Electrochemistry of galvanic couple in an acidic solution

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SUMMARY

The discussion centers on the electrochemistry of a galvanic couple involving gold (Au) and copper (Cu) immersed in a 1M HCl solution. The half-cell potentials are provided: Au^{3+} + 3e^- → Au(s) at 1.5V, Cl_2(g) + 2e^- → 2Cl^- at 1.36V, Cu^{2+} + 2e^- → Cu(s) at 0.34V, and 2H^+ + 2e^- → H_2(g) at 0V. It is established that gold will not oxidize in this environment, and hydrogen ions cannot oxidize either metal due to their position in the electrochemical series. Consequently, no significant half-cell or full-cell reactions occur under these conditions.

PREREQUISITES
  • Understanding of half-cell potentials and their significance in electrochemistry
  • Familiarity with the electrochemical series and its implications for oxidation and reduction reactions
  • Knowledge of corrosion processes in acidic solutions
  • Basic concepts of galvanic cells and their components
NEXT STEPS
  • Study the Nernst equation and its application in calculating cell potentials
  • Research the effects of different metal combinations in galvanic cells
  • Explore corrosion prevention techniques for metals in acidic environments
  • Learn about the role of chloride ions in electrochemical reactions
USEFUL FOR

This discussion is beneficial for chemistry students, electrochemists, and corrosion engineers seeking to understand the behavior of metals in acidic solutions and the principles governing galvanic couples.

kamilio
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Homework Statement


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?

Homework 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

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.
 
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Can someone please assist me here. It's a rather simple problem but I just can't sort it through.

Hydrogen cannot oxidize gold or copper because it is lower on the emf series. Also, copper and gold cannot react because there are no Au ions in the solution (only H+ and Cl-) right? So then there aren't any half-cell/full-cell reactions?
 

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