Explain how electrochemical principles are useful in letallurgy with example
Answers
The principles of metallurgy are effective in the reduction of metal ions to their respective metals in their solution (or) molten states. The reduction is carried out through electrolysis (or) using reducing elements. Such methods are based on electrochemical principles.
Mn+ + A → M + An+
Metal ion reducing Element Metal Reduced ion
These electrochemical principles are explained in
ΔG° = -nE°F
n = Number of Electrons Gained
E° = Electrode Potential of Redox Couple
The value of E0 for a metal depends on its reactivity. Thus, it differs from metal to metal. More reactive metals have high E0, whereas less reactive metals have low E0. It is difficult to reduce metals that have high E0.
If the difference between the E0 values of two metals is positive, then the value of ∆G0 will be negative.
Hence, the less reactive metal will come out of the solution and the more reactive metal will go into the solution.
An+ + B → A + Bn+
Less Metal ion More reducing Element Less Reactive Metal More Reduced ion
Ex: The reduction of copper (II) to copper in the presence of iron.
Cun+ + Fe → Cu + Fen+
Copper(II) ion Iron Copper Iron(II) ion
In a simple electrolysis process, the positive ions always move towards the negative electrode called the cathode.