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Chemical Equilibria
Redox Electron Transfer and Half-Reactions
Description
Redox reactions involve the transfer of electrons from one species to another. In this type of reaction, electrons are not shared between atoms. They move from the species that loses them to the species that gains them.
The species that loses electrons is the reducing agent, also called the reduc...
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Transcript
氧化还原反应涉及电子从还原剂向氧化剂的转移。
氧化态升高的物质被氧化,而氧化态降低的物质被还原。
因此,氧化还原反应的热力学通过移动的电子来表示。
氧化还原反应的自由能变化为 –nFE,其中 n 为电子数,F 为法拉第常数,E 为电化学势。
然而,反应的吉布斯自由能是反应物和产物浓度的函数。
将 ΔG 代入该方程可得到其与电化学势的关系,再除以 –nF 即得到能斯特方程。
由于在平衡状态下 ΔG 为零,因此 E 必须为零,此时反应商等于平衡常数。
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