Anna University Applied Chemistry II Test Paper for Marine Engineering
II Semester – Marine Engineering
APPLIED CHEMISTRY — II
Time : Three hours Maximum : 100 marks
Answer ALL questions.
PART A — (10 ´ 2 = 20 marks)
1. Define gross calorific value. Show a mathematical relation between gross and net calorific values.
2. Give the composition of LPG. Mention its merits as domestic fuel.
3. Define spontaneous ignition temperature.
4. Calculate the minimum amount of air required for complete combustion of 1 kg of carbon. Given that oxygen in air is 23% by weight.
5. What is a reversible cell? Give one example with cell reaction.
6. What is electro–motive series? What is its significance?
7. How is vitreous coating applied to metals? What are its advantages?
8. Give the composition of a lacquer.
9. What are the characteristics of an explosive?
10. Mention the number of phases, number of components and degrees of freedom for the following equilibrium.
PART B — (5 ´ 16 = 80 marks)
11. (i) Detail out the refining process of crude oil with a neat sketch. Mention the temperature, fractions collected and their uses. (10)
(ii) Discuss the manufacture of producer gas with a neat sketch. Also mention the reactions that take place at various zones. (6)
12. (a) Detail out the experimental method to analyse the flue gas by Orsat’s apparatus with diagram. (16)
(b) A sample of coal was found to contain the following constituents by weight. C 81%; Sulphur 1%; Hydrogen 5%; Ash 5%, rest oxygen. Calculate the amount of air supplied for the complete combustion of 3 kg of coal if 40% excess air is supplied. (16)
13. (a) (i) State Kohlrausch’s law. Mention its applications. (6)
(ii) How is EMF of a cell determined experimentally? (10)
(b) (i) Explain the mechanisms of galvanic cell corrosion and differential aeration corrosion with suitable illustrations. (8)
(ii) Discuss the ways and means to prevent (or) control corrosion. (8)
14. (a) (i) Discuss the methods that are employed for cleaning the surfaces of metals prior to coating. (6)
(ii) Explain the coating processes : Hot dipping and electroplating. (10)
(b) (i) What are the requirements of a good paint? (6)
(ii) What are the constituents of a paint formulation? Mention their functions and example for each. (10)
15. (a) Draw the phase diagram of ice–water water vapour system and discuss the various phases and degrees of freedom. (16)
(b) (i) Draw and explain the phase diagram of lead–silver system. Explain the principle involved in the Pattinson’s process of desilverisation of lead. (12)
(ii) Write short notes on ‘smoke bomb’. (4)