Talk:Acetylene

Untitled

Bryan, I note the very close similarity between this acetylene article and the one I put under "Links." This is almost too close for comfort...actually it is too close for comfort.

Perhaps, if the article were developed further, it wouldn't look so much like copyright infringement. --LMS

Not sure what to do with it other than simply rearranging the sentances more and perhaps substituting synonyms; this is pretty close to a simple list of facts, and facts are uncopyrightable. I'll give it a shot, though. -BD

Which article?

What's that stuff?

What is the black substance that comes off from the flame and floats away into the air when starting up an oxy-acetelyne torch?

Lampblack. Of course, it wouldn't be surprising to find it contains buckyballs as well.

Atlant 22:02, 30 March 2006 (UTC)

wha?

Please correct the following: a liquid does not sublime, by definition. A material can not sublime at its boiling point, again by definition (although there may be exceptions...) The boiling point can not be BELOW the melting point (under the same pressure and temperature).

I changed the melting point to the latest (1931) value reported in the webbook 171.65 K (link: http://webbook.nist.gov/cgi/cbook.cgi?ID=C74862&Units=SI&Mask=4#Thermo-Phase). Marenero (talk) 20:49, 16 July 2012 (UTC)

I believe this change is based on an error. Rather than add a long explanation in the middle of this old discussion, I have added a new section below. See Talk:Acetylene#Melting point, boiling point, triple point, sublimation Dirac66 (talk) 01:42, 17 July 2012 (UTC)

The completely trivial (sorry, guys) list of side combustion products is unenlightening and certainly incomplete (eg how about NOx compounds and COR or COOR where R is multitude). The opinion that the sweet smell of pure C2H2 is pleasant is not in accord with my experience. The last paragraph is in dire need of rewriting. Its only partially intelligible and has garbled syntax and grammar. One of your links states that polymerization can occur at 15 psig. So which is it? The 1st paragraph has a run on sentence that is one for the books. Is it transported in acetone? If so then why not mention it. Whats the pressure in a tank or a tanker? No mention of toxicity. 400 C is NOT a low temperature for a hydrocarbon (with multiple bonds).

Acetylene can be easily stored in pressurized gas cylinders. What do you think how people weld? They have to tanks oxygen and acetylene. The acetylene is definetely not dissolved in acetone. It is correct that acetylene may explade at 100 kPa pressure (which is 1 atmosphere) but only in the presence of oxygen. It won't do anything on its own. Also the acetylene oxygene flame is one of the hottest burning flame of any hydrocarbon we know

From my distant memory Acetylene will decompose at around 15psi spontaneously, releasing lots of energy (in an explosion). It is stored in Acetone in welding cylinders to prevent this (as it dissolves readily and thus has a lower partial pressure). There are hotter flames using different oxidisers or reducers, but acetylene + oxygen is the hottest hydrocarbon - oxygen flame AFAIK. --njh 11:41, 25 May 2006 (UTC)

Acetylene or ethyne

Why does the article claim that the chemical name of the compound is acetylene when it should be ethyne? In alkyne it states that the acetylene is officially known as ethyne which I assume is refering to IUPAC nomenclature.

• I think that we should use IUPAC names everywhere and then have redirects from common names, rather than the alternative. But it'll never happen.Jaredjeya (talk) 20:56, 7 November 2014 (UTC)

I think we should follow the usage of most recent textbooks and scientific articles. IUPAC is not the only authority. Dirac66 (talk) 14:13, 9 November 2014 (UTC)

if you told me acetylene, i never would have thought it would be ethyne! stick to iupac! RaftaReads (talk) 17:07, 23 September 2020 (UTC)

Why "acetylene"?

Why is the compound even called acetylene at all? I see no similarities to the acetyl radical. No methyls, no carbonyls (not even an oxygen atom), nothing.

The OED gives the etymology as [f. ACETYL + Gr. -ηνη female descendant, weaker derivative: see -ENE.

The Oxford Dictionary of English gives the origin as: mid 19th cen.: from acetic acid + -yl + -ene.

See also EtymOnline, Wiktionary:Acetylene, reactions of alkynes.

Acetylene can be hydrated to acetaldehyde, which contains the acetyl group and may account for the name. Acetyl compounds could, in principle at least, be dehydrated (often a facile reaction, no change in oxidation state) to C₂H₄ - an unsaturated hydrocarbon (hence -ene) from an acetyl group, hence acetylene.

Ben (talk) 19:04, 2 February 2009 (UTC)

But the hydrated form is not the educt, which is called acetylene. (??!!) alternatively: acidify ethylene glycol, acetethylene(glycol)--> acet(h)ylene (ethylene glycol --> -H2O --> ethylene oxide/epoxide--> -H2O --> acetylene; epoxide may polymerize, but sulfuric acid can dehydrate the epoxide, I guess)--Smiles :( :\ :o :() (talk) 02:56, 11 April 2015 (UTC)

Why?

History and tradition, most likely some misconception by the person(s) who first discovered or synthesized it.

Look up how hydrocarbon came about from early experimenters calling them 'watered carbons' due to all the hydrogen in them which had to be an indicator of water involved in the processes that create them. Of course the assumptions were wrong but hydrocarbon stuck as the name of that class of compounds.

You might be thinking of carbohydrates? --njh 11:43, 25 May 2006 (UTC)

Generation and storage

Here's a free e-book that contains plenty of information on the gas.

http://www.gutenberg.org/etext/7969

I've no idea how old it is, but the text has a "feel" to it that appears to date it to the early 20th century. There's no metric units mentioned and the terms 'Sulphuretted Hydrogen' instead of hydrogen sulphide and 'Phosphoretted Hydrogen' instead of phosphine are definately old terminology. Unfortunatly it's just the text, none of the illustrations are included.

Ethyne is far more appropriate

I think we all agree that acetylene is a silly old confusing name- please change it to ethyne

Wow. Now you only need to convince hundreds of thousands of welders, etc.

Google test:

• Acetylene: 3,550,000 hits
• Ethyne: 94,100 hits
• Ethine: 12,900 hits

Atlant 17:26, 13 June 2006 (UTC)

Ethine is most DEFINITLY wrong!

Now in the past women wore corsets and were not allowed to vote! Thankfully we don't all live in the past!! :D

Times are a changing!

Acetylene does not make sense from a chemists Perspective wheras ethyne DOES

Whats the alcohol used to make vodka more than just potatoe water: is it "grain alchohol" or is it ethanol!

Give it a few years mate and you'll let women vote too!

Blonde2max 18:55, 17 June 2006 (UTC)

Ethyne may be the correct name to chemists, but everyone else calls it acetylene. There are already redirects in place for "ethine" and "ethyne". Just add a sentence in the article that explains the confusion between acetylene and ethyne and be done with it.

Bizzako 2:28, 02 August 2006 (MDT)

Don't change it to ethyne. I'm a chemist and I call it acetylene. Most simple, common chemical compounds are primarily known by their trivial (non-systematic) names. Check out this page - it is an online version of IUPAC's Blue Book (organic nomenclature bible). It categorically states that the name acetylene is retained. That's straight from the horse's mouth.

What WP editors seem to be confused about is the difference between rigidly systematic nomenclature and IUPAC recommendations. Although in schools, we are generally taught to always use the systematic name, this is in fact for the purposes of education and to not overload students by making them learn loads of trivial names off by heart. In scientific practice and in general commercial and industrial settings, calling acetylene by the name ethyne would usually be considered to be excessively pedantic and would most likely cause confusion.

In response to Blonde2max's comments, yes ethanol is generally called ethanol by chemists, but acetaldehyde is generally not called ethanal, nor is formaldehyde ever called methanal. Toluene is always used in preference to methylbenzene, as are many, many other compounds. Acetone, not propanone. Acetic acid, not ethanoic acid. The list goes on. Keep this page called acetylene.

Ben 21:05, 2 August 2006 (UTC)

I would disagree that formaldehyde is never called methanal, as well as other examples you give. It really depends on the generation of the person involved, especially when the IUPAC name is less cumbersome than the trivial one eg ethanal v acetaldehyde. In addition of course the IUPAC names reveal the relationships between different chemicals and avoid the silly situation of talking about say methanol being metabolised into formaldehyde when methanol to methanal would be much simpler. Booshank (talk) 14:39, 2 February 2009 (UTC)

IUPAC nomenclature rule A-3.2 notes that "The name "acetylene" for HC≡CH is retained." --Spoon! 08:53, 23 December 2006 (UTC)

I'm absolutely confident that calling ethyne ethyne will not create confusion, or if only perhaps amongst people who just use it for some technical purposes and don't really care about what it actually is. And mind you, ethanoic acid, ethanal, methanal and propanone are the more commonly used forms of names in MODERN chemical literature. Trivial names are more often still used for complex yet common substances, such as toluene, glucose, etc. 129.67.54.6 (talk) 18:46, 20 January 2009 (UTC)

The modern chemical literature almost always calls HC≡CH acetylene, and the same goes for H₃C-CO₂H (always acetic acid), H₃C-CHO always acetaldehyde), (H₃C)₂C=O (always acetone) and so on. I just checked SciFinder and Web of Science for HC≡CH in papers published since 2000. 8227 papers contain "acetylene", while only 439 refer to "ethyne" (ratio of 19:1). I checked a few of the papers that do contain the word "ethyne", and all of them had it as part of a longer name, such as phenyltrimethylsilylethyne in Chem. Eur. J. 2008, 14, 11557–11564.

Ben (talk) 16:29, 2 February 2009 (UTC)

I wouldn't argue that ethanal is more common than acetaldehyde, but to say it is always acetaldehyde is plainly incorrect. See for example just three I found from a simple search:-

Abatement of volatile organic compounds: oxidation of ethanal over niobium oxide-supported palladium-based catalysts http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFG-47CH5X3-G&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=fa4c0401af4c301a6b5c654e0f7f2275

Numerical Studies of a Thermokinetic Model for Oscillatory Cool Flame and Complex Ignition Phenomena in Ethanal Oxidation Under Well-Stirred Flowin Conditions http://journals.royalsociety.org/content/603389500572155m/fulltext.pdf

An ab initio study of muons in ethanal: http://www.iop.org/EJ/abstract/0953-8984/9/15/015

Ethanal etc are plainly perfectly acceptable, if not the most common forms. Booshank (talk) 19:29, 2 February 2009 (UTC)

There are a few chemistry papers that use "ethanal" (although one of those papers was a physics one), but acetaldehyde is far more common (ethanal 77, acetaldehyde 4983, ratio 65:1, WoS, 2000-2009). Similarly, ethanoic acid 114 papers, acetic acid 22809, ratio 200:1 and methanal 69, formaldehyde 12381, ratio 179:1.

I think you see the point. You're right that there's nothing incorrect about ethyne etc, but the article name should clearly remain acetylene.

Ben (talk) 19:46, 2 February 2009 (UTC)

I am not arguing for the page to be renamed Ethyne as it is obviously not the most commonly used term, which is the Wikipedia criteria. I prefer ethyne as it is more logical and more concise in my opinion, but that is beside the point. What I am arguing for is against an unnecessary snootiness in regards to the systematic names and that the name ethyne should be prominent in the article as a) it is considered acceptable by IUPAC and is to be found in scientific literature and b) it is the name most encounter when learning chemistry. Acetylene is not a substance in everyday use by most people and therefore ethyne will be the only name encountered by many. Booshank (talk) 22:50, 2 February 2009 (UTC)

Be bold and make the changes you think appropriate. Then we can discuss them here. Make sure it's clear that acetylene outnumbers ethyne in the literature by around 20:1.

You say that most people don't encounter acetylene (depends how you mean encounter!) but I've known there is a substance called acetylene since I was about six years old (probably because of oxy-acetylene lamps), yet I only came across the term ethyne when I was 14 and studying GCSE science. I don't think alkynes were actually on the syllabus so I might not have seen the word ethyne until I did A-level chemistry, aged 17. Considering that most people do not take chemistry beyond GCSE (and probably a similar situation worldwide), I imagine the majority of the public have heard the term acetylene and not ethyne.

Ben (talk) 08:09, 9 March 2009 (UTC)

bad wording? Acetylene is not so hot.

"Oxyacetylene is the hottest burning of all fuel gases." What counts as a fuel gas? There are hotter stuffs: [1]. A whole bunch of poluynes go noncharted in thèrmokemistry. -lysdexia 20:40, 30 September 2006 (UTC)

Flawed Nanotechnology Concept?

In the "Uses" section:

"Acetylene has been proposed as a carbon feedstock for molecular manufacturing using nanotechnology. Since it does not occur naturally, using acetylene could limit out-of-control self-replication."

In the "Natural occurrence" section:

"Acetylene is a moderately common chemical in the universe... Natural acetylene..."

How could the two quotes square with each other? Given the second one, the first is conceptually flawed. Shawn D. 16:37, 25 July 2007 (UTC)

Underwater?

We've been studying reactions in chemistry lately, and yesterday we demonstrated the synthesis and combustion of acetylene. Did I hear my teacher wrong when he said that some acetylene torches can burn underwater? —Preceding unsigned comment added by 71.190.143.208 (talk) 19:32, 25 October 2007 (UTC)

Acetylene torches have their own oxygen tank. Maybe that's enough to make them burn underwater? --Itub 14:53, 26 October 2007 (UTC)

The combination of the bottled acetylene combined with the bottled oxygen could theoretically allow it. However, on the torch tips I know of, the acetylene and oxygen streams combine externally after exiting individual holes -- the water could entrain the gases and prevent them from mixing and igniting or maintaining ignition. Shawn D. 15:46, 29 October 2007 (UTC)

I just looked at the article on oxy-fuel welding and cutting. From what it says, it seems to me that oxy-acetylene torches could work underwater, but only at very low pressures, so hydrogen is used instead. --Itub 08:50, 30 October 2007 (UTC)

Dallas acetylene fire

There was a major fire in Dallas, Texas a few years ago involving an welding company's headquarters. Hundred of tanks blew up, many hit the nearby freeway, nearly hitting cars (one direction of which was closed, the other wasn't). Is there an article for this? If there is, I can't find it. One of the amazing things is no one was killed. --98.232.182.66 (talk) 04:09, 21 September 2008 (UTC)

I found three articles quite easily on Google:

Fox News: Acetylene, Propane Gas Canister Explosions Rock Dallas

The Dallas Morning News: Dallas explosion injures 3, snarls traffic

There's also a New York Times comparison of this incident with a similar one in Houston.

Ben (talk) 11:50, 21 September 2008 (UTC)

Decomposition

The Compression section says "acetylene gas is fundamentally unstable, and will decompose in an exothermic reaction if compressed to any great extent." I can't find anywhere in the article, though, what it becomes when it decomposes. What are the decomposition products? Ian01 (talk) 04:14, 7 October 2008 (UTC)

Not sure, but I suspect carbon and hydrogen. I think what's meant by "fundamentally unstable" is that acetylene has a positive heat of formation; that is, the reaction H2 + 2C -> C2H2 is endothermic. --Itub (talk) 07:01, 7 October 2008 (UTC)

Is it true that acetylene tanks have to be stored and transported standing up and not lay on their sides?

I heard a rumor that you have to store and transport acetylene tanks standing up and that if you lay them on their sides they will explode?

I don't use acetylene, but I do use a GTAW welding rig with pressurized argon. My argon tank lays on its side in a cradle under my welding bench.

I think it's safer to have gas tanks lay on their sides and not standing up as they could not tip over if they are already laying on their sides.

I don't want to change the article because I only heard this as a rumor. Is there any cited source that talks about en explosion that is caused by someone laying an acetylene tank on it's side? Allyn (talk) 13:44, 25 July 2009 (UTC)

It is true that it is recommended to transport and store acetylene tanks in an upright position but not because they will explode it is because of the acetone in them. If acetone gets up to the valve and it can easily when the container is lying down you will have difficulties lighting up the torch. — Preceding unsigned comment added by 212.91.126.148 (talk) 05:59, 20 September 2011 (UTC)

I grew up with a story, from my father in some sort of chemistry, that the cylinders were acetylene in acetone in bentonite, and that laying down the cylinder would release the acetone from the bentonite and cause uncomfortable amounts of acetylene to come out of solution. I was a kid at the time, so if I've mangled the details, I won't be surprised. ArthurDent006.5 (talk) 07:03, 10 August 2014 (UTC)

This website United States Department of Labor: Special Hazards of Acetylene includes the words ACETYLENE CYLINDERS SHOULD BE STORED AND USED IN THE UPRIGHT POSITION AND FIRMLY SECURED TO PREVENT FALLING OR BEING KNOCKED OVER. (their capitals) Dirac66 (talk) 12:28, 10 August 2014 (UTC)

The tanks can be transported on their sides, but that is not recommended procedure. No harm will come to the tank, or acetylene. If they are laid horizontal, they have to be placed upright and left to stand for a period of time ( recommended several hour minimum ) until the acetone is given time to settle. If this does not happen, then the liquid acetone can get into the regulator and hoses, and cause sputtering of the flame, and potentially damage or failure of the equipment, notable the seals. Since acetylene is extremely flammable, a leaking cylinder in an enclosed space can create a violent explosion, frequently with no resulting after fire, as it can tend to blow itself out. — Preceding unsigned comment added by 70.121.157.34 (talk) 04:38, 20 March 2016 (UTC)

I have now added a link to the above noted US Dept of Labor (Mine Safety and Health Administration) site, which explicitly specifies the upright position. Dirac66 (talk) 16:02, 20 March 2016 (UTC)

Natural occurrence

Here's a link to an article that would seem to contradict the information in the Natural occurrence section.

http://www.newscientist.com/article/dn19005-hints-of-life-found-on-saturn-moon.html —Preceding unsigned comment added by SargeWallace (talk • contribs) 13:36, 6 June 2010 (UTC)

Move?

The following discussion is an archived discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the move request was: Speedy close (no move). No clear rationale provided for move and is contrary to WP:COMMONNAME so speedy close per WP:SNOW. Feel free to propose anew with a potentially persuasive rationale. Born2cycle (talk) 01:03, 15 January 2011 (UTC)

---

Acetylene → Ethyne —

• WP:ALUM 75.15.161.185 (talk) 21:23, 14 January 2011 (UTC)
  • WP:ALUM says nothing that would impact the naming of this article. -- Ed (Edgar181) 21:41, 14 January 2011 (UTC)
• Most people call it acetylene. Anthony Appleyard (talk) 21:32, 14 January 2011 (UTC)
• Oppose: Wikipedia:Naming_conventions_(chemistry)#General_rule is the guideline to follow. "Acetylene" is by far the most common name in commercial, industrial, and academic settings. -- Ed (Edgar181) 21:40, 14 January 2011 (UTC)

The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Melting point, boiling point, triple point, sublimation

From section wha? above:

1. Beginning of old comment (added 2005 Oct.1 by numbered editor) Please correct the following: a liquid does not sublime, by definition. A material can not sublime at its boiling point, again by definition (although there may be exceptions...) The boiling point can not be BELOW the melting point (under the same pressure and temperature). Etc.

2. Added today by Marenero:

I changed the melting point to the latest (1931) value reported in the webbook 171.65 K (link: http://webbook.nist.gov/cgi/cbook.cgi?ID=C74862&Units=SI&Mask=4#Thermo-Phase). Marenero (talk) 20:49, 16 July 2012 (UTC)

3. My comment: First, the phase behavior of acetylene is now explained in the article section Physical properties: changes of state. The triple point is at pressure higher than 1 atm, so the liquid can not exist at 1 atm (as for the better known case of CO₂). The value given for the melting point is actually the triple point, and the value given for the boiling point is actually the sublimation point at 1 atm, and yes, this is lower than the triple point (again as for CO₂).

Since melting point here actually means triple point, the latest value reported in the webbook is actually the 1950 value reported as a triple point, which is 192.4 K. This is close to the webbook values from before 1931, suggesting that the 1931 value is an error. The value in the article before today was actually this 1950 value fron the webbook.

Other more recent sources agree. The Handbook of Chemistry and Physics (60th edn 1979-80, page C-302) lists the melting point of ethyne as -80.8 oC, which is 192.35 K. And the Merck Index (13th edn 2001, p.17) says -81 oC with subl in parentheses. Therefore I suggest we return to the 1950 value. The infobox does note that it is the triple point at 1.27 atm, with more detailed explanation in the Physical properties section. Dirac66 (talk) 01:38, 17 July 2012 (UTC)

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Identifying Acetylene

I'm currently doing an apprenticeship for fabrication and in another fabrication book it notes that Acetylene has a strong garlic smell. would this be the "marked" odour that's mentioned at the beginning of this article? Wiki states that it is odourless in its pure form but has a marked odour commercially due to impurities. — Preceding unsigned comment added by 82.39.201.117 (talk) 08:49, 9 February 2021 (UTC)

Density

Hello, may you have different references or parameters, but your density is wrong. In the English version it is written 1,097 kg/m^3 (without information about the other parameters) but in the German one (with reference) with 1,1772 kg/m^3 (at standard conditions). Please correct or specify it. [Added 29 April 2021 by editor 2003:f9:872d:f806:a5dd:6a6c:2915:874]

The Infobox of this English article has a link at the bottom saying Infobox references, but it does not seem to lead to any useful statement of where the value 1,097 kg/m^3 comes from. In effect it is unsourced. On the other hand the value in the German article does have an intelligible source (even with my very limited German!), so I am tempted to just insert the value from the German article here, with the German reference. Does anyone have a better idea? Dirac66 (talk) 00:21, 19 May 2021 (UTC)

Done. I have now added the value and source from the German article. Dirac66 (talk) 18:11, 16 June 2021 (UTC)

Copyright problem removed

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Discovery: carbide reacts to form carbide??

The Discovery section now says: "By heating potassium carbide with carbon ... [Davy] produced a residue of what is now known as potassium carbide." How can potassium carbide react to form potassium carbide??

This was changed on 2022 January 2 from "By heating potassium carbonate with carbon ..." which at least had a reactant different from the product. However the reaction with carbonate was not very clear either - what happens to the oxygens?? And I cannot make much sense of the references given. Can someone make sense of this reaction and then correct the sentence? Dirac66 (talk) 03:32, 22 January 2022 (UTC)

Confusing sentence

From the "Discovery" section: "By heating potassium carbide with carbon at very high temperatures, he produced a residue of what is now known as potassium carbide, (K2C2), which reacted with water to release the new gas."

So he heated potassium carbide and got potassium carbide out of it? What is this sentence supposed to mean?

2A02:8108:96C0:6D08:1816:CC57:5704:15FB (talk) 17:52, 7 February 2022 (UTC)

It actually says "By heating potassium carbonate with carbon at very high temperatures, he produced a residue of what is now known as potassium carbide, ... Dirac66 (talk) 01:12, 12 May 2023 (UTC)

What is reduced carbon?

Perhaps I'm being dull but I'm not sure what "reduced carbon" is. The article says "oil supplanted coal as the chief source of reduced carbon".

Does it simply mean pure carbon (graphite), or does it mean carbon with a formal charge/oxidation state less than it normally is? In typical molecules such as hydrocarbons, carbon's formal charge tends to be 0. And it doesn't tend to be reduced further in reactions.

I feel that it's possible the editor related isolating pure carbon to isolating pure metals, which do tend to have a reduced oxidation state after the purifying process. But this would be an incorrect analogy.

But I may be missing something here and I haven't found out how to read or translate the cited source, so any insight's appreciated. 35drake (talk) 13:55, 1 February 2023 (UTC)

It means carbon with a lower oxidation state than the maximum of +4 in CO₂. Dirac66 (talk) 01:07, 12 May 2023 (UTC)