(a) Write the reactions for the discharge and charge of a nickel-cadmium
(nicad) rechargeable battery. (b) Given the following reduction potentials,
calculate the standard emf of the cell:
$$
\begin{array}{r}{\operatorname{Cd}(\mathrm{OH})_{2}(s)+2 \mathrm{e}^{-}
\longrightarrow \mathrm{Cd}(s)+2 \mathrm{OH}^{-}(a q)} \\\
{E_{\mathrm{red}}^{\circ}=-0.76 \mathrm{V}}\end{array}
$$
$$
\begin{array}{r}{\mathrm{NiO}(\mathrm{OH})(s)+\mathrm{H}_{2}
\mathrm{O}(l)+\mathrm{e}^{-} \longrightarrow
\mathrm{Ni}(\mathrm{OH})_{2}(s)+\mathrm{OH}^{-}(a q)} \\\
{E_{\mathrm{red}}^{\circ}=+0.49 \mathrm{V}}\end{array}
$$
(c) A typical nicad voltaic cell generates an emf of \(+1.30 \mathrm{V}\) . Why
is there a difference between this value and the one you calculated in part
(b)? (d) Calculate the equilibrium constant for the overall nicad reaction
based on this typical emf value.