Actually, Im a newbie to the site, great to be here. But the reason that I've stumbled across this forum was this question. "How much pressure, and at what temperature can you force a gas to become a liquid? I know like condensation and all those kiddie experiments blah blah blah, but Im actually interested to learn the type of materials and equipment it would require to take an amount of gas, and condense it into enough liquid to fill a small glass. Im thinking possibly pressure chambers and an extremely low temperature would produce this. If anyone could crunch some numbers and come up with the specifications required to do this it would be awesome. -MaZe

You would simply need to look up the phase diagrams for your various gases (assuming they are pure) in order to find the pressure and/or temperature required to liquify them.

 

It is unlikely you would be able to store a gas as a liquid in a glass container for any period of time, however. The pressure required to keep gases liquified will exceed the ability of the glassware to withstand implosion.

Yep phase diagrams are the wave forward...

 

http://www.science.uwaterloo.ca/~cchieh/cact/c123/phasesdgm.html

It really depends on the gas. In very cold weather you can work with liquid butane in a class if you want (and I've done it). Similarly in very hot weather (over about 35C) ether boils as soon as you open the bottle.

For nitrogen and oxygen (and lots of others) you need to understand critical temperatures and pressures (above the critical temperature the gas will never condense to form a liquid no matter how high the pressure). For nitrogen you need to cool it below -147.1 and compress it to at least 33.5 atmospheres. Not really home experiment territory.