Roll No.
: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Amrita Vishwa Vidyapeetham
B.Tech. Degree Examinations – Nov/Dec. 2014
First Semester
CHY100 Chemistry
(Common to all branches)
Time: Three hours Maximum: 100 Marks
Answer all questions
Part A (15 × 2 = 30 marks)
1. After a period of time, your ion-exchange water softener no longer removes hard-water
ions. How can you "refresh" your water softener, using a material obtained from the
grocery store? Support with necessary equation.
2. How does wet steam formation affects the boiler safety?
3. Why NH3-NH4Cl buffer solution is added during the determination of hardness of water
by EDTA titration.
4. In ∆G vs. Temp graph carbon dioxide formation curve is almost parallel to X-axis and
carbon monoxide slops downwards. Reason out.
5. Calculate the maximum degree of freedom for a pure substance under equilibrium.
6. State condensed phase rule and explain the terms in it.
7. What happens to n→π* and π→π* transition of carbonyl compound when the polarity of
solvent is changed from non – polar to polar?
8. Predict the number of nmr signals for the compound, CH2 = CCl- CH2OH.
9. What is the importance of finger print region in IR spectroscopy?
10. Pin holes on tin coated iron are more prone to corrosion than pin holes on zinc coated iron.
Reason out.
11. An iron rod half immersed in water starts corroding just below the waterline? Give reason.
12. Explain why impure metals corrode faster than pure metals?
13. What are the advantages of OLED over LCD?
14. Differentiate between top down and bottom up techniques.
15. What are the conditions for a molecule to exhibit liquid crystalline behavior?
Part B (5 × 14 = 70 marks)
16. (a) Explain in detail with flow diagram, various steps involved in the treatment of water for
domestic supply. (6 marks)
(b) For regeneration of an exhausted zeolite bed it needed 150 litres of NaCl solution with
strength of 110 g/l. How many litres of hard water sample having 180 ppm hardness be
softened using this softener? (4 marks)
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(c) Explain the function of the following in water treatment: (1) calgon, (2) hydrazine,
(3) bleaching powder and (4) ozone. (4 marks)
17. (a) With a neat diagram explain the construction of phase diagram of Pb-Ag silver system.
Explain how phase rule is applied to the Pattinson’s process? (7 marks)
(b) Explain Ellingham diagram. Give any two practical applications of Ellingham
diagram. Reduction of chromium oxide is done by Al but not by C. Why? (7 marks)
18. (a) The force constant of nitric oxide is 1550N/m. Calculate the fundamental vibrational
frequency of NO in cm-1. Given the masses of N=14.006amu and O=15.994amu.
(4 marks)
(b) How do you differentiate inter molecular and intra molecular hydrogen bonding using
IR spectroscopy? Give an example. (4 marks)
(c) Why molecules absorb in UV- VIS region? What are the types of electronic
transitions that can occur in a molecule? Discuss giving examples. (6 marks)
19. (a) Give a detailed account on the different methods that can be adopted to reduce
corrosion of a metal. (6 marks)
(b) Differentiate the following: (1) galvanic series and electrochemical series (2) Pitting
corrosion and stress corrosion. (4 marks)
(c) Explain how corrosion can be controlled by the following methods:
(1) Design and selection of material
(2) Anodic protection (4 marks)
20. (a) What are liquid crystals? Distinguish between smectic, nematic and cholesteric types
with suitable examples. (5 marks)
(b) Discuss any two methods for the preparation of carbon nano tubes. (4 marks)
(c) What are conducting polymers? Explain the mechanism of p-doping by taking poly
aniline as the example. (5 marks)
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