Tutorial-5

TUTE –SHEET-5
CORROSION

1. Define corrosion . What are different types of corrosion? Explain the electrochemical theory of wet corrosion, giving its mechanism.
2. (a) Explain rusting of Iron with the help of electrochemical theory of corrosion.
(b) Differentiate between chemical corrosion and electrochemical corrosion.
(c) What will happen when stainless is immersed in aerated and de aerated sodium chloride solution?
3. (a) Write chemical reaction taking place during stress corrosion of brass.
(b) Illustrate the reactions involved in differential aeration corrosion with difference to the iron materials.
4. Explain the mechanism of following types of corrosions.
a) Chemical corrosion
b) Stress corrosion
c) Water-line corrosion
d) Pitting corrosion
e) Bimetallic or galvanic corrosion
5. (a) Mention different methods used for prevention of corrosion of metals and discuss any one of them.
(b) Write short notes on cathodic protection.
6. (a) Why impure metal are more susceptible to corrosion than pure metals?
(b) What are the factors, which affect corrosion?
7. What are metallic coatings? Explain the functioning of two types of metallic coatings. Explain the methods employed for coating metals.

8. Write short notes on the following:
(i) Electroplating, (ii) Metal Cladding.
9. What are electrochemical and galvanic series? Distinguish between the two and point out their role in corrosion.
10. What is sacrificial protection from corrosion? Give examples and explain any one in detail.
11. What are corrosion inhibitors ? Give some examples of organic and inorganic inhibitors. Enlist two applications where voltage inhibitors are used.