Suppose you add 45 J of heat to a system, let it do 10. J of expansion work, and then return the system to its initial state by cooling and compression. Which statement is true for this process?

Question

Quizplus · Accepted Answer

The first law of thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system. In this case, ΔU = Q - W = 45 J - 10 J = 35 J. However, since the system is returned to its initial state, the final internal energy is equal to the initial internal energy, so ΔU = 0. Therefore, 0 J = 35 J, which means that the change in internal energy for this process is zero (choice D). Choices A and B are not relevant to this process, and while choice C is true in general, it is not necessary for answering this specific question.

Suppose You Add 45 J of Heat to a System Δ\DeltaΔ

Suppose You Add 45 J of Heat to a System $\Delta$