The heat capacity at constant volume and the heat capacity at constant pressure have different values because:
A)heat increases the internal energy at constant volume but not at constant pressure
B)heat increases the internal energy at constant pressure but not at constant volume
C)the system does work at constant volume but not at constant pressure
D)the system does work at constant pressure but not at constant volume
E)the system does more work at constant volume than at constant pressure

Question

Quizplus · Accepted Answer

At constant pressure, part of the heat added to the system is used to do work (by expanding against the external pressure), in addition to increasing the internal energy. At constant volume, the system cannot expand, so all the heat added goes into increasing the internal energy, making the heat capacity at constant volume different from that at constant pressure.

The Heat Capacity at Constant Volume and the Heat Capacity