Answer :
[tex]\[ E = E^\circ - \frac{RT}{nF} \ln \left( \frac{[\text{Fe}^{2+}]}{[\text{Fe}^{3+}]} \right) \]\\2. Given standard electrode potential: \[ E^\circ = 0.77 \, \text{V} \]3. Equilibrium constant for the complexation reaction: \[ K = \frac{[\text{Fe}(\text{H}_2\text{PO}_4)_2]}{[\text{Fe}^{3+}][\text{HgPO}_4]} \]4. New concentration of Fe3+ after complex formation: \[ [\text{Fe}^{3+}]_{\text{new}}[/tex][tex]\[ E = 0.77 \, \text{V} - \frac{RT}{F} \ln \left( \frac{[\text{Fe}^{2+}]}{[\text{Fe}^{3+}]_{\text{new}}} \right) \]6. Final potential: \[ E \approx 0.5925 \, \text{V} \][/tex]
