Applied Chemistry 2 - Dec 2015

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) What is 'Oxidation corrosion'? Why do gold and platinum metal not get corroded in atmospheric oxygen?(3 marks) 1 (b) Give composition, properties and uses of German silver.(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 'prevention of waste' principle in Green Chemistry.(3 marks) 1 (e) What are composite materials? Mention any four characteristics of composite materials.(3 marks) 1 (f) What is metal cladding? How is 'alclad' obtained.(3 marks) 1 (g) 1.5g of a coal sample was brunt in combustion apparatus and teh products of combustion were collected in previously weighed KOH bulb and CaCl₂ tube. The increase in weight of KOH bulb and CaCI₂ tube were found to be 3.92g and 1.25g respectively. Calculate percentage carbon and hydrogen in the sample.(3 marks) 2 (a) How do the following factors affect the rate of corrosion?
i) Relative areas of anodic and cathodic parts
ii) Purity of metal
iii) pH of medium.(6 marks) 2 (b) What is meant by 'Knocking' in internal combustion engine? Define Octane number. Name any two anti-knock agents.(5 marks) 2 (c) Calculate percentage atom economy for the following reaction with respect to cinnamaldehyde. $$ \overset{\text C_6 \text H_5 \text{CHO} } {\text{benzaldehyde }} + \overset {\text{CH}_{3}\text{CHO}} {\text{ acetaldehyde }} \overset{\overset{\text{NaOH}}{\longrightarrow} } { \text { }} \overset{\text{C}_6\text H_5 \text{CH} = \text{CHCHO}}{\text{ cinnamaldehyde }}+ \overset{\text H_2\text O}{ \text{water}} $$(4 marks) 3 (a) A gaseous fuel has the following composition by volume.
CO=46%     H₂=30%     CH₄=10%
C₂H₄ = 4%     N₂=1%     CO₂=2% and O₂=7%.
Calculate volume and weight of air required for complete combustion of 1m³ of fuel (Mol. wt. of air = 28.949).(6 marks) 3 (b) Explain conventional and greener route production of Indigo dye. Highlight the green chemistry principle involved.(5 marks) 3 (c) Explain Galvanic corrosion with the help of suitable example and diagram.(4 marks) 4 (a) What is power metallurgy? List various steps involved in power metallurgy. Mention the aim of each step.(6 marks) 4 (b) With the help of a diagram and electrode reactions, explain mechanism of electrochemical corrosion of iron by hydrogen evolution, in acidic medium.(5 marks) 4 (c) Explain 'sandwich panel' type layered structural composites, with a suitable diagram. Mention their application.(4 marks) 5 (a) With a suitable diagram, explain process of refining to petroleum. Name any two fractions obtained.(6 marks) 5 (b) How are plain carbon steels classified based on carbon content? What are the drawbacks of plain carbon steels?(5 marks) 5 (c) Discuss influence of any two chemical factors on adhesive action.(4 marks) 6 (a) Define 'Paint'. Mention any four constituents of plaint their functions.(5 marks) 6 (b) A sample of coal has the following composition by mass:
C=70%.     H=10%,     O=4%   ;
S=2%,     N=2% and Ash=12%
Calculate Gross and Net calorific value using Dulong's formula.(5 marks) 6 (c) Distinguish between Brass and Bronze.(5 marks)