Engineering Chemistry - Dec 2012
First Year Engineering (Set B) (Semester 2)
TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks.
Solve any one question from Q1 & Q2
1 (a) Give the chemical reactions involved in lime-soda process of softening of water.(6 marks)
1 (b) Why is water soften before using in boiler?(2 marks)
1 (c) The hardness of 10000 litres of a sample of water was removed by passing it through a zeolite softener. The zeolite softner then required 200 litre of sodiumchloride solution containing 150 gm/litre of NaCI for regeneration. Find out the hardness of Water sample.(6 marks)
10 (a) Write short notes on any two of the following:
(iii) Lambert's and Beer's Law(7 marks) 10 (b) 100 ml of a water sample required 20 ml of N/50 H2SO4 for neutralization to phenolphthalein end point. After this methyl orange indicator was added to this and further acid required was 15 ml calculate the type and extent of alkalinity.(7 marks) 2 (a) Why hardness of water estimated equivalent of CaCO3?(4 marks) 2 (b) How exhausted resins are regenerated in ion-exchange method of water softening.(3 marks) 2 (c) Is bleaching powder behaves as disinfectant, explain.(4 marks) 2 (d) A water sample containing 136 mg of CaSO4 per litre calculate the hardness in terms of CaCO3 equivalents.(3 marks)
Solve any one question from Q3 & Q4
3 (a) Define gross and net calorific value of fuel.(2 marks)
3 (b) Discuss in brief the proximate analysis of coal and give its significance.(3 marks)
3 (c) The percentage composition by weight of a sample of coal was found to be as uder-
C=81%, H=5%, S=1%, N=1% and ash 3.5%.
Calculate the minimum amount of oxygen and air required for complete combustion of 1 kg coal.(9 marks) 4 (a) Explain octane and cetane number of gasoline.(3 marks) 4 (b) Define chemical fuel. How they are classified, give suitable example of each type.(3 marks) 4 (c) A coal sample has the following percentage composition C=82%, H=3.1%, S=1.1%, N=0.8%, O=3.9%, Ash=9.1%.
Calculate approximately gross calorific (GCV) and net calorific. Value (NCV) in cal/gm.(8 marks)
Solve any one question from Q5 & Q6
5 (a) What do you mean by viscosity index?(5 marks)
5 (b) What are refractories, give their classification?(5 marks)
5 (c) Write a short note on portland cement.(4 marks)
6 (a) Define flash point and fire point.(2 marks)
6 (b) What are the raw material of refractory?(4 marks)
6 (c) An oil of unknown viscosity index has saybolt universal viscosity of 58 seconds at 210°F and 580 seconds at 100°F.
The high viscosity index standard oil has saybolt viscosity of 58 seconds at 210°F and 430 seconds at 100°F. The low viscosity index standard has saybolt universal viscosity of 58 seconds at 210°F and 780 seconds at 100°F. Determine V.I. of unknown oil.(8 marks)
Solve any one question from Q7 & Q8
7 (a) Give the mechanism of addition polymerization.(7 marks) 7 (b) Give preparation, properties and uses of Nylon 6:6, teflon.(7 marks) 8 (a) What is polymerization? Explain condensation polymerization with the help of two examples.(3 marks) 8 (b) Give preparation properties and uses of PVC and silicone resin.(11 marks)
Solve any one question from Q9 & Q10
9 (a) Write short note on UV spectroscopy.(2 marks)
9 (b) (i) Give reason:
Alkalinity due to OH- and HCO3- ions can not be present simultaneously in water.(6 marks) 9 (b) (ii) If Na2SO4 dissolve in water. It will create the alkalinity in water.
solution was made to one litre by dilution. 50 ml of this solution required 40 ml of EDTA solution, while 50 ml of the sample of water required 20 ml of EDTA. Calculate total hardness of water sample.(6 marks)