Answer the following question.
a) What is meant by corrosion?
b) Write names of any two methods of prevention of corrosion.
c) In which method, metal like copper, aluminium are coated with a thin layer of their oxides by means of electrolysis.
d) Explain this method with diagram.
a. corrosion: Corrosion is a process where the water or the moisture on the surface of the metal oxidizes with the atmospheric oxygen.
b. Methods of prevention (any two each carry 1/2 mark) 1
1. Galvanizing 2. Anodization 3. Tinning
4. Electroplating 5. Alloying
d. In this process cupper, aluminum are coated with a thin layer of their oxides by means of electrolysis. For this copper or aluminum article is used as anode. It obstructs the contact of the aluminum or copper with oxygen and water.