Question

For the given reactions
Sn2+ + 2e– → Sn
Sn4+ + 4e– → Sn
the electrode potentials are;
$E^{∘}_{Sn^{2+}/Sn}=−0.140V$ and $E^{∘}_{Sn^{4+}Sn} =−0.010 V.$
The magnitude of standard electrode potential for $Sn^{4+}/Sn^{2+}$ i.e.
$E^{∘}_{Sn^{4+}/Sn^{2+}}$
is _________ × 10–2 V. (Nearest integer)

Answer 1

The correct answer is 16
$Sn→Sn^{2+}+2e− E^{∘}_{1}=0.140 V$
$Sn^{4+} + 4e^{−}→Sn$ $E^{∘}_{2}=0.010 V$
$Sn^{4+}+2e^{−}→Sn^{2+}$ $E^{∘}_{cell}$
$E^{∘}_{cell}=\frac{n_2E_{2}^{∘}+n_1E^{∘}_{1}}{n}=\frac{4(0.010)+2(0.140)}{2}$
$E^{∘}_{cell}=0.16 V=16×10^{−2} V$