you use the vapor pressure curve, Raoult's Law, Henry's Law and Dalton's Law. Zambaman (talk) 23:08, 15 January 2010 (UTC)

Is this legible?

Could somebody with a better knowledge of English than mine please take a look at the following sentence in the introductory text of the article: "It is also related to the functional group of aromatic hydrocarbons (arene) which is a generalized structure of benzene". Does this make sence at all? H.tjerns (talk) 08:11, 10 August 2011 (UTC)

Start article on benzene health effects & exposure?

The amount of text and information on the toxicity and carcinogenicity of benzene is very large. Many readers are probably interested in these themes, not a bunch of organic chemistry. And the converse is also probably true. So it may be timely to subdivide this article into one that emphasizes chemistry and mentions its many health effects and a complementary article that emphasizes the health effects and exposure risks but only mentions the chemistry, i.e. that it is important.--Smokefoot (talk) 00:51, 30 April 2012 (UTC)

I am wondering why drugs companies thought of trying to create drugs based on benzene – benzodiazepines
and I seem to remember a school mate who liked sniffing the benzene he found in a school chemistry lab
- and claimed it was intoxicating
Laurel Bush (talk) 10:27, 14 August 2013 (UTC)

The aromatic ring structure is incredibly common in organic chemistry. You can find an aromatic ring structure in pretty much any drug, from amphetamine to Tylenol. An aromatic ring structure by itself is benzene, but other chemicals with aromatic ring structures in them can have vastly different chemical properties.108.131.127.169 (talk) 16:34, 19 October 2015 (UTC)

I'd think it would be more difficult to find drugs without an aromatic ring in them than with. Maybe a pure element like Lithium, but that's about it, because nearly all drugs are organic and organic chemistry is all about aromatic rings. Nearly every chemical in nearly every substance and cell everywhere in your body has an aromatic ring somewhere in its structure. It just so happens to be that the aromatic ring structure by itself in chemistry, is extremely toxic. 2601:140:8900:61D0:A098:6DB2:F89A:6CCF (talk) 22:11, 26 July 2021 (UTC)

Density

2007 edition of CRC Handbook has different value of density at 20 °C on page 15-25.
—DIV (138.194.12.224 (talk) 11:24, 6 September 2012 (UTC))

Kekule's story

The article casts doubt, at some length, on Kekule's account of how he came up with the benzene ring. There are (now) no citations for this. My question: Is there any reason to give equal weight to Kekule's own account and the disbelievers? I don't say we should ignore the doubters, but why do they get prominence? Zaslav (talk) 03:41, 28 January 2013 (UTC)

Solvent use missing

Until the late 1970s, many hardware stores, paint stores, and other retail outlets sold benzene in small cans, such as quart size, for general-purpose use. Many students were exposed to benzene in school and university courses while performing laboratory experiments with little or no ventilation in many cases.

My understanding is that benzene was used by both of these groups as a solvent and the general-purpose use was to remove grease and oil. Can someone who knows for sure add this in?

Also, shouldn't it say in the introductory paragraphs that benzene is an (effective, cheap) organic solvent and that this is the previously common casual use that has been phased out?

Or am I just wrong? The article gives the impression that the only "use" of benzene is as an ingredient to make other things. 89.217.12.82 (talk) 15:44, 28 January 2015 (UTC)

Cyclohexatriene is not benzene

The Information that the systematic Iupac name is Cyclohexa-1,3,5-triene is very misleading. The latter is a hyphothetical resonance structure and does not exists . Contemplating the bond lengths, it is obvious that benzene does not contain double-bonds. Neither in the excellent french version nor in the good german version it is stated that the systematic name is cyclohexatrien. In conclusion, the only correct Iupac name is benzene. Cyclohexatriene is not benzene, but the name of the hyphothetically resonance structure of benzene. Therefore, we should remove this statement. — Preceding unsigned comment added by Nerdinger (talk • contribs) 08:00, 10 December 2015 (UTC)

References

• @Nerdinger: I disagree. Property determined by structure rather than nomenclature. 1,3,5-cyclohexatriene is sure to form a delocalized π bond, consequently, benzene is cyclohexatriene.
  If a compound has a planar molecule, a cyclic conjugated system, and containing (4n+2) π-electrons, follows the Hückel's rule, it has aromaticity. And 1,3,5-cyclohexatriene meet the above conditions, which form a large π bond, so it will inevitably be aromatic. But this doesn't mean the systematic name should be changed. Similar to cyclopentadienyl anion, cyclooctatetraenide anion, cyclooctadecanonaene, these above are all aromatic, why are they not renamed? In addition, 1,3-butadiene also has a delocalized π bond, so it can't be called "1,3-butadiene" and must be renamed? However, This Page also mentioning "cycloalkenes". Benzene/cyclohexatriene is the first aromatic hydrocarbon recognized by humans, predecessors named it "benzene" and found its properties different from common alkenes later, but regularity of aromaticity was not found by humans at that time. Many people don't think that benzene is cyclohexatriene, because when we discussing the delocalization energy of benzene(cyclohexatriene) in lectures, we should compare it with its corresponding imaginary isolated triene structure.
  That is, cyclohexatriene is benzene, and the compound is known as “benzene” as usual. It's just as bicyclo[5.3.0]decapentaene is known as azulene, and nitric acid is usually known as "硝酸" instead of "氮酸" in Chinese. ——339847214sd (talk) 15:38, 30 March 2019 (UTC)

References

No, "benzene is benzene", and one of its resonance contributors looks like it would be called "cyclohexatriene". It's not up to us as editors to say how we think things should follow a pattern of other things, but instead to follow sources and what it actually happening in the real world. I notice the exact page you link never calls this specific chemical by the triene name, but instead only calls it "benzene". As you say, it's imaginary for it to be the triene structure; this article is about the whole compound, not the 1870s-era original idea. That idea is valid to discuss in context, but it's not how we now know the compound to be. Wikipedia is descriptive, not proscriptive. DMacks (talk) 15:04, 6 May 2019 (UTC)

As you said, 1,3-butadiene is also an imaginary structure that can't 1,4-addition.
It isn't the 1870s-era original idea, but while we follow the general systematic nomenclature, it's indeed named so.[3][4] Why don't we think 1,3-butadiene, cyclopentadienyl anion, cycloheptatrienyl anion, cyclooctatetraenide anion and cyclooctadecanonaene are isolated alkenes when we talk about these above, but we have to think cyclohexatriene is an isolated alkene when we talk about it? Why are the others can be named as their Pi electrons isolated, but exclude benzene? What's the product of elimination of 1,3,5-tribromocyclohexane? No one said "alkenes should like common alkenes". Say again, having a delocalized Pi bond doesn't mean the systematic name should be changed. And I have mentioned the Huckel's rule above, cyclohexatriene and cyclopentadienyl anion follow this rule, so they are aromatic, difficult to addition but easy to substitution. 339847214sd (talk) 01:41, 7 May 2019 (UTC)

Here on wikipedia, we follow WP:RS and avoid WP:SYNTH. It's not up to us to decide how it should be based on our use of the rules. The nature of English as it is actually used at this time is that many things are non-patterned exceptions. I've never seen a successful attempt to prescribe usage here. DMacks (talk) 03:58, 7 May 2019 (UTC)

Also, benzene has no double bonds while "1,3,5-cyclohexatriene" would have 3 double bonds. If a compound is discovered that's an isomer to benzene but is found to have 3 double bonds instead of 0, then there should be a page dedicated to it BUT to my knowledge, no such isomer exists 146.90.19.218 (talk) 15:54, 14 February 2021 (UTC)

Unit Help

I am working on posting the magnetic susceptibility organic molecules. I am having a problem every time I enter the units cgs. The wiki program edits my units to cm^3/g and cgs really stand for centimeter * gram * second. Can someone correct the units on this page and leave me a message about avoiding wiki's autocorrect. TerpeneOtto Mon, Dec. 5th 2016. —Preceding undated comment added 18:45, 5 December 2016 (UTC)

TerpeneOtto The parameter to be used is |MagSus= (not Magnetic Susceptibility). And actually, that one was already filled and that is what you saw appearing. (So the {{Chembox}} template did not see or use or alter your input). I have removed your input [5].

For |MagSus=, input=output so if you want to use different units, you can enter |MagSus=-54.84 x 10^6 cgs. (A list of all parameters is here). -DePiep (talk) 20:31, 5 December 2016 (UTC)

Depiep, one more quick question. Has Wikipedia declared a standard for magnetic susceptibility? most tables list magnetic susceptibility in Xm and Xg which is MagSus./ mol and MagSus./ gram. I have a table that lists both for a large number of organic and inorganic compounds from the CRC 64th ed. I'm going to add the Magnetic Susceptibility to the physical properties of all the molecules for identification purposes and I want to get the notation correct with wikis standard. TerpeneOtto Dec 5th, 2016.

I don't know about the standard, maybe MOS:CHEM can clarify this. As for formatting (not units), I'd say we write: 10⁻⁶ (that's code 10<sup>&minus;6</sup>) etc. Also, using SI units is always better, over 'cgs'. -DePiep (talk) 21:15, 5 December 2016 (UTC)

Depiep this was an error on my part, CGS does stand for centimeters*grams*seconds but the table is just providing the form of the SI units and not the actual SI units themselves. I believe wikipedia uses cm^3/g (correct units) like the | MagSus = provides. So I'm going to publish my data in cm^3/g. Thanks for your help. The Magnetic Susceptibility data will be a tremendous addition to Wikipedia! TerpeneOtto ca. 22:45, 5 December 2016 (UTC)

First, please always sign a post with four tildes: ~~~~. That will save your name with any post.

cm^3/g is ok then, but please do code cm<sup>3</sup>/g, → cm³/g. See?-DePiep (talk) 22:45, 5 December 2016 (UTC)

TerpeneOtto (talk) 06:16, 6 December 2016 (UTC) So I was talking to someone today and we decided to publish the data in terms of cm³/mol. The data in our table has more sig figs in cm³/mol and when the data is published in with the mole ratio it really highlights the differences between molecules and that helps someone distinguish molecules that are similar. I really believe either choice is fine as long as we post the relation between grams and mols on the magnetic susceptibility page. Dec. 5th, 2016.

Image - Gas pump

I am against the gas pump image idea. Benzene is not a major component of gasoline (less then 1%). The majority of gasoline is t-butyl methyl ether. Benzene is closely related to things like paint thinners, NOT gasoline. Can someone remove the request for the gas pump image or provide information that relates benzene to gasoline? TerpeneOtto Dec. 5th, 2016. — Preceding unsigned comment added by TerpeneOtto (talk • contribs) 21:16, 5 December 2016 (UTC)

Joke names

I have removed from the infobox archaic and confusing name "phene", and joke name "phenyl hydride".

If we want to have Joke section, I'd add also [1]helicene, monocene, hexadehydrocyclohexane, hexadehydronorcycloheptane, hexadehydrohomocyclopentane, cyclohexakissexi(methane-1-yl-1-ylidene), (1,2,3,4,5,6-deloc)-1,3,5-cyclohexatriene, benzenaphane, ... —Mykhal (talk) 22:53, 11 May 2017 (UTC)

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Revise first paragraph? Is benzene really an important component of petrol (gasoline)?

The first paragraph of the article may need revision. My memory of the smell of benzene (from when I was a chemist years ago) is that it has a characteristic smell, but is not what I would call "sweet". I doubt that it accounts for the smell of petrol (gasoline). Much later the article states (accurately) that benzene accounts for only 1% of gasoline, even less in the U.S.; so is it really an "important component" of gasoline? I pose these question esp. for those editors who have actual sensual contact with benzene, or who may know more than I do about gasoline chemistry, which is not a lot.Ajrocke (talk) 20:57, 7 February 2018 (UTC)

Most people always thought that C
₆H
₆ is perfectly insoluble in H
₂O (including me).

However, the "solubility" lists some nonzero values. Alfa-ketosav (talk) 18:17, 3 July 2018 (UTC)

It all depends on the definition of insoluble. If you are looking for perfectly insoluble (0 mol/L) then it isn't insoluble. Sometimes anything below 0.1 mol/L is considered insoluble. In that case benzene is insoluble as it is about 0.02 mol/L. ~ GB fan 19:12, 3 July 2018 (UTC)

There are heavy benzenes.

So, titabenzene, zirconabenzene, cerabenzene, hafnabenzene and even plumbabenzene, thoriabenzene and the hypothetical rutherfordabenzene and flerovabenzene are (possibly) aromatic. Alfa-ketosav (talk) 18:17, 3 July 2018 (UTC)

Whether such species are notable and whether they are aromatic are debatable. Such species seem (to me at least) to be of interest to a fairly small handful of academics. We have a short article on Metallabenzene.--Smokefoot (talk) 18:50, 3 July 2018 (UTC)

But we substitute only 1 CH with 1 MH, without additional ligands. Alfa-ketosav (talk) 19:04, 7 July 2018 (UTC)

Such things are pretty esoteric, existing only in the imagination of computational chemists. The problem one runs into is described by the double bond rule. And the use of MH (vs M-R) really limits scope. --Smokefoot (talk) 19:29, 7 July 2018 (UTC)

There's been a computational chemistry study of titanabenzene at least. But it seems that it's not aromatic. Double sharp (talk) 22:22, 14 November 2022 (UTC)

nazi references

The articles says nazis administered benzene injections. Not only is it using the slang "nazi" but also uses sources that come from a museum and a tourist website. Are these valid references of information for wikipedia? In my opinion it should not be and it must find valid sources and be rewritten or moved to a nazi article or be deleted all together. — Preceding unsigned comment added by 2A02:A44D:793F:1:F4D1:451:DE36:9FBB (talk) 15:03, 16 October 2021 (UTC)

While better sources would certainly be appreciated, I think that the Auschwitz-Birkenau State Museum is reliable enough a source to keep this in. ☿ Apaugasma (talk ☉) 15:12, 16 October 2021 (UTC)

I suspect it is a mistranslation. Eduard Krebsbach used gasoline as an injection chemical, and gasoline translates to "benzin" in German. Benzene is less common and more expensive compared to gasoline, which would make it hard to access. --spiritprince☎ 19:17, 10 July 2022 (UTC)

even ignoring the possible mistranslation raised by spiritprince, having "Genocide" under "Routes to Exposure" makes it sound like you need to avoid genocide to prevent contact with Benzene. Its not a bad message, I fucking hate the stuff, but it sounds quite silly and I laughed when I saw it. I'd bet that the vast majority of people will already try to avoid being genocided, regardless if Benzene is involved. 2604:3D09:1284:6B00:FD50:B271:F487:DEE6 (talk) 02:03, 7 August 2022 (UTC)