Question

Define corrosion. Under what conditions does corrosion takes place and how can it prevent ?

Answer 1

Process of slowly eating away of metal due to attack of atmospheric gas on the surface of metal resulting into formation of compounds such as oxides , sulphides , carbonates., sulphates etc. is called corrosion

Example — Rusting of iron

Formula — Fe2O3.xH2O

Prevention of corrosion

• By applying film of oil and grease on the surface of iron tools and machinery .
• The metal surface is coated with paint which keeps it out of contact with air , moisture etc. till the paint layer develops cracks

Factors which promotes Corrosion

• Reactivity of impurities
• presence of electrolytes
• Strains in metals — corrosion take place rapidly at bends , nicks ,cuts in metal
• Presence of air and moisture