The figure represents the spontaneous deposition of iodine in which iodine vapor,I₂(g),becomes crystalline iodine solid I₂(s): I₂(g): → I₂(s).What are the signs (+ or -)of ΔH,ΔS,and ΔG for this process?

Question

Quizplus · Accepted Answer

Since the process involves deposition (solidification) of the gas, the entropy of the system decreases. Thus, ΔS is negative. The process is exothermic, i.e., heat is released when the gas turns into solid, so ΔH is negative. For a spontaneous process, ΔG must be negative. Thus, since ΔH is negative and ΔS is negative, ΔG must be negative as well. Therefore, the correct choice is D: ΔH = -,ΔS = -,ΔG = -.

The Figure Represents the Spontaneous Deposition of Iodine in Which