What is the effect of increase in concentration of Zn²⁺ ions on the electrode potential of zinc electrode ( ${\mathrm{E}}_{{\mathrm{Zn}}^{+2}/\mathrm{Zn}}$ ) ?

According to Nernst equation,

${\mathrm{E}}_{{\mathrm{Zn}}^{+2}/\mathrm{Zn}}$ $={\mathrm{E}}_{{\mathrm{Zn}}^{2+}/\mathrm{Zn}}^{°}-\frac{\mathrm{RT}}{2\mathrm{F}}\ln \frac{1}{[ {\mathrm{Zn}}^{2+ }]}$

Hence, electrode potential will increase with increase in concentration of  ${\displaystyle Z{n}^{2+}}$ions