Consider the following data at 298 K

CHEMISTRY · Multi-part · A Level · Chemistry · Electrode potentials · Electrode potentials

Problem

Consider the following data at 298 K. The first value is given as a standard oxidation potential; the rest are standard reduction potentials.

\text{Zn} \rightarrow \text{Zn}^{2+} + 2e^-

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

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

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

\text{Ag}^{+} + e^- \rightarrow \text{Ag}

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

(a) Calculate the standard cell potential,

E^\circ_{\text{cell}}

, for a galvanic cell that employs the zinc and iron half-reactions. (b) Using the value from part (a) and

n = 2\,\text{mol}\,e^-

, determine the sign of

\Delta G^\circ

for the overall reaction at standard conditions.