Galvanized iron sheets are coated with

Options

A. `Cr`
B. `Zn`
C. `Ni`
D. `Cu`

Answer

B

Explanation

Galvanized iron is sheet iron coated with a layer of `Zn` to prevent corrosion, usually made by dipping the sheet `Al` added to prevent the formation of a brittle `Zn-Fe` alloy, Thus, galvanized iron is sometimes called Zinc-plated iron. Zinc is more easily oxidized than iron:
`Zn(s) rarr Zn^(2+)(aq.)+2e^(-) E^(@) = +0.76V`
So even if a scratch exposes the iron, the `Zn` is still attacked In this case, the `Zn` metal scrves as the anode and the iron is the cathode.