Pizza Rolls review number 6

[Parker Smith]

For number 6a of the pizza rolls review, they said both the entropy and the internal energy change of the process remains at 0. Why is that?

[Rachel Yu 1G]

Because the whole reaction results in the substance back in its initial state. Both internal energy and entropy are state functions meaning that the intermediate steps in this reaction do not matter, only the initial and ending conditions. Since the initial and final states are the same, entropy and internal energy will be 0.

[Junwei Sun 4I]

Because the initial and final states are the same. Both internal energy and entropy are state functions, which means they do not depend on the path taken. In this problem eventually pressure and volume are restored to their initial states, therefore deltaU and deltaS are both zero.