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Author Topic: What Other Gasses Combined make a Liquid  (Read 9272 times)

Offline neilep

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What Other Gasses Combined make a Liquid
« on: 18/11/2007 18:40:03 »
Dearest All,

If I combine two gasses together , lets say Hydrogen and Oxygen , I get a liquid called water !

What other gasses combined make liquids and what liquids would I get ?


 

another_someone

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What Other Gasses Combined make a Liquid
« Reply #1 on: 18/11/2007 19:50:15 »
Water is a very peculiar liquid, because it is so light (actually, a water molecule is lighter than an oxygen molecule), and is only a liquid at STP (standard temperature and pressure) because of its strong electrical dipole.

All gasses will become liquid at the right temperature and pressure, but most small molecules (of the weight comparable to the combination of two atoms that are of themselves gases) are very unlikely to become liquid at STP.

More complex, and heavier molecules, can be formed that will be liquids at STP - one such that comes to mind is chloroform, which would be from methane and chlorine - both gases at STP (taken a step further, you can get carbon tetrachloride, but this too is a liquid) - although it seems that the reaction takes place by heating at around 500C - which seems to me strange as I would have expected methane to burn as easily in chlorine gas as in oxygen.

Similarly, ethylene halides, such as ethylene dichloride and ethylene  dibromide.

I am sure a list like this can become fairly endless, but they are all far heavier than water molecules.
 

lyner

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What Other Gasses Combined make a Liquid
« Reply #2 on: 18/11/2007 23:19:55 »
It's less of a coincidence / rarity that there are not many gases that combine to form liquids than you might think.
The fact is that the liquid state is a rare one. The range of temperatures at which a substance is a liquid is small compared with the other two states. SO you wouldn't expect to find many liquids in comparison with solids and gases. If your lab were somewhere else in the universe you could find a number of metals were liquids but mercury (and water, of course) would be a gas etc etc. On the other hand, nitrogen could be a liquid, water and mercury would be solid.
 

Offline lightarrow

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What Other Gasses Combined make a Liquid
« Reply #3 on: 19/11/2007 13:40:04 »
Dearest All,

If I combine two gasses together , lets say Hydrogen and Oxygen , I get a liquid called water !

What other gasses combined make liquids and what liquids would I get ?
Your question is too generic for a simple answer.
1. With only two gasses or even more than two?
2. The gasses must be elements or can be compounds too?

With only elements and only two gasses, there are also:

H2O2 (oxygenated water)

HN3 Hydrazoic_acid:
http://en.wikipedia.org/wiki/Hydrazoic_acid

N2O4 Dinitrogen tetroxide, if you consider temperatures < 21C (it should be considered as a "gas", since standard temperature is 25C, but maybe it's ok the same for you):
http://en.wikipedia.org/wiki/Dinitrogen_tetroxide

Same consideration for Cl2O Dichlorine monoxide:
http://en.wikipedia.org/wiki/Dichlorine_monoxide

Cl2O7 Dichlorine heptoxide and other chlorine oxides.

NCl3 Nitrogen trichloride:
http://en.wikipedia.org/wiki/Nitrogen_trichloride
 

Offline sohail

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What Other Gasses Combined make a Liquid
« Reply #4 on: 19/11/2007 14:41:05 »
Water is a very peculiar liquid, because it is so light (actually, a water molecule is lighter than an oxygen molecule)

How does that work? Surely a water molecule is equivalent to an oxygen molecule plus a hydrogen atom and therefore heavier than an oxygen molecule alone?
 

paul.fr

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What Other Gasses Combined make a Liquid
« Reply #5 on: 19/11/2007 14:56:11 »
It is something to do with Avogadro's law, but i don't remember the exact details...wiki should have something.

added :

http://en.wikipedia.org/wiki/Avogadro%27s_law

Quote
Equal volumes of gases, at the same temperature and pressure, contain the same number of particles, or molecules.
« Last Edit: 19/11/2007 15:17:03 by paul.fr »
 

Offline lightarrow

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What Other Gasses Combined make a Liquid
« Reply #6 on: 19/11/2007 16:08:49 »
Water is a very peculiar liquid, because it is so light (actually, a water molecule is lighter than an oxygen molecule)

How does that work? Surely a water molecule is equivalent to an oxygen molecule plus a hydrogen atom and therefore heavier than an oxygen molecule alone?
Oxygen atom: O --> molar mass = 16
Oxygen molecule (what you find in air): O2 --> molar mass = 32
Water molecule: H2O --> molar mass = 18.
 

lyner

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What Other Gasses Combined make a Liquid
« Reply #7 on: 19/11/2007 18:28:53 »
Quote
(actually, a water molecule is lighter than an oxygen molecule)
Am I missing something? Isn't it obvious?
I know that water is odd in many respects but isn't  its molecular mass is just down to arithmetic.
 

Offline Bored chemist

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What Other Gasses Combined make a Liquid
« Reply #8 on: 19/11/2007 19:48:22 »
Yes, just arithmetic.
As lightarrow said a molecule of oxygen is two oxygen atoms stuck together.
A water molecule only has one atom of oxygen. The two hydrogens in the water don't add as much weight as the second oxygen (in O2)

O =16
O2=32
H2O=18

18<32

Incidentally oxygenated water isn't a proper translation. H2O2 is hydrogen peroxide. Oxygenated water is, like most water, a solution of oxygen- that's how fish live in ordinary water.
 

Offline lightarrow

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What Other Gasses Combined make a Liquid
« Reply #9 on: 20/11/2007 15:28:51 »

Incidentally oxygenated water isn't a proper translation. H2O2 is hydrogen peroxide. Oxygenated water is, like most water, a solution of oxygen- that's how fish live in ordinary water.
Thanks for correction.
 

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What Other Gasses Combined make a Liquid
« Reply #9 on: 20/11/2007 15:28:51 »

 

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