gas pressure and temperature relation

[dusty8683]

just trying to understand how/why these two are proportional. if you compress a gas all the atoms and/or molecules would have less room to move around. so does the friction between these moving objects create heat? and if when gasses are compressed they heat up... why then when they are compressed to a liquid are they extremely cold? any explanation would be helpful, even just a link that has an explanation would do. thanks

[Clausius2]

just trying to understand how/why these two are proportional. if you compress a gas all the atoms and/or molecules would have less room to move around. so does the friction between these moving objects create heat?

The temperature has nothing to do with friction, but just with colliding effects. The more pressure the less space between molecules, and then major probability of colliding each other, and then the more kinetic energy transferring, and then the more average kinetic energy, and then the more temperature, and then.... :zzz:

[da_willem]

The larger the temperature of a gas the faster the molecules will move (temperature is proportional to the average kinetic energy of the particles) and the larger the force they will excert, and the higher the pressure (pressure is the force excerted by the particles divided by the area).

[da_willem]

See also http://www.physicsforums.com/showthread.php?t=39446

My answer there was:
Microscopically the force on a container wall with some (ideal) gas in it is proportional to the average velocity (determines the rate of collisions) and momentum (determines the 'impact' of the collisions) of the molecules constituting the gas.

As you might know, pressure is a force per area. Kinetic energy is half the product of momentum and velocity. So you can easily see that pressure is proportional to the average kinetic energy and thus the temperature...