Question

write short note on corrosion of metals?

Answer 1

Corrosion of metals is a chemical change. When a metallic surface comes in contact with Oxygen, the metal reacts with Oxygen to form metal oxide. That changes the color of the surface. Also the properties of the surface change. The surface loses the lustre and shine. It becomes rough and soft.

For example:  4  Al + 3 O2 =>  2 Al2 O3
                          2 Fe + O2   =>   2 Fe O

Corrosion also happens when damp air or water gets in contact with metallic surfaces. The reason is the same.

The problem is that we all use metals at home and in industries. Due to the corrosion, the objects lose good appearance and also prevent their good use. That weakens the object too. Also more friction results due to corrosion. So corrosion is bad for humans. To prevent corrosion, alloys of metals are made and special heat treatment is also done. Some oils, paints or chemicals are polished or applied on metallic surfaces.

If we eat food that is stored in a rusted container, it is dangerous to our health. So corrosion is not good for us.

Answer 2

corrosion is a natural process. which converts a refined metal to more chemically stable from, such as its oxides ,hydroxides, or sulfide. it is the gradual destruction of materials by chemical and electrochemical reaction with their environment . corrosion engineering is the field dedicated to controlling and stopping corrosion.