For a voltaic cell consisting of a $\mathrm{Zn}\left(\mathrm{s}\right) \overline{) {\mathrm{Zn}}^{2+}\left(\mathrm{aq}\right)}$ half -cell and an $\mathrm{Fe}\left(\mathrm{s}\right) \overline{) {\mathrm{Fe}}^{2+}\left(\mathrm{aq}\right)}$ half-cell:

Explain why the cation and anion of the salt used in the salt bridge should have approximately the same size and charge. Identify using e potassium chloride is the most common electrolyte for the salt bridge, the ionic radii of ${\mathrm{K}}^{+} (138 \mathrm{pm})$ and ${\mathrm{Cl}}^{-} (181 \mathrm{pm})$.