Why is it that gas compression leads to an increase in temperature under adiabatic process?

m25

Why is it that gas compression leads to an increase in temperature under adiabatic process?
It just does not seem to fit with the PV=nRT equation? And since adiabatic process neither loses or gain heat, how is it even possible that the temperature increases?

Jumb0

5+ Year Member
U = Q + W
Q = Zero in this case, so U = W
The gas is compressed, so its work function is positive.
That means U is also positive. The internal energy of the gas increased.
The internal energy of an ideal gas is given by U = 3nRT/2
U and T are directly proportional. Therefore, as U increases, T will increase too. ...
7+ Year Member
Adiabatic means the system can't exchange heat with its surroundings, not that the temperature can't increase.
So, with PV=nRT, if you increase the pressure (through compression) then something on the other side of the equation has to increase as well. R is a constant, and you're not adding more moles of gas, so it has to be T that increases.

• getfat
OP
M

m25

Adiabatic means the system can't exchange heat with its surroundings, not that the temperature can't increase.
So, with PV=nRT, if you increase the pressure (through compression) then something on the other side of the equation has to increase as well. R is a constant, and you're not adding more moles of gas, so it has to be T that increases.
But in that case, isn't volume V also decreasing because it's a compression?