A1102 diss, a ப. 805: ஆ
a ١ ഫു
b) What is Buna-S.? Mention the Historical importance? പ്രാന്‌ ~~ )
a) A sample of coal contains 60% C, 33% 0, 6% ೫, 0.5% 5, 0.2% Ni क ‏موقي‎ (த)
Ash. Calculate the GCV and NCV of coal.
b) What are greases? Under what conditions they are preferred over a liquid (6)
lubricant.
OR
a) What is Natural gas? Distinguish between LNG and CNG. What is the (5)
technical difficulty to use LNG fuel in a car?
b) Calculate the HCV and LCV of ethanol using Dulong’s formula. (5)
a) 100 mL sewage water is diluted to 1000 mL with dilution water; the initial (5)
dissolved oxygen was 7.6 ppm, dissolved oxygen level after five days 08 `

incubation was 3.2 ppm. Find the BOD of the sewage water.

b) Compare aerobic and anaerobic oxidation of sewage water. (5)
OR

a) Discuss the steps involved in sewage water treatment. (5)

b) Explain the working of trickling filter process with a neat labelled sketch. (5)
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