Two moles of an ideal gas have an initial Kelvin temperature Ti and absolute pressure Pi. The gas undergoes a reversible isothermal compression from an initial volume Vi to a final volume 0.5Vi.
-How much heat is exchanged with the environment? If heat is exchanged, is it absorbed or released?

Question

Quizplus · Accepted Answer

Since the gas undergoes a reversible isothermal process, the internal energy of the gas remains constant. Therefore, the heat exchanged with the environment is given by Q = W, where W is the work done on the gas during the compression. Using the formula for the work done during an isothermal process, we have W = nRTi ln(Vi/Vf), where Vf = 0.5Vi. Substituting the values given in the answer choices, we see that only choice A gives the correct expression for Q. The negative sign in front of the expression indicates that the heat is released by the gas to the environment.

Two Moles of an Ideal Gas Have an Initial Kelvin