The standard electrode potentials for two half-cells are shown below:
Cr3+(aq)+3e−→Cr(s)E⊖=−0.74 V \text{Cr}^{3+}(\text{aq}) + 3\text{e}^- \rightarrow \text{Cr}(\text{s}) \quad E^\ominus = -0.74\text{ V} Cr3+(aq)+3e−→Cr(s)E⊖=−0.74 V Co2+(aq)+2e−→Co(s)E⊖=−0.28 V \text{Co}^{2+}(\text{aq}) + 2\text{e}^- \rightarrow \text{Co}(\text{s}) \quad E^\ominus = -0.28\text{ V} Co2+(aq)+2e−→Co(s)E⊖=−0.28 VWhat is the standard electromotive force (EMF) of the cell represented by Cr(s)∣Cr3+(aq)∥Co2+(aq)∣Co(s)\text{Cr}(\text{s}) \mid \text{Cr}^{3+}(\text{aq}) \parallel \text{Co}^{2+}(\text{aq}) \mid \text{Co}(\text{s})Cr(s)∣Cr3+(aq)∥Co2+(aq)∣Co(s)?
−0.46 V-0.46\text{ V}−0.46 V
+0.46 V+0.46\text{ V}+0.46 V
+0.64 V+0.64\text{ V}+0.64 V
−1.02 V-1.02\text{ V}−1.02 V
