Which has the higher entropy? Briefly explain why for each situation.

Question

a) 1.00 mol He (g) in a 5.00 L container or 1.00 mol He (g) in a 2.00 L container

b) 2B₂O₃(s) or 4B(s) + 3O₂(g)

Answer 1

a). 1.00 mol He(g) in a 5.00 L container will have more entropy than the same in a 2.00 L container, because there would be more "randomness" in the larger volume. There are more ways to distribute the molecules in the 5 L than there are in the 2 L.

b). Comparing a solid (B2O3) to a solid plus a gas (O2), the solid plus gas will have greater entropy because gas has greater entropy than a solid. It has greater entropy because it has more "randomness", as it can exist in many more "states" or "configurations" than a solid.