Question

For a reaction in a voltaic cell, both ΔH° and ΔS° are positive. Given the following equations for standard free energy, ΔG° =ΔH° -TΔS° ; ΔG° = -nFE° . How does the standard cell potential change with increasing temperature? Derive the equation that shows how the standard cell potential change with temperature

Answer 1

Answer:

The standard cell potential increases with increasing temperature.

Explanation:

Equatio 1: ΔG° =ΔH° -TΔS°

Equation 2:  ΔG° = -nFE°

Isolating E° in equation 2:

E° = - ΔG° / nF (Equation 3)

Substituting equation 1 in equation 3:

E° = (- ΔH° +TΔS°)/ nf

We can rearrange the equation:

E° = (ΔS°/nF) T + (ΔH°/nF)

Now it is clear that the higher the temperature, the higher the standard cell potential.