Talk:Sulfur hexafluoride

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Lewis structure[edit]

lewis structure diagram?


I question the physiological effects of xenon, since it is an inert gas... displacement of oxygen could cause light headed sensation. Source?? Bert 03:48, 13 April 2006 (UTC)

I once read in a medical textbook that xenon can be used as a general anaesthetic, like nitrous oxide, but with fewer side-effects due to its lack of reactivity. It's not simply due to displacement of oxygen by Xe. See for example [1] , [2], [3].

--Ben 10:15, 13 April 2006 (UTC).

Thanks for the references. I've added the info on xenon's anaesthetic properties back into the article. Bert 13:03, 13 April 2006 (UTC)

As you go down the periodic table, the nobel gasses become less inert. Compounds exist. AlbertCahalan 03:31, 15 May 2006 (UTC)

What does Xenon have to do with SF6 (at all)? — Preceding unsigned comment added by (talk) 19:19, 8 September 2015 (UTC)

Is this true?[edit]

Just curious:

"According to my rough estimates the Moon could hold an atmosphere of SF6 (a stable, inert gas) at one bar of pressure for an indefinite period of time. That is if it's protected from solar wind. Light gasses like N2 or O2 would float off even without solar wind. If you wanted to terraform the moon you could put a atmosphere of SF6 to make the pressure and temp comfortable. Then continuously replenish the O2. So mechanism based on genetic engineering of microbes or maybe chemical methods could be used to keep the O2 from flying away. Either way solar wind would still be an issue." (from a board somewhere) Mithridates 02:42, 22 August 2006 (UTC)
So... what purpose would the SF6 serve? Does it act as a greenhouse gas? —Keenan Pepper 05:45, 22 August 2006 (UTC)

I think its main purpose would be to create an atmosphere thick enough that other gases could be added without being knocked out right away, as well as to be thick enough that people would only need oxygen tanks when going outside instead of pressure suits as well. In theory anyway. I don't know anything about this gas. Here's the thread by the way so you can see where the discussion's come from. Mithridates 06:07, 22 August 2006 (UTC)

Only problem would be transporting all that SF6 and O2 to cover the moon. Good luck with that. — Preceding unsigned comment added by (talk) 19:26, 8 September 2015 (UTC)

High Voltage is not 1kV[edit]

High Voltage does not start at 1kV this would be medium voltage. Albeit that warning signs are always going to say HIGH VOLTAGE even if the voltage is 480/277 this is for deterrent purposes. However sometimes in a 480/277 volt three phase distribution system within a building the 480 is referred to as high voltage while the 208/120 voltage is referred to as low voltage, in reality they both fall under low voltage. To further complex things article 490 of the 2005 NEC (for the purpose of the article) calls anything over 600V high voltage. Medium Voltage is typically 5kV-50kv (4160 and 4800 volt systems are typicall classified as 5kV systems)keep in mind there is a difference between "system voltage" and "utilization voltage". Anyway "High Voltage" doesn’t start until approx 50kV; my suggestion is you remove the reference of 1kV and state SF6 is typically used in medium and high voltage electrical applications.

'High Voltage' varies according to jurisdiction. In Australia, the former Electricity commission of NSW called high voltage anything above about 700V. According to the Australian and New Zealand standards (AS/NZS 3000), High Voltage is defined as anything exceeding Low Voltage, being 1000V AC or 1500V DC. Vk2tds (talk) 01:40, 30 July 2009 (UTC)

1KV is high voltage. In any given country's codes and regulations voltages higher than 600 to 750 volts are considered high voltage. 5kV to 50kV or more commonly 69kV are known as distribution voltages, anything higher is known as transmission voltage. —Preceding unsigned comment added by (talk) 00:22, 29 January 2010 (UTC)

Lewis Dot Structure[edit]

How can sulfur accept 6 fluorides? It doesn't have d-orbitals to accept extra electrons, or is there something I'm forgetting?

Indeed, d-orbitals are considered too high in energy to contribute to bonding. In the terminology of Molecular Orbital Theory, bonding is such species are decribed by 3-center, 4-electron bonding, which in effect places substantial electron density on the highly electronegative F atoms. Such molecules are caled hypervalent. PF6- and SiF62- are isoelectronic with SF6. SF4, SO2, SO3, SF2O2, and, indeed, H2SO4 are described with this approach. Ignoring bonding theories, most main group elements heavier than Ne, can bind at least six F atoms around themselves.--Smokefoot 04:13, 25 September 2006 (UTC)
That's not entirely true, as hypervalent molecules such as SF6 and PCl5 can be much better explained by d-orbital bonding, at least outside of MO theory. RedPanda25 20:55, 21 October 2015 (UTC)

Contribution to global warming...[edit]

Is that information regarding SF6's GWP accurate? If SF6's GWP is indeed 22,500 over 100 years, and its mixing ratio is indeed 0.005 ppm, it will have a net effect only 1/3 that of the net effect of carbon dioxide (GWP 1, mixing ratio 365 ppm). Hardly "low".

It's an error. I checked, after getting to the same conclusion as you. According to : Measurements of SF6 show that its global average concentration has increased by about 7% per year during the 1980s and 1990s, from less 1 ppt in 1980 to almost 4 ppt in the late 1990’s (IPCC, 2001). The value 0.005 ppm is off by a factor of 1000 (0.005 ppm would be 5 ppb, which is 5000 ppt). I can edit that later today, if noone objects. Oku 23:23, 11 January 2007 (UTC)

Please do. I came to this talk page with the exact same question in mind 01:59, 12 January 2007 (UTC)
Done Oku 06:02, 12 January 2007 (UTC)
Given that this gas is ~6x HEAVIER than air, I doubt it could go up high enough to reflect the sun's rays to cause a green house effect. It might however be useful for an ACTUAL green house if you trapped it between the layers of double pane glass. TodKarlson (talk) 00:00, 1 December 2012 (UTC)
How much or how little SF6 reflects the sun's rays in irrelevant. A greenhouse gas is a gas which can absorb thermal infrared radiation from the earth. Please leave the commenting to people who have at least a basic understanding of the greenhouse effect. — Preceding unsigned comment added by (talk) 21:19, 10 April 2013 (UTC)
Not irrelevant at all, "any of various gaseous compounds (such as carbon dioxide) that absorb infrared radiation, trap heat in the atmosphere, and contribute to the greenhouse effect." From Merrian Webster and several other references. It absolutely does not mean that it absorbs it from the earth, it could absorb it directly from the Sun. — Preceding unsigned comment added by (talk) 19:34, 8 September 2015 (UTC)

NEMA’s SF6 management guidelines state, “…Over a 50 year service life the emission of SF6 gas due to its use in electrical equipment will not exceed... 5% equipment leakage…” (i.e., 0.1 percent/year). The IEC standard for new equipment leakage is 0.5 percent per year. Actual leak rates are higher in some cases. SChalice 15:27, 23 January 2015 (UTC)

"Not a directory" / Youtube videos[edit]

The complaint that wikipedia is "not a directory" is an awfully weird excuse to remove a link to what I think is a quite informative demonstration video showing the density of SF6. I'm going to list at RfC 'cause I'd really like to keep it. --Deglr6328 09:40, 10 January 2007 (UTC)

WP is not a mere collection of links. There is no reason to just add more and more external links to a page. Youtube is already a site that is under dispute, and though the video shows a nice demonstration, it does not tell more about the compound. --Dirk Beetstra T C 09:55, 10 January 2007 (UTC)
I re-reviewed the video. The only reference directly says 'hexafluorid', which does not say that this is actually sulfur hexafluorid. There is no explanation, there is no extra data. I'm sorry, but this is just another external link, you can also post this on Xenon (where there is sure that hexafluorid is not Xenon, of course). It might make a nice reference on explanation of gases with high molecular weight. --Dirk Beetstra T C 10:01, 10 January 2007 (UTC)
Right, because there's a good chance it could actually be hot uranium hexafluoride. Give me a break. --Deglr6328 01:17, 14 January 2007 (UTC)

I have removed this link:

It is not to a true youtube page, but to a somewhat trashy site. About these links, I don't mind if they appear as references, as plain external links they are not really useful, the wikipedia is not a mere collection of external links, see sites like wp:not, wp:el. If someone would like to write a properly written part in the article, using this as a reference (I'd prefer peer reviewed references as well ..), please go ahead. Thanks. --Dirk Beetstra T C 11:02, 14 January 2007 (UTC)

But what about the original link? 21:38, 20 January 2007 (UTC)
I think that is covered in my previous answer. --Dirk Beetstra T C 01:19, 21 January 2007 (UTC)

Jay Leno also had a thing on this wjs23

I want to have examples in the external links, it just makes sense; this is a source of knowledge, and allot of people only look at the external links. why not show examples of how this stuff works, then they'll remember it.. that's for sure.

and remember... Knowledge is power!

I disagree with Dirk Beetstra, I want the demonstration video in the External Links. This is everyones encyclopedia, I don't think it was right for whoever blacklisted the URL to prevent people from adding it. This links to the video (talk) 17:15, 11 January 2008 (UTC)


I removed the line about SF6 being self-healing. It doesn't seem to make sense when the article continues to discuss the decomposition products.

Self-Healing seems like a strange term for a gas, which would be unfamiliar to many readers. Perhaps if someone made an article self_healing(gas) or something... 03:29, 22 January 2007 (UTC)

The self-healing property refers to that if the SF6 is exposed to an arc, the SF6 disassociates into various sulfur, fluorine, and sulfur-fluorine molecules. When the arc shuts down, the sulfur reacts with the fluorine, producing SF6 again. The main thing is that the fluorine is not free to react with the circuit breaker parts. If you used CCl2F2, you would be left with chlorine and fluorine (amongst other compounds) which would corrode the circuit breaker (or what ever it was insulating) and deplete quantity of gas. The S2F10 while toxic to humans, probably is not too bad for the circuit breaker. Jim1138 (talk) 00:15, 27 October 2008 (UTC)

But, if SF6 breaks down into S and F in an arc, wouldn't the immediate cooling to room temperature solidify the S into a fine powder and the F into a gas? If so, they wouldn't have much kinetics to recombine, would they? So arc byproducts could be corrosive at best, poisonous at worst. Even if the components recombined partially in the heat of the arc/plasma, wouldn't SF4 be more likely than SF6? SF4 is not very healthful. It seems to me that arcs in SF6 dielectric may be more hazardous than is usually stated. David Spector (talk) 18:24, 20 June 2013 (UTC)
The SF
in electrical equipment is contained, except for catastrophic failure, so the products are not released. One would not want to be around venting SF
electrical equipment. Proper maintenance procedures would pump out the SF
so as to not release the products; presumably for both cost and environmental reasons. I am not sure how fast the healing takes place. I would imagine that some corrosion does take place, but then, I would not think that switching / arcing would be a common happening. Proper selection of materials in the electrical equipment would reduce corrosion issues as well. I did restore the mention of "self-healing" in the article and did add a citation. Jim1138 (talk) 21:15, 20 June 2013 (UTC)
Of course the materials are confined in an air-tight space, and this promotes self-healing. That isn't the issue that I raised. I stick with what I wrote since you didn't address the same issues. I know there are references to self-healing, I simply added some personal doubt about safety based on chemical dynamics. The literature on arcs that occur in an SF6 atmosphere doesn't seem to consider the phase difference between sulfur and fluorine at room temperature. Of course, SF6 would also tend to extinguish arcs.(arc extinguishing) Exactly what happens in an arc may depend in part on the strength of the arc and in part on the ambient temperature. It is possible that no chemist has actually conducted experiments and analyzed reaction products. In copper-wire arcs, there is also the question of the generation of copper fluorides, some of which are probably as poisonous as SF4. And the seal on almost anything that is confined eventually breaks--that is why both SF6 and refrigerants are eventually released into the Earth's atmosphere. David Spector (talk) 23:20, 20 June 2013 (UTC)


One paragraph says it's 5 times air's density, another says 6. Which is it? Miken32 06:10, 23 February 2007 (UTC)

However its density (5 times as heavy as air) necessitates proper mixing.

I removed the odd sentence here, as seems unclear in its meaning. If the figure of 6.13 g/cm3 is anything to go by, and the density of air being anywhere between 1.1 and 1.3 g/cm3, I make it 5.11 times denser. That's still pretty dense for a gas, is there any chance that this as the densest (ambient) gas in the world? — Jack · talk · 11:08, Saturday, 31 March 2007

I changed the above density statement and added values for SF6 density for all three phases. While there may be a number of gases that are heavier than SF6. the densest known gas (at STP) is radon (9.73 g/L) - almost 1.6 times the density of SF6 (6.16 g/L). Bert 17:49, 31 March 2007 (UTC)

Sig figs, guys. Sig figs. ~Joules —Preceding unsigned comment added by (talk) 22:23, 26 November 2007 (UTC)

Constant-Pressure Specifc Heat of SF6[edit]

The specific heat of SF6 will change with respect of temperature. I'll appreciate if anyone knows the coefficients that build the 'ideal' gas specific heat (with constan pressure) equation, or any good link on this topic. It goes like Cp0=C0+C1θ+C2θ2+C2θ2

Where the θ=T(Kelvin)/1000 —The preceding unsigned comment was added by Milovac (talkcontribs) 19:22, 5 April 2007 (UTC).

{{nfpa|4|4 ox|4}}

Sulphur Hexafluoride on Google trends[edit]

why is my link being constantly removed even when i have just added it as a reference can support my reference and will not remain same forever hence i posted this comment here

this is an encyclopedia and any news is good news—The preceding unsigned comment was added by (talkcontribs).

Thanks for this discussion. You are adding a link to a blog. As anyone can write a blog, such links are (generally) not allowed as external links, or as source. For the guidelines, see our external link guideline (mentions blogs in the 'links to avoid'), and WP:RS. Using as a reference would probably be a better (that is more reliable than a blog). Hope this helps, thanks again, and have a nice day. --Dirk Beetstra T C 08:12, 28 June 2007 (UTC)

i get your point but you do not seem to get my point imagine how are you going to give that rference which changes every hour

this is the area of my research and finally i have penned a blog on it.

i do research on google keywords appreciation/ reason/ timing/ demography whole day long

wht else do you want and it is not like that the post is giving any wrong information it supports the facts with the screenshot of that. i know bloggers whose citations have been taken without any doubts but even they were ridiculed in their beginning and so am i so, plz allow this citation, you will note i do only 1/2 posts per day and research what causes the rise for eg. come 26 july simpsons the movie keyword would be skyrocketing come the presidential elections hillary clinton and obama will be the most searched people on planet.

i request you you to understand that this is important to me as this shows that my research does have some meaning.

thanking you in advance

Seems to be some contradiction here:

"There is virtually no reaction chemistry for SF6. It does not react with molten sodium."

"reacting with solid lithium as used in the United States Navy's Mark 50 torpedo."

If it reacts with solid Li, then there is no doubt that it will react with Na, especially molten Na.

Also, I'm curious about this: "the result of inhaling SF6 is the opposite of inhaling helium, a reduction in the timbre (not pitch) of the voice." Clearly it changes the fundamental frequency being produced by the larynx, is that not what pitch is?

AWeishaupt 10:29, 6 October 2007 (UTC)

Actually, it doesn't change the pitch, because the larynx still vibrates at the same frequency as when breathing air. As such, it can only affect the timbre. Arts n Sci (talk) 04:22, 25 April 2009 (UTC)

Floating Foil[edit]

There are too many references to being able to float small foil boats on this gas. Just bwecause it's a popular video going around doesn't mean it adds anything to the article. After all, do we add the "notable" quality that you can float small foil objects on it to all the articles on heavy gasses? (talk) 00:00, 1 September 2008 (UTC)

This gas is famous for this, but perhaps all we need is a picture. Graeme Bartlett (talk) 06:34, 9 May 2010 (UTC)
This experiment was done on Mythbusters (2008). TodKarlson (talk) 00:02, 1 December 2012 (UTC)

Other Properties[edit]

I added thermal conductivity and heat capacity from the Air Liquide web site (included the reference). This probably should be placed elsewhere. Where? I noticed with dichlorodifluoromethane this info is in a table in its own section. With Hydrogen, it is in the cheminfo box. I had added an entry to thermal conductivity and referenced the SF6. Jim1138 (talk) 00:34, 27 October 2008 (UTC)

Eight thousand tons[edit]

What kind of ton? Metric, long or short? JIMp talk·cont 23:12, 3 July 2009 (UTC)

Well it can't be metric because that is 'tonne'. (talk) 16:00, 30 January 2012 (UTC)
It's one significant digit. It doesn't matter which ton is being used as long as it's weight and not shipping tons or air conditioning tons or wine tuns. It would be nice to have a citation for this figure and some indication of what era the figure was relevant to. --Wtshymanski (talk) 22:39, 30 January 2012 (UTC)


Isn't it supposed to be sulPHur? (talk) 12:52, 16 July 2010 (UTC)

As described in Sulfur#Spelling_and_etymology, "sulphur" is a UK-style spelling that's been replaced internationally by "sulfur". If this were simply a national difference in spelling we would stick with whatever style that predominates in the article. -- Scray (talk) 15:00, 16 July 2010 (UTC)

Uncited potentially dangerous statements that need citations[edit]

I've moved these uncited, potentially dangerous statements from the main page. Return only after reliable, verifiable citations have been found.

  • It is "nontoxic".
  • Because SF
    is relatively slowly absorbed by the bloodstream
    , it is used to provide a long-term... tamponade or plug of a retinal hole in retinal detachment repair operations.
  • It is a "commonly used" tracer gas in ventilation efficiency measurements.

On a cursory glance, the experiment cited for the statement below was not meant to prove the statements below. Please indicate specific quotes, tables, or figures that support these statements.

In a mixture of 80% sulfur hexafluoride and 20% oxygen. The lungs mix the gases very effectively and rapidly so that the heavy gases are purged along with the oxygen and do not accumulate at the bottom of the lungs.
Yamaguchi, K. (2001). "Inhaling Gas With Different CT Densities Allows Detection of Abnormalities in the Lung Periphery of Patients With Smoking-Induced COPD". Chest Journal. 51 (6): 1907–1916. PMID 11742921. doi:10.1378/chest.120.6.1907.  Unknown parameter |coauthors= ignored (|author= suggested) (help)

Temporal User (Talk) 03:16, 10 November 2011 (UTC)

I marvel at the concern over the increased risk someone has of putting a needle in his eye to blow bubbles in it, because he read about it on Wikipedia. Really, there's no saving people like that. First of several hundred possible citations stuck in. --Wtshymanski (talk) 15:04, 10 November 2011 (UTC)
Have you ever had surgery for a detached retina? It's much like looking through a snow globe for the first couple of weeks; all the crud in your eye obscures the view, and the little SF6 bubble is always there in your field of vision. However, it is immensely comforting to be half way through surgery and to be able to detect motion in the affected eye again. --Wtshymanski (talk) 15:16, 10 November 2011 (UTC)
Thanks for finding the source. Questioning its usage in retina repair wasn't my intent considering I didn't know it involves needles and they weren't mentioned here. I was referring to the statement that it's relatively slowly absorbed (compared to what?). I'm happy you look forward to the time this article will be a featured article with 100's of citations. –Temporal User (Talk) 03:40, 12 November 2011 (UTC)

"Physiological effects and precautions" contains no precautions[edit]

While there are other comments throughout the article on the safety of the gas (see above discussion on toxicity), this section contains no precautions, despite it's heading. This section should either be renamed, or, ideally, modified to include any precautions that should be taken. I suspect that the majority of hits for this page a from folks looking to learn more after seeing a voice-modification video, so having a section with health risks (if any), a reminder to not breath too much lest asphyxiation occur, etc. would be useful. — Preceding unsigned comment added by (talk) 18:59, 6 January 2012 (UTC)

Torpedo fuel?[edit]

If SF6 reacts with lithium to propel torpedoes, why is it that gas-insulated switchgear doesn't burn down every time a breaker opens? This sounds really dubious to me...if SF6 is used as a blanket gas in casting *molten* magnesium, it can't be very reactive. --Wtshymanski (talk) 15:01, 18 December 2012 (UTC)

Well that was educational. The lithium article had a link to an abstract that looks real. --Wtshymanski (talk) 15:27, 18 December 2012 (UTC)

speed of sound in SF6[edit]

Someone check me on this. The speed of sound in SF6 in the main article is claimed to be .44 x speed of sound in air which gives 150 m/s. But using v = sqrt(gamma R T/M) where gamma is the ratio of specific heats (adiabatic constant), R is the ideal gas law, T is temperature, M is molecular mass you get 135m/s at 293 K (20C). This is quite different. The gamma I find is either 1.08 or 1.09 depending on sources (airliquide web site). I don't know if these are reliable figures (and as pointed out elsewhere there is a slight temperature dependence). Looking up specific heats (Perry's Chemical Engineering Handbook) and finding gamma gives 1.7 for gamma and v=163m/s; very different. Wolfram alpha gives 133.9m/s at 20C. Who is right? I would trust the NIST web site if I could get into it but don't have an account. — Preceding unsigned comment added by (talk) 15:25, 1 January 2014 (UTC)

SF6 vs F6S[edit]

In the chembox there is the very non-standard F6S noted as the formula. Interestingly, a Google search seems to draw on the Chembox information and repeat this while everywhere in the article itself, the standard SF6 is used.

By convention a binary formula like this is almost always written with the more electronegative element second. Trying to flip the listing order of sulfur and fluorine in the chembox section 2 doesn't change the displayed formula. Virtually all exceptions to this are where you have a basic compound containing hydrogen like ammonia, NH3. (Jeffj (talk) 13:13, 17 September 2014 (UTC))

I agree that the chembox should display SF6 rather than F6S and have adjusted the box's parameters accordingly. -- Ed (Edgar181) 13:16, 17 September 2014 (UTC)

Melting point vs boiling point[edit]

How come the melting point is shown as higher than the boiling point? Also, these values seem to be shown in the references we cite. Some references however state that the compound sublimes at ambient pressure… –Jérôme (talk) 10:30, 26 November 2016 (UTC)

When the melting point exceeds the boiling point, that means it sublimes. It also means that the boiling point should not be called "boiling" but "sublimation point" instead. In order to melt this, it would have to be under some pressure. Graeme Bartlett (talk) 12:51, 26 November 2016 (UTC)
Cheers ; I understand –Jérôme (talk) 08:33, 27 November 2016 (UTC)

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