## Electrochemical Principles of Metallurgy Chemistry Notes

**Electrochemical Theory of Metallergy :**

→ As we have studied earlier, how principles of thermodynamics are applied to pyrometallurgy. Similarly, some electrochemical principles are effective in the reduction of metal ions in solution or in molten state. According to electrochemical principles, the reduction in these cases are done by electrolysis or by adding some reducing elements. During the reduction of molten metal salt, the process of electrolysis is done. These methods are based on electrochemical principles which can be understood through the equation given below:

∆G° = – nFE° Cell

where, n = Number of electrons

F = Faraday constant

E° = Electrode potential of the redox couple formed in the system.

→ As we know that more reactive metals have large negative values of the electrode potential. So, their reduction is difficult. If the difference of two electrode potential values corresponds to a positive value of E° cell then the value of ∆G° will become negative in equation

∆G° = – nF°cell

→ Hence we can say if the difference of electrode potentials of two metals come positive over the value of ∆G° comes negative then the less reactive metal will come out of the solution and the more reactive metal will go to the solution e.g.,

→ In other words, we can say that the metals lying above in electrochemical series can displace the metal lying below in series from their salt solutions.