An ideal gas undergoes the process a→b→c→a shown in the pV diagram.In the figure,P_a = P_c = 240 kPa,V_b = V_c = 40 L,V_a = 15 L,and P_b = 400 kPa.How much internal (thermal)energy is gained by the gas in this a→b→c→a process?

Question

Quizplus · Accepted Answer

Internal (thermal) energy of an ideal gas is given by,
ΔU = 3/2 nRΔT
where n is the number of moles of gas and R is the gas constant.
Since the process is cyclic, the gas returns to its initial state, so ΔU = 0.
Therefore, the internal (thermal) energy gained by the gas in this process is zero. 
The correct answer is option C.

An Ideal Gas Undergoes the Process A→b→c→a Shown in the PV