In the activity, click on the E∘cell and Keq quantities to observe how they are related. Use this relation to calculate Keq for the following redox reaction that occurs in an electrochemical cell having two electrodes: a cathode and an anode. The two half-reactions that occur in the cell areCu2+(aq)+2e−→Cu(s) and Fe(s)→Fe2+(aq)+2e−

Respuesta :

Answer: The [tex]E^o_{cell}\text{ and }K_{eq}[/tex] of the reaction is 0.78 V and [tex]2.44\times 10^{26}[/tex] respectively.

Explanation:

For the given half reactions:

Oxidation half reaction: [tex]Fe(s)\rightarrow Fe^{2+}+2e^-;E^o_{Fe^{2+}/Fe}=-0.44V[/tex]

Reduction half reaction: [tex]Cu^{2+}+2e^-\rightarrow Cu(s);E^o_{Cu^{2+}/Cu}=0.34V[/tex]

Net reaction: [tex]Fe(s)+Cu^{2+}\rightarrow Fe^{2+}+Cu(s)[/tex]

Oxidation reaction occurs at anode and reduction reaction occurs at cathode.

To calculate the [tex]E^o_{cell}[/tex] of the reaction, we use the equation:

[tex]E^o_{cell}=E^o_{cathode}-E^o_{anode}[/tex]

Putting values in above equation, we get:

[tex]E^o_{cell}=0.34-(-0.44)=0.78V[/tex]

To calculate equilibrium constant, we use the relation between Gibbs free energy, which is:

[tex]\Delta G^o=-nfE^o_{cell}[/tex]

and,

[tex]\Delta G^o=-RT\ln K_{eq}[/tex]

Equating these two equations, we get:

[tex]nfE^o_{cell}=RT\ln K_{eq}[/tex]

where,

n = number of electrons transferred = 2

F = Faraday's constant = 96500 C

[tex]E^o_{cell}[/tex] = standard electrode potential of the cell = 0.78 V

R = Gas constant = 8.314 J/K.mol

T = temperature of the reaction = [tex]25^oC=[273+25]=298K[/tex]

[tex]K_{eq}[/tex] = equilibrium constant of the reaction = ?

Putting values in above equation, we get:

[tex]2\times 96500\times 0.78=8.314\times 298\times \ln K_{eq}\\\\K_{eq}=2.44\times 10^{26}[/tex]

Hence, the [tex]E^o_{cell}\text{ and }K_{eq}[/tex] of the reaction is 0.78 V and [tex]2.44\times 10^{26}[/tex] respectively.

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