Applied Chemistry 1 - Dec 2015

First Year Engineering (Semester 1)

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.

Attempt any five from the following:

1 (a) Why is Hot lime-soda process preferred over cold lime-soda method?(3 marks) 1 (b) What are the drawbacks of natural rubber.(3 marks) 1 (c) List the applications of carbon nanotubes.(3 marks) 1 (d) Define flash point and fire point. Give its significance.(3 marks) 1 (e) What is Triple point? Explain it with reference to one component water system.(3 marks) 1 (f) Distinguish between thermoplastic and the thermosetting resins.(3 marks) 1 (g) A 5ml sample of waste water was refluxed with 30ml of potassium dichromate solution and after refluxing the excess unreacted dichromate required 23ml of 0.1M FAS solution. A blank of distilled water on refluxing with 30ml of dichromate solution required 36ml of 0.1M FAS solution. Calculate the COD value of the waste water.(3 marks) 2 (a) Calculate the quantity of pure lime (70% pure) and soda (85%pure) required for softening of 100,000 litres of water containing the following impurities in ppm.
Ca(HCO₃)₂=30.2, Mg(HCO₃)₂=20.8, CaCl₂=28.1, MgCl₂=8.78, CaSO₄=35, MgSO₄=6.7, NaCl=17.9.(6 marks) 2 (b) What is the phase Rule? Draw a neat labelled diagram for water system. Using phase rule find the number of degrees of freedom (F) for the following systems;
i) lce_(s) ⇔ water_(l) ⇔ water vapour_(g)
ii) Water ⇔ water vapour(5 marks) 2 (c) Explain the preparation, properties and uses of silica bricks.(4 marks) 3 (a) Define: Lubricants, Lubrication. Discuss the boundary-film Lubrication mechanism.(6 marks) 3 (b) What is meant by fabrication of plastic? Explain in details the injection moulding method.(5 marks) 3 (c) Discuss the limitations of phase rule.(4 marks) 4 (a) Write the preparation, properties and uses of any two of the following:
i) Kevlar
ii) PMMA
iii) Buna-S(6 marks) 4 (b) What is activated sludge? Explain the method with a flow-sheet diagram.(5 marks) 4 (c) Find the acid-value of vegetable oil whose 5ml required 2ml of N/10 KOH during titration (Density of oil = 0.92).(4 marks)

Write notes on (Any two):

5 (a) (i) Decay of concrete(3 marks) 5 (a) (ii) Setting and hardening of cement(3 marks) 5 (b) Explain the function of the following constituents in the compounding of plastics. Give proper example (Any Two):
i) Filters
ii) Plasticizers
iii) Lubricants(5 marks) 5 (b) RCC(3 marks) 5 (c) The hardness of 75,000 litres of a water sample was completely removed by a permutit. The exhausted permutit then required 1500L of NaCl containing 117mg of NaCl per litre for regeneration. Calculate the hardness of water sample.(4 marks) 6 (a) Explain with a neat diagram, the zeolite process of water softening including the following points.
i) Principle
ii) Softening and regeneration reactions
iii) Process
iv) Advantages(6 marks) 6 (b) What is vulcanization? Explain giving proper reaction. Discuss the improvement in the drawbacks of natural rubber after vulcanization.(5 marks) 6 (c) Under what conditions are solid lubricants used? Explain Graphite as a solid lubricant.(4 marks)