Question

Atoms A and X are fictional atoms. Suppose that the standard potential for the reduction of X^2+ is +0.51 V, and the standard potential for the reduction of A^2+ is -0.33. Find the standard potential for an electrochemical cell with the cell reaction that follows.

Answer 1

If you are given the standard potential for the reduction of X^2+ is +0.51 V, and the standard potential for the reduction of A^2+ is -0.33, just add the two. The standard potential for an electrochemical cell with the cell is 0.18V

Answer 2

Answer: Thus the standard potential for an electrochemical cell with the cell reaction that follows is 0.84 V.

Explanation:

Standard potential for an electrochemical cell is given by:

$E^0{cell}$ = standard electrode potential =$E^0{cathode}-E^0{anode}$

The $E^0$ values have to be reduction potentials.  

Given: Reduction potential for atom X:

$E^o_{X^{2+}/X}=+0.51V$

$E^o_{A^{2+}/A}=-0.33V$

The element A with negative reduction potential will lose electrons undergo oxidation and thus act as anode.The element X with positive reduction potential will gain electrons undergo reduction and thus acts as cathode.

$X^{2+}+A\rightarrow X+A^{2+}$

$E^0{cell}$ = standard electrode potential =$E^0{cathode}-E^0{anode}=+0.51-(-0.33)=0.84V$

Thus the standard potential for an electrochemical cell with the cell reaction that follows is 0.84 V.