Question

Zine can be coated on iron to produce galvanize3d iron but the reverse is not possible it is because
A. zinc is lighter than iron
B. zinc has lower melting point than iron
C. zinc has lower negative electrode potential than iron
D. zinc has higher negative electrode potential than iron.

Answer 1

Correct Answer - D
(d) The metal with higher negative standard reduction potential, have higher tendency to get reduced.
`Zn^(2+)+2e^(-) to Zn,E^(@)=-0.76V`
`Fe^(2+)+2e^(-) to Fe, E^(@)=-0.44V`
Here, in galvanised iron, Zn has higher negative reduction potential means Zn takes electrons given by iron and itself gets reduced.
Thus, Zn works as anode and protects iron from rusting by making iron as cathode.