Question

Using the E¤ value of A and B pridict whichis better for coating the surface of iron . [E¤(fe+2/fe)=-.44V] to prevent corrosion why?
Given: E¤(A+2|A)=-2.37V : E¤(B+2|B)=-.14V

Answer 1

Corrosion is basically a phenomenon of oxidation of iron. Thus, we must consider the oxidation potentials of all the elements. Whichever element A or B has a higher oxidation potential than that of Fe, will oxidise faster than iron (sacrificial oxidation), thus protecting iron from getting corroded.

Oxidation potential of Fe = 0.44 V

Oxidation potential of A = 2.37 V

Oxidation potential of B = 0.14 V

Since, A has a higher oxidation potential than that of iron, it can be used for coating the surface of iron.