Introduction to Thermodynamics

Which statement accurately describes an isolated system?

• Mass can be transferred in or out, but energy cannot.

• Energy can be transferred in or out, but mass cannot.

• Neither mass nor energy can be transferred in or out.

• Both mass and energy can be transferred in or out.

What is the mathematical expression for the first law of thermodynamics for a closed system?

• ΔU = Q - W

• Q = ΔU + W

• W = Q + ΔU

• Q = W - ΔU

In a P-V diagram, if the arrow indicating a process points to the right, what does this signify about the work done?

• The work done is negative.

• The volume of the system decreases.

• The system does work on the surroundings.

• The pressure of the system increases.

According to Clausius conventions, what does a positive value for work done (W = +) indicate?

• Heat is transferred from the surroundings to the system.

• The internal energy of the system increases.

• The system does work on the surroundings.

• The surroundings do work on the system.