We know that zinc,copper can be used to coat Iron. However Iron is not used to coat zinc. Why is it so?
The reason why zinc and copper can be used to coat iron, but iron is not commonly used to coat zinc, is due to the difference in their reactivity or electrochemical behavior. This concept is based on the activity or reactivity series of metals.
The reactivity series is a list of metals arranged in order of their reactivity, with the most reactive metal at the top. The reactivity of a metal determines its ability to displace another metal from a compound or solution. In general, a metal higher in the reactivity series can displace the metal lower in the series from its compound.
Zinc is higher in the reactivity series compared to iron, which means it is more reactive. As a result, zinc can displace iron from its oxide or chloride compounds when they come into contact with each other. This property makes zinc an effective coating for iron, as it can provide a protective layer that prevents the underlying iron from corroding.
On the other hand, iron is lower in the reactivity series compared to zinc. This means that iron is not reactive enough to displace zinc from its compounds. Therefore, iron cannot effectively form a protective coating on zinc surfaces.
In summary, the difference in reactivity between zinc and iron is the reason why zinc and copper can be used to coat iron, but iron is not commonly used to coat zinc. Zinc is more reactive and can displace iron from its compounds, providing a protective coating. Iron, however, is not reactive enough to displace zinc from its compounds, making it unsuitable for coating zinc surfaces.