Question Detail
Question
If a reaction has ΔH < 0 and ΔS < 0, under what conditions is it spontaneous?
Correct Answer
Option A is the correct answer.
Detailed Explanation
With ΔH negative (favorable) and ΔS negative (unfavorable), spontaneity depends on temperature. The equation ΔG = ΔH - TΔS shows that at low temperatures, the favorable ΔH term dominates, making ΔG negative. At high temperatures, the unfavorable -TΔS term becomes too large.
Hint
Analyze ΔG = ΔH - TΔS. At low T, the -TΔS term is small; at high T, it is large.