At atmospheric pressure, carbon dioxide undergoes sublimation at -109.5°F. How does the entropy change when CO2 undergoes deposition?
A. ΔS>0
B. ΔS<0
C. ΔS=0
D. cannot be determined
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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.
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