Question

How is Δℰrelated to ΔG?

Short answer

A positive$\Delta \xi$ , standard reduction potential can relate to free energy $\Delta \text{G}$, . If$\Delta \xi$ is positive, then $\Delta \text{G}$will be negative and the reaction will be spontaneous and if it is vice versa the reaction will be non-spontaneous.

Step-by-step solution

The relation between ΔG and Δξ

The relation between standard reduction potential ($\Delta \xi$) and free energy ($\Delta \text{G}$) can be expressed in an equation is given below:

role="math" localid="1663575080976" $\Delta \mathrm{G}=-\mathrm{nF}\Delta \xi$

Were, ‘n’ is the number of moles of electrons

F, the faraday

The relation between ΔG and Δξ-Spontaneous reaction or not

Consider a hydrogen half-reaction given below:

${\text{2H}}^{\text{+}}{\text{+ 2e}}^{\text{-}}\rightleftarrows {\text{H}}_{\text{2}}\text{(g)}$

The reduction potential ($\Delta \xi$) of the given reaction is -0.421V, indicating that the$\Delta \text{G}$ will be positive, and the reaction will be non-spontaneous.

If the standard reduction potential is positive, then redox couples oxidized form will accept electrons and thus become reduced.