Question

Determine the standard reduction potential for the half cell reaction, $Cl _{2}+2 e^{-} \rightarrow 2 Cl ^{-} $
given, $Pt ^{2+}+2 Cl ^{-} \rightarrow Pt + Cl _{2}, E_{\text {cell }}^{\circ}=-0.15 \,V $
$Pt ^{2+}+2 e^{-} \rightarrow Pt , E^{\circ}=1.20 \,V $

• A. 1.05 V
• B. -1.05 V
• C. -1.35 V
• D. 1.35 V

Answer 1

Answer: (D)

$ Pt + Cl _{2} \rightarrow Pt ^{2+}+2 Cl ^{-} ; \,\,\,\, E_{ Cell }^{\circ}=0.15 \,V \,\,\,\, (i)$

$ Pt ^{2+}+2 e^{-} \rightarrow Pt ; \,\,\,\,\, E^{\circ} Cell =1.20\, V \,\,\,\, (ii) $

Addition, $Cl _{2}+2 e^{-} \rightarrow 2 Cl ^{-} ; \,\,\,\,\, E^{\circ}=0.15+1.20=1.35 \,V $