At atmospheric pressure, carbon dioxide undergoes sublimation at -109.5°F. How does the entropy change when CO2 undergoes deposition?
D) cannot be determined
Deposition is a phase change from gas directly to solid. Less freedom of motion for the elements in a solid translates into less entropy: ΔS<0.
A) ΔS>0, incorrect, A solid arrangement of packed molecules is lower in probability than freely moving gas particles.
B) ΔS<0, correct.
C) ΔS=0, incorrect, Gas phases have greater entropy than solid phases.
D) cannot be determined, incorrect, See answer C.