Question

Does the pressure affect the cell potential?

Answer 1

1. Gibbs's free energy determines the voltage of an electrochemical cell. Gibb's free energy is given as:

$∆\mathrm{G}=-\mathrm{nFE}$, where $\mathrm{n}$is the number of moles and $\mathrm{F}$is the Faraday's constant.

2. For Gas pressure,

$∆\mathrm{G}=∆\mathrm{G}°-\mathrm{RTlnQ}$, where $\mathrm{Q}$ is the reaction quotient.

For a reaction $\mathrm{A}\rightleftharpoons \mathrm{B}\hspace{0.17em}+\mathrm{C}$

$\mathrm{Q}=\frac{{\mathrm{P}}_{\mathrm{B}}{\mathrm{P}}_{\mathrm{C}}}{{\mathrm{P}}_{\mathrm{A}}}$

where ${\mathrm{P}}_{\mathrm{A}},{\mathrm{P}}_{\mathrm{B}}\mathrm{and}{\mathrm{P}}_{\mathrm{C}}$ are the pressure of reactant A and products B and C.

Therefore, the pressure affects the cell potential.