# Using the E° Values of a and B, Predict Which is Better for Coating the Surface of Iron E°(Fe+2/Fe) = -0.44v to P - Chemistry

Numerical

Using the E° values of A and B, predict which is better for coating the surface of iron [E°(Fe+2/Fe) = -0.44V] to prevent corrosion and why?

Given: E° (A+2/A)=-2.37 V: E°(B+2/B)= -0.14V

#### Solution

Given:

E°(A+2 / A) = 2.37 V

E°(B+2 / B) = -0.14 V

E_(cell)=E_(cell)^@ - (0.0591)/n log  [Cr^(3+)]^2/[Fe^(2+)]^3
(Nernst Equation)
0.261 = E_(cell)^@ = 0.0591/6 log  [0.001]^2/[0.001]^3

0.261 = E_(cell)^@ - (0.591 xx 2)/6

E_(cell)^@ = 0.2807V

Concept: Electrolytic Cells and Electrolysis - Introduction
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