1. The problem statement, all variables and given/known data An ideal gas is taken from an initial temperature Ti to a higher final temperature Tf along two different reversible paths: Path A is at constant pressure; Path B is at constant volume. The relation between the entropy changes of the gas for these paths is a) delta S(A) > delta S(B) b) delta S(A) = delta S(B) c) delta S(A) < delta S(B) 2. Relevant equations delta S = delta Qr / T Qr = heat transferred to system while the system is going along a reversible path 3. The attempt at a solution This is one of those checkpoint questions in the chapter and the answer is given as choice a (delta S(A) > delta S(B)). I'm confused though because in this book, it says that entropy is a state variable and as such, it only depends on the endpoints and is therefore independent of the actual path taken from A to B. But here, we're taking two different paths and yet we're getting that the change in entropy going from one path is different than when we take the other path. I think the answer should be choice b (delta S(A) = delta S(B)). It would seem that if you're only dependent on the endpoints, then regardless of the path taken, if you're going from A to B in multiple ways, that the entropy should be the same for all cases. Where am I going wrong in my thought process? Thanks a lot ahead of time.