Question

give a reason :
a) zinc is used in galvanising iron and not copper.

Answer 1

Zinc is more reactive than iron, it isused to protect it from corrosion because when oxygen in the air reacts with the surface of zinc, a very dense and impermeable coating of zinc oxide is formed and it is this physical barrier that protects the zinc surface from further attack.

Answer 2

What are the two conditions for rusting to occur are presence of oxygen and water (or water vapour). Oiling also prevents the contact of iron with moisture and air. Other methods for preventing rusting are Galvanizing, Chrome-plating, alloying, painting

Example for galvanised iron using in our daily life are in GI water pipes, GI sheets