Gibbs Free Energy
For a reaction to be spontaneous at all temperatures, which condition must be satisfied?
Select the correct option:
Solution
ΔH < 0, ΔS > 0
Spontaneity is determined by the Gibbs Free Energy change: ΔG=ΔH−TΔS. For a reaction to be spontaneous, ΔG must be negative.
- If ΔH<0 (Exothermic) and ΔS>0 (Increased entropy), then: ΔG=(−ve)−T(+ve).
- Since T (absolute temperature) is always positive, ΔG will be negative at any temperature. This ensures spontaneity under all conditions.
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About This Question
- Subject
- chemistry
- Chapter
- chemical thermodynamics
- Topic
- gibbs free energy
- Difficulty
- Medium
- Year
- 2025
Solution
Correct Answer:
ΔH < 0, ΔS > 0
Spontaneity is determined by the Gibbs Free Energy change: ΔG=ΔH−TΔS. For a reaction to be spontaneous, ΔG must be negative.
- If ΔH<0 (Exothermic) and ΔS>0 (Increased entropy), then: ΔG=(−ve)−T(+ve).
- Since T (absolute temperature) is always positive, ΔG will be negative at any temperature. This ensures spontaneity under all conditions.
This medium difficulty chemistry question is from the chapter chemical thermodynamics, covering the topic of gibbs free energy. It appeared in the 2025 exam.
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