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
E°(A+2 / A) = 2.37 V
E°(B+2 / B) = -0.14 V
In 1st case :
`E_`= E° (A2+ / A) - E° (Fe2+ /Fe)
= (-2.37 + 0.44) = -1.93 V
In 2nd case :
`E_`= E°(B2+/B) - E° (Fe2+/Fe)
=(-0.14 + 0.44) = 0.3 V
As B has a positive value, it will be our choice for electroplating.
Video Tutorials For All Subjects
- Electrolytic Cells and Electrolysis - Introduction