Adiabatic Process: No Energy Change but Temperature Change?

[EIRE2003]

In an Adiabatic Process no heat energy is trasferred into or out of the system so there is no energy change, BUT, there is a change in pressure, volume and temperature.

But when atoms or molecules gain/loose heat energy they vibrate more/less respectively. And the measure of the vibration of the atoms/molecules is the temperature, am I right? So my question is Why is there no energy change but a temperature change?

Thanks

 

[Andrew Mason]

In an Adiabatic Process no heat energy is trasferred into or out of the system so there is no energy change, BUT, there is a change in pressure, volume and temperature.

But when atoms or molecules gain/loose heat energy they vibrate more/less respectively. And the measure of the vibration of the atoms/molecules is the temperature, am I right? So my question is Why is there no energy change but a temperature change?

Thanks

There is an energy change. It is a change to the internal energy of the gas. The energy change is equal to the amount of work done by or to the gas.

This is an area that causes confusion. Prof. Zemansky would say that you should not talk about heat as distinct from internal energy. This is probably a good idea, but that is not yet the way thermodynamics is taught.

AM