Entropy (and free energy)

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Chemists see entropy as providing the fundamental way of deciding on the expected direction and extent of chemical change. Reactions tend to go in the direction which means that there is an overall increase in entropy - taking into account both the entropy change of the reaction system and its surroundings.

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Recently Asked Questions

• The standard entropy change of the reaction: P₄ + 5O₂ => P₄O₁₀ is -960, so entropy decreases, but still why does reaction occur spontaneously? Also, does feasibility of a reaction depend on total entropy or total entropy change? Which of the two should be positive for feasibility of a reaction? 131009
• How does the temperature of the surroundings affect the entropy change of the surroundings? 131009
• Photosynthesis is endothermic and entropically unfavourable. So why does it happen? Is the answer a) that the photons increase entropy by delivering heat as well as light or b) that the process is driven by enzymes and therefore it doesn't matter that it is unfavourable? Does the delta G having to be positive only apply to spontaneous reactions? And does that mean that enzymes are different from catalysts in that regard, or could catalysts also drive an unfavourable reaction? 170709

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Tests

• Entropy (A2)

updated: 13 January 2004