Question

Suggest how Equation $25$-$13$could be used to determine the half-wave potential of a species reacting at an electrode.

Short answer

The required equation is$E_{appl}=E_{{}^1╱{}_2}-\frac{0.0591}{n}\log \left(\frac{i}{i_i-1}\right).$

Step-by-step solution

Step 1. Given information

The half-wave potential $\left(E_{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.}\right)$is a potential at which polarographic wave current is equal to one-half of the diffusion current $\left(i_d\right).$

Step 2. Equation of half-wave potential

$E_{appl}=E_{{}^1╱{}_2}-\frac{0.0591}{n}\log \left(\frac{i}{i_i-1}\right)$

Now, variables are

$i$is the current in ampere

$i_l$is the limiting current

$\left(E_{\raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$2$}\right.}\right)$is half-wave potential

$n$ is the number of moles of electrons per mole of the analyte.