Calculate the standard emf of a cell that uses the Mg/Mg2+ and Cu/Cu2+ half-cell reaction at 25°C. E o = V Write the equation for the cell reaction that occurs under standard-st…

Question

asked Aug 6, 2020 131k views

1 Answer

Nzeemin · Answer 1 · 2020-08-12T21:57:04+0000

Answer with Explanation:

We have to calculate the standard emf of a cell.

Consider
E^0_(Mg/Mg+2)=-2.37 v

E^0_(Cu/Cu+2)=0.34 V

T=
$25^(\circ)=25+273=298 K$

Anode half reaction:
$Mg(s)\rightarrow Mg+2(aq)^+2e-$

Cathode half reaction:
$Cu+2(aq)+2e-\rightarrow Cu(s)$

Overall reaction of cell :

$Mg(s)+Cu+2(aq)\rightarrow Mg+2(aq)+Cu(s)$

Cathode :The electrode which gains electrons.

Anode: The electrode which losses electrons.

We know that standard emf of the cell

E^0_(cell)=E_(cathod)-E_(Anode)

E^0_(cell)=0.34+2.37=2.71 V

Hence, the standard emf of a cell=2.71 V