Question

Using the E° values of A and B, predict which is better for coating the surface of iron [ E° (Fe2 +/ Fe) = -0.44 V ] to prevent corrosion and why ?
Given E° (A2 + / A) = -2.37 V and E° (B2+ / B ) = -0.14 V

Answer 1

Answer : The $E^o(A^{2+}/A)=-2.37V$ is better for coating the surface of iron to prevent corrosion.

Explanation :

As we are given the value of standard cell potential of iron is, $E^o(Fe^{2+}/Fe)=-0.44V$. This is the reduction potential of iron.

The reduction potential of A and B are, $E^o(A^{2+}/A)=-2.37V$ and $E^o(B^{2+}/B)=-0.14V$ respectively.

For the prevention of iron from the corrosion, we are using the substance A for the coating of the surface of iron.

As the reduction potential will be more, the more number of electrons will be lose by the substance and it will prevent from the corrosion. So, the reduction potential of A is more than the reduction potential of B.

Hence, the $E^o(A^{2+}/A)=-2.37V$ is better for coating the surface of iron to prevent corrosion.