A student wants a galvanic cell whose standard reaction free-energy change is between…

CHEMISTRY · Subjective · CBSE · Chemistry · Electrochemistry · Electrochemistry

Problem

A student wants a galvanic cell whose standard reaction free-energy change is between

-290\,\text{kJ}

and

-310\,\text{kJ}

298\,\text{K}

. The available half-cells are listed with their standard reduction potentials. A.

\mathrm{Fe}^{3+} + e^- \rightarrow \mathrm{Fe}^{2+}

E^\circ = +0.77\,\text{V}

\mathrm{Ag}^+ + e^- \rightarrow \mathrm{Ag(s)}

E^\circ = +0.80\,\text{V}

\mathrm{Zn}^{2+} + 2\,e^- \rightarrow \mathrm{Zn(s)}

E^\circ = -0.76\,\text{V}

\mathrm{Cu}^{2+} + 2\,e^- \rightarrow \mathrm{Cu(s)}

E^\circ = +0.34\,\text{V}

\mathrm{Sn}^{2+} + 2\,e^- \rightarrow \mathrm{Sn(s)}

E^\circ = -0.14\,\text{V}

298\,\text{K}

(

F = 9.65 \times 10^4\,\text{C}\cdot\text{mol}^{-1}

), indicate which two half-reactions should be combined and state the resulting

\Delta G^\circ

value (in kJ).