Question

The first law of thermodynamics states that . Is this also a statement of the principle of conservation of energy?

Answer 1

B. Should be your answer.

Answer 2

The correct choice is

Yes, the heat that flows into the system is used to change the internal energy of the gas and becomes work done by the piston.

According to first law of thermodynamics,

Q = W + U

where Q = heat flowing into the system

W = work done by the system

U = change in internal energy of the system

hence the total energy remains same all the time which is what the principle of conservation of energy states.