Question

Write the overall reaction and the half-cell reactions of the following cells, and clearly indicate the anode and the cathode for each cell.

c) Pb|Pb2+(0.10 M)||Cu2+(0.10 M)|Cu

d) Pb|Pb2+(0.10 M)||Zn2+(0.10 M)|Zn

e) Zn|Zn2+(0.10 M)||Fe2+(0.10 M)|Fe

f) Pb|Pb2+(0.10 M)||Fe2+(0.10 M)|Fe

Answer 1

c) Pb|Pb2+(0.10 M)||Cu2+(0.10 M)|Cu

Pb(s) ---------------> Pb^2+ (aq) + 2e^-     at anode oxidation half reaction

Cu^2+ (aq) + 2e^- ----------> Cu(s)         at cathode reduction half reaction

------------------------------------------------------------------------------------------

Pb(s) + Cu^2+ (aq) ------------> Pb^2+ (aq) + Cu(s) over all reaction

d) Pb|Pb2+(0.10 M)||Zn2+(0.10 M)|Zn

    Pb(s) -------------------> Pb^2+ (aq) + 2e^- at anode oxidation half reaction

   Zn^2+ (aq) + 2e^- ----------------> Zn(s)     at cathode reduction half reaction

--------------------------------------------------------------------------------------

Pb(s) + Zn^2+ (aq) ----------------> Pb^2+ (aq) + Zn(s) over all reaction

e) Zn|Zn2+(0.10 M)||Fe2+(0.10 M)|Fe

Zn(s) -----------------> Zn^2+ (aq) + 2e^-      at anode oxidation half reaction

Fe^2+ (aq) + 2e^- -----------> Fe(s)   at cathode reduction half reaction

--------------------------------------------------------------------------------------------------

Zn(s) + Fe^2+ (aq) ------------------> Zn^2+ (aq) + Fe(s)   over all cell reaction

f) Pb|Pb2+(0.10 M)||Fe2+(0.10 M)|Fe

Pb(s) -----------------> Pb^2+ (aq) + 2e^-      at anode oxidation half reaction

Fe^2+ (aq) + 2e^- -----------> Fe(s)   at cathode reduction half reaction

--------------------------------------------------------------------------------------------------

Pb(s) + Fe^2+ (aq) ------------------> Pb^2+ (aq) + Fe(s)   over all cell reaction