An excess of liquid Hg was added to acidified solution of ions

CHEMISTRY · Subjective · AP · Chemistry · Thermodynamics and Electrochemistry · Thermodynamics and Electrochemistry

Problem

An excess of liquid Hg was added to

10^{-3}\text{M}

acidified solution of

\text{Fe}^{3+}

ions. It was found that only 5% of the ions remained as

\text{Fe}^{3+}

at equilibrium at 25°C. Calculate

E^\circ

for

2\text{Hg}|\text{Hg}_2^{2+}

at 25°C for

2\text{Hg} + 2\text{Fe}^{3+} \rightleftharpoons \text{Hg}_2^{2+} + 2\text{Fe}^{2+}

and

E_{\text{Fe}^{2+}/\text{Fe}^{3+}}^\circ = -0.77\text{V}

. (IIT 1995)