Applied Chemistry 2 - May 2013

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 from the following:-

1 (a) Why silver, gold and platinum do not undergo oxidation corrosion? (3 marks) 1 (b) Define Octane number and Cetane number. Give their significance.(3 marks) 1 (c) Give the composition, properties and uses of German Silver.(3 marks) 1 (d) Give classification of composite material. (3 marks) 1 (e) What is green chemistry? List the 12 principles of green chemistry.(3 marks) 1 (f) State the characteristics of good paint. (3 marks) 1 (g) A coal sample was subjected to ultimate analysis. 0.6gm of coal on combustion in a bomb calorimeter, produces 0.05gm of BaSO₄. Calculate the percentage of S in the coal sample. (3 marks) 2 (a) What are metallic coatings? Distinguish between galvanizing and tinning.(6 marks) 2 (b) Explain refining of petroleum with suitable diagram. (5 marks) 2 (c) Calculate percent atom economy for following reactions: (w.r.t chlorobenzene).
(4 marks) 3 (a) A coal sample has the following composition by weights: C = 82%, H = 3%, O = 8%, S = 2%, N = 2% and Ash = 3%. Calculate the minimum amount of air required both by weight and volume for complete combustion of 2 Kg of coal. (molecular wt. of air = 28.949 gm)(6 marks) 3 (b) Explain traditional and greener route of production of indigo dye. By this reactions which principle of green chemistry is shown?(5 marks) 3 (c) How is the rate of corrosion influenced by :-
i) pH of the medium
ii) Relative area of cathode and anode part?(4 marks) 4 (a) Write a note on compacting and sintering. (6 marks) 4 (b) Explain wet corrosion in acidic medium with schematic diagram and mechanism. (5 marks) 4 (c) Explain laminar composite with suitable example. (4 marks) 5 (a) What is biodiesel? Explain the method to obtain biodiesel from vegetable oil. Give advantages of biodiesel as fuel.(6 marks) 5 (b) Distinguish between brass and bronze. (5 marks) 5 (c) State the chemical factors influencing adhesive action.(4 marks) 6 (a) What is cathodic protection? Describe impressed current method of corrosion control. (5 marks) 6 (b) A gaseous fuel has the following composition by volume: H₂ = 10%, CH₄ = 30%, C₃H₈ = 20%, CO = 20%, CO₂= 15%, N₂ = 5%. Calculate the volume of air required for complete combustion of 1 m³ of fuel.(5 marks) 6 (c) Explain the effect of following elements on alloying:-
(i) Nickel
(ii) Chromium
(iii)Cobalt
(iv)Molybdenum
(v)Tungsten(6 marks)