Question

Consider the following $E^{\circ}$ values
$E^{\circ}_{Fe^{3+} /Fe^{2+}} = 0.77\,V$
$E^{\circ }_{Sn^{2+} / Sn} = -0.14V$
Under standard conditions the potential for the reaction
$Sn\left(s\right) + 2Fe^{3+}\left(aq\right) \longrightarrow 2Fe^{2+}\left(aq\right) + Sn^{2+}\left(aq\right)$ is

• A. 1.68 V
• B. 0.63 V
• C. 0.91 V
• D. 1.40 V

Answer 1

Answer: (C)

$E_{cell }=E^{\circ}_{RHS} −E^{\circ}_{LHS}$
$= \left(0.77\right) - \left(-0.14\right)$
$= 0.91 \,V$