kamilio
Oct22-09, 11:12 AM
1. The problem statement, all variables and given/known data
From the perspective of corrosion...Gold and Copper II are joined together and immersed in a 1Molar HCl solution. What possible half-cell reactions and full cell reactions can occur? Which one is most likely to proceed?
2. Relevant equations
Half-cell potentials for
Au^{3+} + 3e^- \rightarrow Au(s) = 1.5V
Cl_2(g) + 2e^- \rightarrow 2Cl^- = 1.36V
Cu^{2+} + 2e^- \rightarrow Cu(s)=0.34V
2H^+ + 2e^- \rightarrow H_2(g)=0V
3. The attempt at a solution
The metals are exposed to hydrogen and chloride ions. Gold is the most noble and will not oxidize. The hydrogen will not oxidize copper because copper is cathodic wrt hydrogen. For the same reason, hydrogen cannot oxidize gold. Gold will oxidize copper but I don't know the hydrogen ions will steal the incoming electrons from copper and reduce to hydrogen gas.
From the perspective of corrosion...Gold and Copper II are joined together and immersed in a 1Molar HCl solution. What possible half-cell reactions and full cell reactions can occur? Which one is most likely to proceed?
2. Relevant equations
Half-cell potentials for
Au^{3+} + 3e^- \rightarrow Au(s) = 1.5V
Cl_2(g) + 2e^- \rightarrow 2Cl^- = 1.36V
Cu^{2+} + 2e^- \rightarrow Cu(s)=0.34V
2H^+ + 2e^- \rightarrow H_2(g)=0V
3. The attempt at a solution
The metals are exposed to hydrogen and chloride ions. Gold is the most noble and will not oxidize. The hydrogen will not oxidize copper because copper is cathodic wrt hydrogen. For the same reason, hydrogen cannot oxidize gold. Gold will oxidize copper but I don't know the hydrogen ions will steal the incoming electrons from copper and reduce to hydrogen gas.