Question

The standard oxidation potentials of iron and silver are $+0.41\, V$ and $-0.80\, V$, respectively. The e.m.f. for cell reaction
$2 Ag _{( aq )}^{+}+ Fe _{( s )} \longrightarrow 2 Ag _{( s )}+ Fe _{( aq )}^{2+}$ is ________ $V$

Answer 1

Reduction potential of Fe and Ag electrodes are
$Fe _{(\text {aq })}^{2+}+2 e ^{-} \longrightarrow Fe _{( s )}, E ^{ \circ}=-0.41\, V$
$Ag _{( aq )}^{+}+ e ^{-} \longrightarrow Ag _{( s )} ; E =+0.80\, V$

$E _{\text {cell }}^{\circ}= E _{\text {cathode }}^{\circ}- E _{\text {anode }}^{\circ}=+0.80-(-0.41)$
$=1.21\, V$