Chapter 19, Problem 99IAE

Interpretation Introduction

Interpretation:

It should be shown that for nonstandard conditions the temperature variation of cell potential is $E(T_1)-E\left(T_2\right)=\left(T_1-T_2\right)\frac{\left({\Delta }_r{S}^0-R\ln Q\right)}{zF}$.

Also, the value of Q, Δ_rH⁰, Δ_rS⁰ for the reaction should be calculated and K for the two temperatures should be calculated.

Equilibrium concentrations of the species at 50.0 ⁰C should be calculated.

Concept introduction:

The value of ${\Delta }_{r}G$ is related to ${\Delta }_r{G}^0$ as follows:

${\Delta }_{r}G={\Delta }_r{G}^0+RT\ln Q$

Here, R is Universal gas constant, T is temperature and Q is reaction quotient.

The value of ${\Delta }_r{G}^o$ is related to ${\Delta }_r{H}^0$ and $\Delta S^0$ as follows:

${\Delta }_r{G}^0={\Delta }_r{H}^0-T.\Delta S^0$

Here, ${\Delta }_{r}G$ is standard Gibbs free energy change, ${\Delta }_r{H}^0$ is standard enthalpy change and $\Delta S^0$ is standard entropy change.

It is related to Ecell as follows:

${\Delta }_{r}G=-zF{E}_{cell}$

Here, z is number of electron/s transferred and F is Faraday’s constant.

The Gibbs free energy change is related to equilibrium constant as follows:

${\Delta }_r{G}^0=-RT\ln K$

Here, R is Universal gas constant, T is temperature and K is equilibrium constant.