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1. CV 12E/60/2005
FIRST ENGG. (CIVIL) EXAMINATION, 2005
(2nd Semester)
CHEMISTRY FOR CIVIL ENGG.
Time: Three hours Full Marks: 100
Answer any FIVE questions
1 i) Which one or more of the following species may remain
present in water?
a) H2O4 b) H7O3+ c) H5O2+
d) All of these
ii) For which of the following mixing ∆Hmixing ≠ 0 ?
a) 100cc of water is mixed with 100 cc of heavy water
b) 50cc of heavy water is mixed with 50cc of heavy
water
c) 100cc of water is mixed with 100 cc of water
d) None of the above
iii) Assuming that there is no other hardness contributing
substance present, the minimum hardness in a titre of
water will be brought in by
a) 20ppm of Mg SO4
b) 15mg/l of Mg (HCO3)2
[Turn over
2. [2]
c) 15ppm of Ca CO8
d) 20ppm of Ca SO4
[In answering the above questions, write the serial no.
of the correct answer and give reasons in brief] 20
2. a) What is a ligand? What kind of ligands are
NH3, H2O and EDTA?
b) Write the procedure for estimating total hardness of a
boiler feed water by EDTA method
c) Why alum is used in pre-treatment of municipal waters?
20
3. a) Why is TNT or nitroglycerine an explosive?
b) Why are Dynamite, Blasting gelatin and cordite impor-
tant in mega-construction projects in hill areas? State
their chemical compositions. 20
4. Explain why—
i) Glass articles are annealed
ii) Deltas are formed where the rivers meet the oceans
iii) Ferric carbonate is unknown
iv) Nitrogen does not generally form pentachalides
v) PH3 is well-known but not PH5 20
3. [3]
5. a) What is glass chemically?
b) Mention the distinction between mode of operation of
diesel engine and petrol engine.
c) What are the main constituents of LPG?
d) What are High Speed and Low Speed diesels? 20
5. What is Portland cement? What are the main constituents
of Portland cement; What do you mean by slag cement?
Describe the reactions (with equations) that are suggested to
taking place in the cement Klin. Discuss the setting and
hardening process of cement in detail (with equations). 20
6. What is refractory material? What are the basic require-
ments for a material to be refractory material? What do
you mean by spalling? ‘Glass maintains the energy, volume
and atomic arrangement of a liquid but for which the
changes in energy and volume with temperature are similar
in magnitude to crystalline solid’—Elabotate. 20
7. i) What is electrochemical corrosion? Explain the mecha-
nism of rust formation in
a) acid solution
b) neutral media. 7
[Turn over
4. [4]
ii) Explain—
a) If a drop of 3% solution of NaCl containing ferroxyl
indicator is placed on a piece of iron, the peripheral
regions of the drop become pink, whereas the area
under the drop becomes blue. A ring of rust
appears concentrically around the central region.
b) Pure iron does not dissolve readily in concentrated
HN03. 6
iii) What are the differences between them? 4
iv) ‘Small anodic area results in intense corrosion’-Explain
3
8. a) What are lubricants? Describe the mechanism of
Lubrication. 6
b) What are different Synthetic lubricants used?
c) Write notes on grease and solid lubricants. 6
d) ‘High resistance to oxidation is indicated by low sligh
number’—explain. 3
![[2]
c) 15ppm of Ca CO8
d) 20ppm of Ca SO4
[In answering the above questions, write the serial no.
of the correct answer and give reasons in brief] 20
2. a) What is a ligand? What kind of ligands are
NH3, H2O and EDTA?
b) Write the procedure for estimating total hardness of a
boiler feed water by EDTA method
c) Why alum is used in pre-treatment of municipal waters?
20
3. a) Why is TNT or nitroglycerine an explosive?
b) Why are Dynamite, Blasting gelatin and cordite impor-
tant in mega-construction projects in hill areas? State
their chemical compositions. 20
4. Explain why—
i) Glass articles are annealed
ii) Deltas are formed where the rivers meet the oceans
iii) Ferric carbonate is unknown
iv) Nitrogen does not generally form pentachalides
v) PH3 is well-known but not PH5 20](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)