In a process on a system, the initial pressure and volume are equal to the final pressure and volume.

Question

Philoid · Accepted Answer

From ideal gas equation, we know that

PV=nRT

Where P=pressure

V=volume

n=number of moles

R=gas constant

T=temperature

If P_iV_i=P_fV_f

Then nRT_i=nRT_f

∴ T_i=T_f

Since the initial state of the system (P_i, V_i, T_i) is equal to final state of the system (P_f, V_f, T_f), initial and final internal energy will also be equal as internal energy is a state variable.