When a fixed amount of ideal gas goes through an adiabatic expansion,
A) its internal (thermal) energy does not change.
B) the gas does no work.
C) no heat enters or leaves the gas.
D) its temperature cannot change.
E) its pressure must increase.

Question

Quizplus · Accepted Answer

In an adiabatic process, no heat enters or leaves the system, which is the defining characteristic of such a process. This is why option C is correct. Options A, B, D, and E are incorrect because in an adiabatic expansion of an ideal gas, its internal energy decreases (since work is done by the gas), the gas indeed does work, its temperature decreases (due to the decrease in internal energy), and its pressure decreases (as it expands).

When a Fixed Amount of Ideal Gas Goes Through an Adiabatic