Ok this one has been getting me,

 

Does the tempature of a gas change if the presure is changed?

 

I could sware i heard it many times before but my chem teacher says that it does not.

 

some one cair to explain

ask your teacher how the principal behind a Diesel engine works

 

the top sentence here: http://en.wikipedia.org/wiki/Gas_compressor

 

this May help too: http://en.wikipedia.org/wiki/Heat_of_vaporization

In an isothermal expansion, no. But that's a specific case. Point your chem teacher to the ideal gas law, PV=nRT and ask what can change if volume is held constant.

this is good too: http://en.wikipedia.org/wiki/Entropy

and a chem teacher is required to teach this also.

a chemistry teacher not familiar with the ideal gas law? somethings up there. sure he's not just a biology teacher drafted in to cover a shortage?

ok well after talking to him i guess i missed a big part.

 

in the lab we did the volume changed... so we had a plunger and we pushed it to different volumes and the pressure increased that way, at the time i guess it did not mater. guess it did anyway.

maybe your teacher tryed to explain the coolant systems in simple words, maybe too simple for you get it right?

Okay, consider having a gas inside of a piston.

 

Suppose that the piston moves inward, so that the atoms aer slowly compressed into a smaller space. What happpens when an atom hits the moving piston? Evidentily it picks up speed from the collision. You can try it by boucning a ping-pong ball from a forward-movin paddle. An atoms happens to be standing still adn ths piston hits it, it will surely move. So the atoms are 'hotter' when they come away from the piston then they were befroe they struck it. Therefore all the atoms which are in the vessel will have picked up speed. This means that, when we compress a gagas slowly, the temeprature will increase. So under slow compression a gas will increase in tremperature, and under slow expansion it will decrease in temperature.