The standard electrode potentials, E⊖E^\ominusE⊖, for two redox couples are shown below:
V3+(aq)+e−→V2+(aq)E⊖=−0.26 V \text{V}^{3+}(\text{aq}) + \text{e}^- \rightarrow \text{V}^{2+}(\text{aq}) \quad E^\ominus = -0.26\text{ V} V3+(aq)+e−→V2+(aq)E⊖=−0.26 V Fe3+(aq)+e−→Fe2+(aq)E⊖=+0.77 V \text{Fe}^{3+}(\text{aq}) + \text{e}^- \rightarrow \text{Fe}^{2+}(\text{aq}) \quad E^\ominus = +0.77\text{ V} Fe3+(aq)+e−→Fe2+(aq)E⊖=+0.77 VWhat is the standard electromotive force (EMF) of the cell represented by:
Pt(s)∣V2+(aq),V3+(aq)∣∣Fe3+(aq),Fe2+(aq)∣Pt(s) \text{Pt}(\text{s})|\text{V}^{2+}(\text{aq}), \text{V}^{3+}(\text{aq})||\text{Fe}^{3+}(\text{aq}), \text{Fe}^{2+}(\text{aq})|\text{Pt}(\text{s}) Pt(s)∣V2+(aq),V3+(aq)∣∣Fe3+(aq),Fe2+(aq)∣Pt(s)+0.51 V+0.51\text{ V}+0.51 V
−1.03 V-1.03\text{ V}−1.03 V
+1.03 V+1.03\text{ V}+1.03 V
−0.51 V-0.51\text{ V}−0.51 V