Engineering Chemistry - Dec 2013

First Year Engineering (Semester 2)

TOTAL MARKS: 50
TOTAL TIME: 2 HOURS (1) Solve Q.1 or Q.2, Q.3 or Q.4, Q.5 or Q.6, Q.7 or Q.8
(2) Assume suitable data, if necessary.

Answer any one question from Q1 & Q2

1 (a) Explain formation of scales in boiler, give their disadvantages and methods of removal.(6 marks) 1 (b) Calculate potential on redox electrode dipped in titration mixture, when 20 ml of 0.1 N Ce⁴⁺ solution from the burette is added in 100 ml 0.1 N Fe²⁺ solution. Standard reduction potentials for Fe³⁺- ? Fe²⁺ and Ce⁴⁺ - ? Ce³⁺ are 0.75 and 1.45 V respectively.(3 marks) 1 (c) Explain the conductometric titration of KCI against AgNO₃ solution from burette.(3 marks) 2 (a) Explain the principle, instrumentation and applications of UV-Visible spectrophotometer.(6 marks) 2 (b) State the problems in traditional synthesis route and advantages of green route in manufacture of adipic acid.(3 marks) 2 (c) A zeolite softner gets exhausted on softening 4000 litres of hard water. Calculate hardness of the water if the exhausted zeolite requires 10 litres of 10% NaCl solution for regeneration.(3 marks)

Answer any one question from Q3 & Q4

3 (a) (i) Give structural change on vulcanization of natural rubber molecules with sulphur. How does it affect the strength?(3 marks) 3 (a) (ii) State the purpose of compounding polymers with plasticizers and fillers.(3 marks) 3 (b) (i) Give the reaction involved in biodiesel formation and state any three advantages of biodiesel.(3 marks) 3 (b) (ii) Calculate the amount of air (20% excess) required for complete combustion of 1kg wood if it contains 55% carbon, 8% hydrogen, 5% oxygen and remaining non combustible part.(3 marks) 4 (a) (i) Define biodegradation of polymers. State favourable structure of polymer for biodegradation. Write structure of biopol(PHBV).(3 marks) 4 (a) (ii) Give any six differences in thermosoftening and thermosetting polymers.(3 marks) 4 (b) Give construction, working and calculation for finding gross calorific value of a solid fuel by Bomb calorimeter.(6 marks)

Answer any one question from Q5 & Q6

5 (a) Give industrial methods of manufacturing of hydrogen gas.(5 marks) 5 (b) Explain structure of diamond, give its properties and applications.(5 marks) 5 (c) Give preparation, reactions of saline hydrides.(3 marks) 6 (a) State the difficulties in storage of hydrogen gas. Give its chemical storage in alanates and metal hydrides.(5 marks) 6 (b) Give preparation, reactions of silane.(4 marks) 6 (c) Give any one method of preparing carbon nanotubes. State applications of carbon nanotubes.(4 marks)

Answer any one question from Q7 & Q8

7 (a) Give the mechanism of electrochemical corrosion.(5 marks) 7 (b) Explain 'nature of metal' factors affecting rate of corrosion.(5 marks) 7 (c) What are types of metallic coatings? Which is prefered? Why?(3 marks) 8 (a) Give principle, construction and applications of cathodic protection.(5 marks) 8 (b) Explain 'powder coating' method for corrosion control.(4 marks) 8 (c) Account on, 'nature of oxide films on metal surface and its effect on further corrosion.(4 marks)