$7$ Consider the electrode reaction $O+neR.$ Under the conditions that $C_O^{**}=C_R^{**}=1mM,k^0={10}^{-7}c\frac{m}{s},=0\mathrm{.}3,$ and $n=1$ :

$($a$)$ Calculate the exchange current density, $j_0=\frac{i_0}{A},$ in $\frac{A}{c}{m}^2.$

$($b$)$ Draw a current density$-$overpotential curve for this reaction for current densities up to $600\frac{A}{c}{m}^2$ anodic and cathodic. Neglect mass$-$transfer effects.

$($c$)$ Draw $log|j|$ vs$.$ curves $($Tafel plots$)$ for the current ranges in $($b$).$