An ideal gas undergoes an adiabatic process while -25 J of work is done on it.What is the change in the internal (thermal)energy of the gas?

Question

Quizplus · Accepted Answer

In an adiabatic process, there is no exchange of heat energy between the system and surroundings. Therefore, the change in internal energy is equal to the negative of the work done on the system, i.e., ΔU = -W. As -25 J of work is done on the gas, the change in internal energy is +25 J. However, the answer is negative (-25 J) because the question asks for the change in thermal energy, and by convention, work done on the system is considered positive while heat absorbed by the system is considered negative. Therefore, the correct answer is (C) -25 J.

An Ideal Gas Undergoes an Adiabatic Process While -25 J