Answer with Explanation:
We have to calculate the standard emf of a cell.
Consider [tex]E^0_{Mg/Mg+2}=-2.37 v[/tex]
[tex]E^0_{Cu/Cu+2}=0.34 V[/tex]
T=[tex]25^{\circ}=25+273=298 K[/tex]
Anode half reaction:[tex]Mg(s)\rightarrow Mg+2(aq)^+2e-[/tex]
Cathode half reaction:[tex]Cu+2(aq)+2e-\rightarrow Cu(s)[/tex]
Overall reaction of cell :
[tex]Mg(s)+Cu+2(aq)\rightarrow Mg+2(aq)+Cu(s)[/tex]
Cathode :The electrode which gains electrons.
Anode: The electrode which losses electrons.
We know that standard emf of the cell
[tex]E^0_{cell}=E_{cathod}-E_{Anode}[/tex]
[tex]E^0_{cell}=0.34+2.37=2.71 V[/tex]
Hence, the standard emf of a cell=2.71 V
