Applied Chemistry 2 - Dec 2014

First Year Engineering (Semester 2)

TOTAL MARKS: 60
TOTAL TIME: 2 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Use suitable data wherever required.
(4) Figures to the right indicate full marks.

Answer any five of the following:-

1 (a) Distinguish between Galvanizing and tinning.(3 marks) 1 (b) Give composition, properties and uses of Duralumin.(3 marks) 1 (c) What is 'cracking' of heavy oil? Mention any four advantages of catalytic cracking over thermal cracking.(3 marks) 1 (d) Explain 'Design for Energy Efficiency' principle in Green Chemistry.(3 marks) 1 (e) What are composite materials? Mention any four characteristics properties of composite materials.(3 marks) 1 (f) Gold and platinum do not get corroded in atmospheric oxygen. Explain.(3 marks) 1 (g) A sample of coal has the following composition by mass: C=75%, H=7%, O=8%, S=4%, N=2% and Ash=4%. Calculate Gross Calorific value of the fuel using Dulong's formula.(3 marks) 2 (a) What is Electrochemical corrosion? With a suitable diagram ans electrode reactions, explain electrochemical mechanism of rusting of iron in neutral, aqueous medium.(6 marks) 2 (b) What is meant by 'knocking' in internal combustion engine? Define Octane number and Octane number. Name any two anti-knock agents.(5 marks) 2 (c) Calculate percentage atom economy for the following reaction with respect to alkyl chloride.
CH₃-CH=CH₂+Cl₂ → Cl-CH₂-CH=CH₂(alkyl chloride) +HCl(4 marks) 3 (a) A gaseous fuel has the following composition by volume:
H₂=40%, CH₄=30%, CO=10%, C₃H₈=12%, N₂=3%, O₂=2% and CO₂=3%. Calculate volume and weight of air required for complete combustion of 1 m³ of fuel. (Mol. wt. of air =28.949)(6 marks) 3 (b) Explain conventional and green chemistry route of production of Indigo dye. Highlight the green chemistry principle involved.(5 marks) 3 (c) How do the following factors affect the rate of corrosion?
(i) Relative areas of anodic and cathodic parts.
(ii) Position of metal in galvanic series.(4 marks) 4 (a) What arc alloy steels? Explain special effects of the following metals on properties of alloy steels.
(i) Chromium
(ii) Nickel
(iii) Cobalt
(iv) Tungsten(6 marks) 4 (b) Explain differential aeration corrosion with the help of a suitable example.(5 marks) 4 (c) Explain laminar composites with suitable example.(4 marks) 5 (a) What is bio-diesel? Explain method to obtain bio-diesel from vegetable oil. What are the advantages of bio-diesel ?(6 marks) 5 (b) What is Powder metallurgy? Explain Powder Injection moulding method of compaction.(5 marks) 5 (c) Define matrix phase of composite materials. State functions of matrix phase.(4 marks) 6 (a) What is the principle of cathodic protection method of corrosion control? Explain Sacrificial anodic protection method.(5 marks) 6 (b) 2.5 g. of a coal sample was analysed for nitrogen content by Kjeldahl's method. The liberated ammonia required 12.7 ml of 0.5 NH₂SO₄ solution for neutralization. In a separate experiment, using Bomb calorimeter, 1.5 g of coal sample gave 0.28g of BaSO₄. Calculate percentage Nitrogen and Sulphur in the sample.(5 marks) 6 (c) How are plain carbon steels classified based on carbon content? What are the drawbacks of plain carbon steels?(5 marks)