Liquid Gas - Oxymoron?
Mardon
Fukushima nuclear plant. In that article there is a sentence that begins:
"A blast of liquid gas stemmed a leak this week..."
I know a gas can become a liquid under certain conditions of temperature
and pressure. That said, I don't think it would ever be correct to use
"liquid" as an adjective to describe a gas. What I think is acceptable are
terms like "liquid nitrogen" or "liquid hydrogen". I suspect the Fukushima
workers used a product like this and that the Globe & Mail author
substituted the generic term "gas" for the actual name of the element that
was used. Is it proper usage to do so? I would think not, since that
seems to lead to an oxymoron.
Harrison Hill
Surely it is a typo for "liguid glass".
annily
> The Globe and Mail's iPhone App contains an article this morning about the
> Fukushima nuclear plant. In that article there is a sentence that begins:
>
> "A blast of liquid gas stemmed a leak this week..."
>
> I know a gas can become a liquid under certain conditions of temperature
> and pressure. That said, I don't think it would ever be correct to use
> "liquid" as an adjective to describe a gas. What I think is acceptable are
> terms like "liquid nitrogen" or "liquid hydrogen". I suspect the Fukushima
> substituted the generic term "gas" for the actual name of the element that
> was used. Is it proper usage to do so? I would think not, since that
> seems to lead to an oxymoron.
I suppose what they mean is a liquid that turned to gas when the
pressure was reduced (i.e. it was gas previously liquefied by the
application of pressure, like LPG), but I agree, "liquid gas" is an
oxymoron.
--
Long-time resident of Adelaide, South Australia,
which probably influences my opinions.
Bertel Lund Hansen
> The Globe and Mail's iPhone App contains an article this morning about the
> Fukushima nuclear plant. In that article there is a sentence that begins:
> "A blast of liquid gas stemmed a leak this week..."
> I know a gas can become a liquid under certain conditions of temperature
> and pressure. That said, I don't think it would ever be correct to use
> "liquid" as an adjective to describe a gas.
There is no other way if one wants to keep the term general and
at the same time describe the condition. In Danish the
corresponding term is quite common. And "liquid fluid" is
certainly not better.
"Liquid gas" gets 827'000 hits on Google.
> Is it proper usage to do so? I would think not, since that
> seems to lead to an oxymoron.
I think "gas" has two relevant meanings: a condition and a
designation for a substance that is a gas at normal temperatures.
"Noble gasses" would be an error if it were not so. They do not
cease to be noble when converted to liquid form.
Would you say that CO2 is a gas? Or do you each time specify the
temperature interval where this is true?
--
Bertel, Denmark
Harrison Hill
It would be difficult to plug a gap with that sort of a stopper. More
likely perhaps that they meant this:
Peter Duncanson (BrE)
The headline contains the phrase "
--
Peter Duncanson, UK
(in alt.usage.english)
Peter Duncanson (BrE)
Message continues:
... leak plugged with radioactive glass"
Well, the glass might become radioactive over time.
The leak was actually plugged as described in this news report quoting
the power plant operators:
Liquid glass successfully plugs radioactive leak at crippled
Fukushima nuclear plant
....
A Tepco spokesman said: 'The leaks were slowed yesterday after we
injected a mixture of liquid glass and a hardening agent and it has
now stopped.'
"Liquid Glass" is the common name of a solution of Sodium Silicate. It
is not the same as molten glass.
http://www.ehow.co.uk/how_6550183_make-sodium-silicate-solution.html
Sodium silicate, also known as "liquid glass," as a versatile and
widely used solution. Sodium silicate is known as liquid glass for
good reason: When the water it is dissolved in evaporates away, the
sodium silicate bonds into a solid sheet of glass[1]. Heat tempering
makes the silicate patch harder, but the solution can still be used
for fireproofing wood and stain-proofing concrete if applied and
allowed to dry at room temperature.
[1] That might be better stated as "a solid glassy sheet". It is not the
same, as far as I know, as glass obtained by vitrification.
Mike Barnes
>The Globe and Mail's iPhone App contains an article this morning about the
>Fukushima nuclear plant. In that article there is a sentence that begins:
>
>"A blast of liquid gas stemmed a leak this week..."
Did they mean "liquefied gas"?
--
Mike Barnes
Cheshire, England
Peter Moylan
> Mardon <mgb7...@hotmail.com>:
>> The Globe and Mail's iPhone App contains an article this morning about the
>> Fukushima nuclear plant. In that article there is a sentence that begins:
>>
>> "A blast of liquid gas stemmed a leak this week..."
>
> Did they mean "liquefied gas"?
>
--
Peter Moylan, Newcastle, NSW, Australia. http://www.pmoylan.org
For an e-mail address, see my web page.
Skitt
> Mardon wrote:
>> The Globe and Mail's iPhone App contains an article this morning about the
>> Fukushima nuclear plant. In that article there is a sentence that begins:
>>
>> "A blast of liquid gas stemmed a leak this week..."
>>
>> I know a gas can become a liquid under certain conditions of temperature
>> and pressure. That said, I don't think it would ever be correct to use
>> "liquid" as an adjective to describe a gas. What I think is acceptable are
>> terms like "liquid nitrogen" or "liquid hydrogen". I suspect the Fukushima
>> workers used a product like this and that the Globe& Mail author
>> substituted the generic term "gas" for the actual name of the element that
>> was used. Is it proper usage to do so? I would think not, since that
>> seems to lead to an oxymoron.
>
> Surely it is a typo for "liguid glass".
... which, in turn, is a typo for "liquid glass".
--
Skitt (SF Bay Area)
http://come.to/skitt
Prai Jei
No probs here. We make the distinction the other way - a substance that is
in the gaseous state but is normally liquid (or solid) at room temperatore,
is more correctly described as a *vapour* rather than a gas. Obviously,
what is meant by "liquid gas" is a substance that is normally a gas at room
temperature, but has been liquefied by pressure alone without having to be
kept cold. We really need a separate word to describe this state, but there
is none that I can think of.
Butane is the most common example of a gas that can be liquefied in this
way. Acetylene will also liquefy under pressure, but the liquid is
extremely dangerous, susceptible to explosive decomposition. (Commercial
acetylene cylinders store the gas a different way.) Nitrogen, hydrogen and
oxygen require cold temperatures as well, since the "critical temperature"
(the maximum temperature at which a liquid can be obtained) for these gases
is well below room temperature in each case.
--
ξ:) Proud to be curly
Interchange the alphabetic letter groups to reply
Mark Brader
>> The Globe and Mail's iPhone App contains an article this morning about the
>> Fukushima nuclear plant. In that article there is a sentence that begins:
>
>> "A blast of liquid gas stemmed a leak this week..."
Still uncorrected at:
http://www.theglobeandmail.com/news/any/article1975874/
>> I know a gas can become a liquid under certain conditions of temperature
>> and pressure. That said, I don't think it would ever be correct to use
>> "liquid" as an adjective to describe a gas.
Bertel Hansen:
> There is no other way if one wants to keep the term general and
> at the same time describe the condition...
There is, actually: "liquified gas" (or "liquefied", if you prefer), as
mentioned by someone else in the thread.
However, in this case, as mentioned in still other responses in the thread,
the mention of "gas" was simply an error.
--
Mark Brader | "This man must be very ignorant, for he answers
Toronto | every question he is asked." -- Voltaire
m...@vex.net | "'I resemble that remark!'" -- Steve Summit
Bertel Lund Hansen
> However, in this case, as mentioned in still other responses in the thread,
> the mention of "gas" was simply an error.
What a shame. I was just warming up.
--
Bertel, Denmark
Bertel Lund Hansen
> Butane is the most common example of a gas that can be liquefied in this
> way. Acetylene will also liquefy under pressure, but the liquid is
> extremely dangerous, susceptible to explosive decomposition.
So is the gas. It's actually much worse than hydrogen which is
quite explosive.
--
Bertel, Denmark
Mike Lyle
Can one still buy carbide pellets for acetylene lamps? For
unscrupulous fishing, you apparently put one in a small tin can,
punched a hole in the lid, and sank it in the stream. I assume the
rapid evolution of gas led to shock wave as the tin burst, and you
scooped the finny denizens in as they rose belly-up to the surface, as
my father said one used to in Australia after firing a rifle into a
pool.
--
Mike.
Stephen
> The Globe and Mail's iPhone App contains an article this morning about the
> Fukushima nuclear plant. In that article there is a sentence that begins:
>
> "A blast of liquid gas stemmed a leak this week..."
>
> I know a gas can become a liquid under certain conditions of temperature
> and pressure. That said, I don't think it would ever be correct to use
> "liquid" as an adjective to describe a gas. What I think is acceptable are
> terms like "liquid nitrogen" or "liquid hydrogen". I suspect the Fukushima
> substituted the generic term "gas" for the actual name of the element that
> was used. Is it proper usage to do so? I would think not, since that
> seems to lead to an oxymoron.
It's acceptable in situations where a substance that is normally a gas
at room temperature -- such as butane -- is compressed until it changes
into its liquid state -- like the liquid you see splashing around in a
cigarette lighter when you hold it up to the light, or hear sloshing
around inside the gas tank of your barbecue. What is clearly known as a
gas has been converted to liquid form, and it's quite okay with me to
call it liquid gas. LPG stands for liquefied petroleum gas, so there's
an alternative for those who insist on absolute accuracy.
--
Stephen
Ballina, NSW
Skitt
> Bertel Lund Hansen wrote:
>> Prai Jei skrev:
>>> Butane is the most common example of a gas that can be liquefied in this
>>> way. Acetylene will also liquefy under pressure, but the liquid is
>>> extremely dangerous, susceptible to explosive decomposition.
>>
>> So is the gas. It's actually much worse than hydrogen which is
>> quite explosive.
>
> Can one still buy carbide pellets for acetylene lamps? For
> unscrupulous fishing, you apparently put one in a small tin can,
> punched a hole in the lid, and sank it in the stream. I assume the
> rapid evolution of gas led to shock wave as the tin burst, and you
> scooped the finny denizens in as they rose belly-up to the surface, as
> my father said one used to in Australia after firing a rifle into a
> pool.
Ah, memories of the underwater demolition exercises next to the
re-gunning pier at Hunters Point Shipyard. Fish-fry for lunch!
Yes, I spent some working days at Lockheed's HPS facility, right next to
the huge bridge crane.
http://www.sfexaminer.com/files/tmp/pollution1.jpg
Peter Moylan
> No probs here. We make the distinction the other way - a substance that is
> in the gaseous state but is normally liquid (or solid) at room temperatore,
> is more correctly described as a *vapour* rather than a gas.
As I understand it a vapour is not a gas, but a collection of liquid
droplets. The "steam" you see coming out of a kettle is not steam at
all, but water vapour. (There's also gaseous steam present, but it's
invisible.) Ditto for clouds.
annily
Oh, I completely forgot to read the rest of the sentence properly. I
though it said the liquid gas was what was leaking, not what stemmed the
leak.
Eric Walker
[...]
> I know a gas can become a liquid under certain conditions of temperature
> and pressure. That said, I don't think it would ever be correct to use
> "liquid" as an adjective to describe a gas. What I think is acceptable
> are terms like "liquid nitrogen" or "liquid hydrogen". . . .
I reckon the difficulty arises from common use of the word 'gas" to
signify not only the physical state of matter, but also a particular
substance, which may or may not be in gaseous form (in the U.S., one
fuels automobiles with "gas", which is short for gasoline).
--
Cordially,
Eric Walker
Mike Barnes
>The Globe and Mail's iPhone App contains an article this morning about the
>Fukushima nuclear plant. In that article there is a sentence that begins:
>
>"A blast of liquid gas stemmed a leak this week..."
Now that I realise they meant "glass", the sentence seems even wronger.
A "blast" is inherently in motion, and the glass had stemmed the leak
only when it had stopped.
Apteryx
Are they confusing dam and blast?
Apteryx
Donna Richoux
I think you're demanding too much from cause and effect. The Liquid
Glass is applied by spraying. That's the blast. After it's on, it is
supposed to stop the leak. *
Can't you say "An injection of vaccine prevents the disease" even though
it's not the actual injection that does the prevention, but whatever
microbial action that follows?
* The plant administration says the Liqiud Glass worked, but others
aren't so sure. Article:
http://www.digitaljournal.com/article/305415#ixzz1J1v9YSS5
--
Best - Donna Richoux
Peter Duncanson (BrE)
wrote:
There may be other leaks.
Media reports seem to be brief and conflated forms of what the company
TEPCO actually reported.
From a TEPCO press release (in slightly dodgy English):
http://www.tepco.co.jp/en/press/corp-com/release/11040904-e.html
<quote>
....
*Unit 5 and 6
....
*At approximately 9:30 am, April 2nd, we found that there was water in
the shaft for storing power cable (concrete product) near the intake of
water for Unit 2, the radioactive air dose was over 1,000mSv/h and the
water spilled into the sea from the crack (approximately 20 cm) on the
side of the shaft. We injected fresh concrete to the shaft twice,
however, we could not observe a change in the amount of water flowing
into the sea. Therefore, we considered that a new method of stopping the
water and determined to use the polymer. Necessary equipment and experts
of water shutoff will be dispatched to the site and after checking the
condition, we began to stop water shutoff and were injecting polymer on
April 3rd. On April 4th, we injected the tracer from the vertical shaft
of the trench to start to examine the water current. We did not observe
reduction of flow or change of color or water leaking. We checked the
diagram and confirmed the route. At the same time, we checked the
situation of the pit in detail and considered the possibility that the
water was not from the pit, rather, from the joint between the piping
upstream of the pit and the duct, then the water seeped through a layer
of gravel below the piping. In order to stop that seepage from the layer
of gravel, we decided to conduct the water sealing to the bedrock around
the piping. We arranged for the specialist and gathered equipments. On
April 5th, liquid glass was injected to the bedrock. Tracer was put
through the two new holes drilled near the pit to investigate the water
flow. At 2:15 pm, April 5th, it was observed the water with tracer came
out from the crack on the concrete wall of the pit. At 3:7 pm, April
5th, injection of coagulant from the holes was initiated and we have
confirmed
the outflow from the crack on the concrete wall of the pit has stopped
at 5:38 am, April 6th. We confirmed water level has not been rising in
the turbine building of unit 2. On April 6th, a countermeasure by using
rubber plate and fixer was implemented to prevent discharge of
radioactive materials, and we are continuously monitoring for any
existence of leakage.
<endquote>
John O'Flaherty
<ma...@peterduncanson.net> wrote:
That solution is also called "water glass", which can be confusing.
When you pick up a transparent container of it, it's surprising
because it's 2.4 times as dense as water.
--
John
Prai Jei
space-time continuum:
> Prai Jei skrev:
Hydrogen will not explode unless there's another substance present that it
can combine with e.g. oxygen. Liquefied acetylene is perfectly capable of
exploding on its own. Notice that I described it as decomposition not
combustion.
Prai Jei
continuum:
> Prai Jei wrote:
>
>> No probs here. We make the distinction the other way - a substance that
>> is in the gaseous state but is normally liquid (or solid) at room
>> temperatore, is more correctly described as a *vapour* rather than a gas.
>
> As I understand it a vapour is not a gas, but a collection of liquid
> droplets. The "steam" you see coming out of a kettle is not steam at
> all, but water vapour. (There's also gaseous steam present, but it's
> invisible.) Ditto for clouds.
I think you'll find that your definition of vapour is wrong. The "gaseous
steam" *is* water vapour, and it is invisible. The cloud of water droplets,
which is visible, is not water vapour, but simply that - a cloud.
Garrett Wollman
Prai Jei <pvstownse...@ntlworld.com> wrote:
>I think you'll find that your definition of vapour is wrong. The "gaseous
>steam" *is* water vapour, and it is invisible. The cloud of water droplets,
>which is visible, is not water vapour, but simply that - a cloud.
And for our next lesson, we will demonstrate that air and water are
not colorless after all, but in fact blue. When that's over with, we
can move on to deconstructing that nonsense they taught you in primary
school about how planes fly.
-GAWollman
--
Garrett A. Wollman | What intellectual phenomenon can be older, or more oft
wol...@bimajority.org| repeated, than the story of a large research program
Opinions not shared by| that impaled itself upon a false central assumption
my employers. | accepted by all practitioners? - S.J. Gould, 1993
David Hatunen
> Mardon <mgb7...@hotmail.com>:
>>The Globe and Mail's iPhone App contains an article this morning about
>>the Fukushima nuclear plant. In that article there is a sentence that
>>begins:
>>
>>"A blast of liquid gas stemmed a leak this week..."
>
> Did they mean "liquefied gas"?
Does it say what the gas was?
Is the substance applied to the leak in a liquid or gaseous state?
I do point out that if a gas is liquified it is no longer a gas.
--
Dave Hatunen, Tucson, Arizona, out where the cacti grow
David Hatunen
> Mardon set the following eddies spiralling through the space-time
> continuum:
>
>> The Globe and Mail's iPhone App contains an article this morning about
>> the Fukushima nuclear plant. In that article there is a sentence that
>> begins:
>>
>> "A blast of liquid gas stemmed a leak this week..."
>>
>> I know a gas can become a liquid under certain conditions of
>> temperature and pressure. That said, I don't think it would ever be
>> correct to use "liquid" as an adjective to describe a gas. What I
>> think is acceptable are
>> terms like "liquid nitrogen" or "liquid hydrogen". I suspect the
>> Fukushima workers used a product like this and that the Globe & Mail
>> author substituted the generic term "gas" for the actual name of the
>> element that
>> was used. Is it proper usage to do so? I would think not, since that
>> seems to lead to an oxymoron.
>
> No probs here. We make the distinction the other way - a substance that
> is in the gaseous state but is normally liquid (or solid) at room
> temperatore, is more correctly described as a *vapour* rather than a
> gas. Obviously, what is meant by "liquid gas" is a substance that is
> normally a gas at room temperature, but has been liquefied by pressure
> alone without having to be kept cold. We really need a separate word to
> describe this state, but there is none that I can think of.
The word you're looking for is "liquid", for that is what it is. The fact
that it's under pressure doesn't change that fact. Water is liquified
steam (or vapor, if you like) kept under pressure but that pressure is
normal atmospheric pressure so we don't notice. But just put some water
in a vacuum and see how long the liquid lasts.
David Hatunen
> Prai Jei wrote:
>
>> No probs here. We make the distinction the other way - a substance that
>> is in the gaseous state but is normally liquid (or solid) at room
>> temperatore, is more correctly described as a *vapour* rather than a
>> gas.
>
> As I understand it a vapour is not a gas, but a collection of liquid
> droplets.
No. Vapour is just a gas, but it's usually mixed into the atmosphere when
it's called a "vapor". Water vapor in the air is humidity. If the air
temperature falls below the dew point the vapor condenses into tiny drops
and become fog if it's on the ground and a cloud if it's above your head.
The cloud you see is condensate.
But I've given up trying to maintain this distinction in public.
> The "steam" you see coming out of a kettle is not steam at
> all, but water vapour.
No.
(There's also gaseous steam present, but it's
> invisible.)
Yes.
> Ditto for clouds.
The clouds are invisible?
David Hatunen
> It's acceptable in situations where a substance that is normally a gas
> at room temperature -- such as butane -- is compressed until it changes
> into its liquid state -- like the liquid you see splashing around in a
> cigarette lighter when you hold it up to the light, or hear sloshing
> around inside the gas tank of your barbecue. What is clearly known as a
> gas has been converted to liquid form, and it's quite okay with me to
> call it liquid gas. LPG stands for liquefied petroleum gas, so there's
> an alternative for those who insist on absolute accuracy.
As for accuracy, I don't care if it's petroleum gas or not, if it's
liquified it's not a gas.
Garrett Wollman
David Hatunen <dhat...@cox.net> wrote:
>As for accuracy, I don't care if it's petroleum gas or not, if it's
>liquified it's not a gas.
Passive voice. It was a gas once, but now it *has been* liquefied.
(And in the future it will be a gas again, as you can't burn the
liquid.[1])
-GAWollman
[1] Ignoring exotic oxidizers like O2F2 and ClF3.
Peter Duncanson (BrE)
<dhat...@cox.net> wrote:
>On Fri, 08 Apr 2011 14:59:57 +0100, Mike Barnes wrote:
>
>> Mardon <mgb7...@hotmail.com>:
>>>The Globe and Mail's iPhone App contains an article this morning about
>>>the Fukushima nuclear plant. In that article there is a sentence that
>>>begins:
>>>
>>>"A blast of liquid gas stemmed a leak this week..."
>>
>> Did they mean "liquefied gas"?
>
>Does it say what the gas was?
>
>Is the substance applied to the leak in a liquid or gaseous state?
>
>I do point out that if a gas is liquified it is no longer a gas.
The gas was the variety of glass known as "a typo".
R H Draney
>
>On Fri, 08 Apr 2011 14:59:57 +0100, Mike Barnes wrote:
>
>> Mardon <mgb7...@hotmail.com>:
>>>The Globe and Mail's iPhone App contains an article this morning about
>>>the Fukushima nuclear plant. In that article there is a sentence that
>>>begins:
>>>
>>>"A blast of liquid gas stemmed a leak this week..."
>>
>> Did they mean "liquefied gas"?
>
>Does it say what the gas was?
>
>Is the substance applied to the leak in a liquid or gaseous state?
>
>I do point out that if a gas is liquified it is no longer a gas.
A chair is still a chair
Even though there's no one sitting there
But a chair is not a house
And a house is not a home
When there's no one there to hold you tight
And no one there you can kiss goodnight.
-- Hal David
....r
--
Me? Sarcastic?
Yeah, right.
David Hatunen
> Bertel Lund Hansen set the following eddies spiralling through the
> space-time continuum:
>
>> Prai Jei skrev:
>>
>>> Butane is the most common example of a gas that can be liquefied in
>>> this way. Acetylene will also liquefy under pressure, but the liquid
>>> is extremely dangerous, susceptible to explosive decomposition.
>>
>> So is the gas. It's actually much worse than hydrogen which is quite
>> explosive.
>
> Hydrogen will not explode unless there's another substance present that
> it can combine with e.g. oxygen. Liquefied acetylene is perfectly
> capable of exploding on its own.
No it's not. Acetylene combusts normally
2 H2C2 + 5 O2 -> 4 CO2 + 2 H2O.
>Notice that I described it as decomposition not combustion.
So what's the decomposition process?
Stephen
You can't call melted wax a liquefied solid? You would say it is a
liquefied ....what? Former solid?
--
Stephen
Ballina, NSW
David Hatunen
Odd you should ask since wax doesn't really melt or solidify and doesn't
partake of the solid and liquid phase. Rather it just gets softer and
softer when you heat it until it's runny; just when it can be called
"liquid" is vague.
Stephen
So LPG is a liquefied former petroleum gas, or what?
--
Stephen
Ballina, NSW
Peter Moylan
> On Sat, 09 Apr 2011 10:40:28 +1000, Peter Moylan wrote:
>
>> Prai Jei wrote:
>>
>>> No probs here. We make the distinction the other way - a substance that
>>> is in the gaseous state but is normally liquid (or solid) at room
>>> temperatore, is more correctly described as a *vapour* rather than a
>>> gas.
>> As I understand it a vapour is not a gas, but a collection of liquid
>> droplets.
>
> No. Vapour is just a gas, but it's usually mixed into the atmosphere when
> it's called a "vapor".
Yet the dictionaries seem to use the word "suspension" when defining vapour.
> Water vapor in the air is humidity. If the air
> temperature falls below the dew point the vapor condenses into tiny drops
> and become fog if it's on the ground and a cloud if it's above your head.
> The cloud you see is condensate.
Agreed - and it's that condensate that I learnt to call "vapour".
>
> But I've given up trying to maintain this distinction in public.
I wonder if this is pondian. The distinction I knew about was the
distinction between vapour and gas. I see, however, that a number of
web pages define it your way.
Prai Jei
continuum:
> On Sat, 09 Apr 2011 21:21:47 +0100, Prai Jei wrote:
>
>> Bertel Lund Hansen set the following eddies spiralling through the
>> space-time continuum:
>>
>>> Prai Jei skrev:
>>>
>>>> Butane is the most common example of a gas that can be liquefied in
>>>> this way. Acetylene will also liquefy under pressure, but the liquid
>>>> is extremely dangerous, susceptible to explosive decomposition.
>>>
>>> So is the gas. It's actually much worse than hydrogen which is quite
>>> explosive.
>>
>> Hydrogen will not explode unless there's another substance present that
>> it can combine with e.g. oxygen. Liquefied acetylene is perfectly
>> capable of exploding on its own.
>
> No it's not. Acetylene combusts normally
>
> 2 H2C2 + 5 O2 -> 4 CO2 + 2 H2O.
I'm not denying that that can happen. But when there's no O2 about you can
still get an explosion from the acetylene itself.
>>Notice that I described it as decomposition not combustion.
>
> So what's the decomposition process?
C2H2 = 2C + H2
The reaction is exothermic due to the release of the high energy of the
carbon-carbon triple bonds. Mechanical shock is enough to initiate the
reaction which results in an explosion.
The hydrocarbon prismane, C6H6 (isomeric with benzene) is liquid under
ordinary conditions, and just as susceptible to explosive decomposition.
Although the carbon-carbon bonds are all single, they are bent well away
from their natural angles to form the framework of a triangular prism, so
introducing strain which requires energy to set up. The breakup of this
molecule is highly exothermic as this energy then gets released.
Cubane, C8H8, has less strain than prismane and is quite stable. Going the
other way, tetrahedrane, C4H4, has so much strain that the substance has
never been synthesized. (Tetrahedrane derivatives are known, but not the
basic molecule itself.)
David Hatunen
> David Hatunen wrote:
>> On Sat, 09 Apr 2011 10:40:28 +1000, Peter Moylan wrote:
>>
>>> Prai Jei wrote:
>>>
>>>> No probs here. We make the distinction the other way - a substance
>>>> that is in the gaseous state but is normally liquid (or solid) at
>>>> room temperatore, is more correctly described as a *vapour* rather
>>>> than a gas.
>>> As I understand it a vapour is not a gas, but a collection of liquid
>>> droplets.
>>
>> No. Vapour is just a gas, but it's usually mixed into the atmosphere
>> when it's called a "vapor".
>
> Yet the dictionaries seem to use the word "suspension" when defining
> vapour.
Dictionaries address common usage.
>> Water vapor in the air is humidity. If the air temperature falls below
>> the dew point the vapor condenses into tiny drops and become fog if
>> it's on the ground and a cloud if it's above your head. The cloud you
>> see is condensate.
>
> Agreed - and it's that condensate that I learnt to call "vapour".
I know. And I'm not innocent, either.
>> But I've given up trying to maintain this distinction in public.
>
> I wonder if this is pondian. The distinction I knew about was the
> distinction between vapour and gas. I see, however, that a number of
> web pages define it your way.
I'm inclined to think of gas when it's in a sort of pure state, right out
of the Dewar or propane bottle, while a vapor is a gas mixed in with
other gases. It seems as if I usually hear the word "vapor" in respect to
"vapor pressure". Of course, just to muddy the waters, liquid water has a
vapor pressure.
I could be a little vaguer, I suppose. It seems to be one of those things
of scientific terminology as opposed to popular terminology.
David Hatunen
> So LPG is a liquefied former petroleum gas, or what?
It's the label on the side of a tanker.
Stephen
> On Sun, 10 Apr 2011 12:25:32 +1000, Stephen wrote:
>
>> So LPG is a liquefied former petroleum gas, or what?
>
> It's the label on the side of a tanker.
>
I got a laugh, thanks.
--
Stephen
Ballina, NSW
David Hatunen
Interesting. Have you got an on-line cite for that?
Garrett Wollman
David Hatunen <dhat...@cox.net> wrote:
>I'm inclined to think of gas when it's in a sort of pure state, right out
>of the Dewar or propane bottle, while a vapor is a gas mixed in with
>other gases. It seems as if I usually hear the word "vapor" in respect to
>"vapor pressure". Of course, just to muddy the waters, liquid water has a
>vapor pressure.
Solid water has a vapor pressure, too, even at conditions regularly
encountered by humans, some even not too far from where you are.
I gather that a non-negligible fraction -- maybe even more than half?
-- of the seasonal ice in the Arctic is lost this way.
-GAWollman
David Hatunen
> In article <intkga$1k3$2...@xen1.xcski.com>, David Hatunen
> <dhat...@cox.net> wrote:
>>I'm inclined to think of gas when it's in a sort of pure state, right
>>out of the Dewar or propane bottle, while a vapor is a gas mixed in with
>>other gases. It seems as if I usually hear the word "vapor" in respect
>>to "vapor pressure". Of course, just to muddy the waters, liquid water
>>has a vapor pressure.
>
> Solid water has a vapor pressure, too, even at conditions regularly
> encountered by humans, some even not too far from where you are.
Not much solid water around here, except in my kitchen. Actually, we just
had some unseasonably cold weather and I believe the top of Mt Lemmon has
snow and ice; it's about a 45 minute drive even though a crow could fly
it in about 15 miles or so.
> I gather that a non-negligible fraction -- maybe even more than half? --
> of the seasonal ice in the Arctic is lost this way.
I recall some photos in the old LIFE magazine taken in Alaska. One showed
a woman hanging out her wash even though it froze almost instantly. The
cutline said that the laundry would be dry in a few days.
John Holmes
I'm sure I was taught that same distinction at some point. It wasn't
until learning about partial pressures and the gas law in later high
school chemistry that the distinction (ahem) evaporated.
--
Regards
John
for mail: my initials plus a u e
at tpg dot com dot au
Bertel Lund Hansen
> I recall some photos in the old LIFE magazine taken in Alaska. One showed
> a woman hanging out her wash even though it froze almost instantly. The
> cutline said that the laundry would be dry in a few days.
It will. If I had had somewhere outside to hang my laundry, I
wouldn't worry if it was freezing. I have done that before, and
my mother did it when I was a child.
If you take down the laundry too soon, you must be careful not to
break it, but if you wait long enough, it is dry.
--
Bertel, Denmark
Mike Barnes
>On Mon, 11 Apr 2011 06:04:11 +0000, Garrett Wollman wrote:
>>
>> Solid water has a vapor pressure, too, even at conditions regularly
>> encountered by humans, some even not too far from where you are.
>
>Not much solid water around here, except in my kitchen.
If you use open trays for making ice cubes, you'll see that the cubes
shrink visibly within a few weeks.
--
Mike Barnes
Cheshire, England
bob
wrote:
> Prai Jei wrote:
> > No probs here. We make the distinction the other way - a substance that is
> > in the gaseous state but is normally liquid (or solid) at room temperatore,
> > is more correctly described as a *vapour* rather than a gas.
>
> As I understand it a vapour is not a gas, but a collection of liquid
> all, but water vapour. (There's also gaseous steam present, but it's
> invisible.) Ditto for clouds.
Thermodynamics of fluids and phase change is my day job, I'll try not
to be too technical, but here goes...
The terms "vapour" and "gas" are used by different people to refer to
the same thing, although some people like to make a distinction
between them (and I can think of two different distinctions that could
be used). Basically everything that is not a solid is a fluid. The
difference between a solid and a fluid is that a solid can support
shear stress without movement (ie it doesn't flow). Within the
category "fluid" there exist "gas", "vapour" and "liquid" (setting
plasmas asside for the advanced class). For every fluid (well the
common ones certainly, odd long chain organic stuff often behaves
strangely, but I'll not go there just now) there exists a critical
pressure. Above this critical pressure, if I add or remove heat, the
temperature will change. The density may also change, but the fluid
will always remain continuous, with nothing like droplets or bubbles
present. below this pressure, things behave differently. There is a
certain point, which is dependent on the pressure, where if I add or
remove heat, a distinct phase change occurs, with liquid changing to
gas, or vice versa. Both can exist in equilibrium together, with a
distinct boundary between the phases. In this situation, if I add or
remove heat, it will not change the temperautre of the substance, but
it will change the relative proportions of liquid and gas (until it
ends up all as one or the other).
So, getting back to the tricky words "vapour" and "gas". There are
some people who say that the term "gas" only applies to fluids above
their critical pressure. Anything below that is either a liquid or a
vapour (or a mixture of the two). There are other people who argue
that anything above critical pressure is a gas, and anything below the
critical pressure that is all in the gas phase is a "gas", and
anything that is in the two-phase state is a "vapour". There are yet
more people who don't like to use the word "vapour" at all because
it's too confusing (but still use liquid and gas). Of course in
different fields, different styles catch on.
What is consistently true, however, is that in the two-phase region
where there are liquid droplets in a gas, or gas bubbles in a liquid,
the term "vapour" is never used for the liquid phase, only ever for
the gas phase. As water vapour is optically indistinguishable from
air [1], you can not "see" water vapour or steam or water in the gas
phase (depending on your chosen terminology). You can see liquid
water that condenses from water vapour/steam/gas phase water as it
cools down (or with certian pressure changes), and that's what you see
above your kettle, or floating in the sky, or in front of your mouth
in wintertime. What you are seeing is not "vapour", however [2].
[1] in the sort of conditions one might expect to find water vapour
and steam in the ordinary home or office environment
[2] a case could be made, from the "descriptionist" view of language
usage that a significant minority of people do use the term "vapour"
for these situations because of inadequate teaching by parents and
teachers, and it therefore could be taken to be an alternative
meaning. Given the ammount of disagreement over the correct use of
the word "vapour" anyway, I'm not too sure I would object too
strongly, so long as you don't make a fool out of yourself by tring ot
use it in a scientific/engineering context.
Robin
bob
> On Fri, 08 Apr 2011 11:42:30 +0000, Mardon wrote:
>
> [...]
>
> > I know a gas can become a liquid under certain conditions of temperature
> > and pressure. That said, I don't think it would ever be correct to use
> > "liquid" as an adjective to describe a gas. What I think is acceptable
>
> I reckon the difficulty arises from common use of the word 'gas" to
> signify not only the physical state of matter, but also a particular
> substance, which may or may not be in gaseous form (in the U.S., one
> fuels automobiles with "gas", which is short for gasoline).
Indeed. "Gas" for petrolium fuels can be used to cover a very wide
variety of substances, from methane to decane and points in between,
with much inconsistency. There exist the seemingly inconsistently
named "liquefied natural gas" and "liquefied petrolium gas" (two
different things, I believe the former is mostly methane, the latter
mostly propane), as well as the USian usage of "gas" for liquid fuel
often used in spark ignition car engines.
Robin
David Hatunen
Ice sublimation is the reason for what is called "freezer burn",
affecting frozen foods.
Prai Jei
continuum:
>> The reaction is exothermic due to the release of the high energy of the
>> carbon-carbon triple bonds. Mechanical shock is enough to initiate the
>> reaction which results in an explosion.
>
> Interesting. Have you got an on-line cite for that?
Don't know if it's on-line, just been rummaging through some of my old
organic chemistry textbooks. Checking W*******a now ... Yes, check out the
last section, "Safety and handling", at
http://en.wikipedia.org/wiki/Acetylene
As with most organic reactions, it is not as simple as I indicated above, a
variety of products are formed by the self-reaction of acetylene.
Interesting that one of the products is a dimer, vinylacetylene,
CH2=CH-C≡CH. There are not many stable hydrocarbons of formula C4H4 -
cyclobutadiene decomposes rapidly and tetrahedrane is non-existent.
R H Draney
>
>If you use open trays for making ice cubes, you'll see that the cubes
>shrink visibly within a few weeks.
I wish you'd been around to explain this to my stepfather, and the corollary
that if you leave them long enough they'll vanish altogether....r
Mike Lyle
But in the Andes, they preserve potatoes by freeze-drying in the open
air. I understand these naturally lyophilized slices can even be a
delicacy.
--
Mike.
David Hatunen
> David Hatunen set the following eddies spiralling through the space-time
> continuum:
>
>>> The reaction is exothermic due to the release of the high energy of
>>> the carbon-carbon triple bonds. Mechanical shock is enough to initiate
>>> the reaction which results in an explosion.
>>
>> Interesting. Have you got an on-line cite for that?
>
> Don't know if it's on-line, just been rummaging through some of my old
> organic chemistry textbooks. Checking W*******a now ... Yes, check out
> the last section, "Safety and handling", at
> http://en.wikipedia.org/wiki/Acetylene
Ah. I missed that when I read that article.
occam
> On Apr 8, 12:42 pm, Mardon <mgb72...@hotmail.com> wrote:
>> The Globe and Mail's iPhone App contains an article this morning about the
>> Fukushima nuclear plant. In that article there is a sentence that begins:
>>
>> "A blast of liquid gas stemmed a leak this week..."
>>
>> and pressure. That said, I don't think it would ever be correct to use
>> "liquid" as an adjective to describe a gas. What I think is acceptable are
>> workers used a product like this and that the Globe & Mail author
>> substituted the generic term "gas" for the actual name of the element that
>> was used. Is it proper usage to do so? I would think not, since that
>> seems to lead to an oxymoron.
>
> Surely it is a typo for "liguid glass".
No, I do not think it is a typo. What is probably better phrase is
'liquified gas'. Yes, liquid nitrogen/hydrogen would also be better.
Peter Duncanson (BrE)
It's either a typo or other mistake. The reports from the power plant
company (TEPCO) refer to the use of "liquid glass" to seal a leak.
John Holmes
>
> Thermodynamics of fluids and phase change is my day job, I'll try not
> to be too technical, but here goes...
>
> The terms "vapour" and "gas" are used by different people to refer to
> the same thing, although some people like to make a distinction
[snip very good explanation]
Now, that makes a lot of sense. Thanks, Robin.