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Code No: R5100104
I B.Tech (R05) Supplementary Examinations, June 2009 APPLIED CHEMISTRY (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) What is bleaching powder ? What is the mechanism of its action in sterilization of drinking water? (b) What are the disadvantages in its use? (c) Calculate the concentration of CaSO4 in solution in moles/litres if its hardness was found to be 50 ppm. [8+4+4] 2. (a) What are Zeolites ? (b) How is the softening of water carried out using Permutit Process?
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3. Explain what happens and why it happens (a) When a zinc article is under strain
[4]
(b) When iron sheets riveted with copper rivets
[4]
(c) when an iron pole is partly buried under soil
[4]
(d) When a metallic structure is buried under mineralized soils.
[4]
4. Explain what happens and why it happens
[4x4=16]
(a) When a zinc plate is attached below a ship. (b) When steel is alloyed with chromium homogeneously. (c) When there are crevices between the adjacent parts of the structure. (d) When there is no uniform flow of a corrosion liquid. 5. (a) What are silicone resins ? How are they made and what are their uses ? (b) Discuss the preparation, properties and uses of bakelite resins. 6. (a) Explain
[8] [8] [8]
i. the Segar Cones test ii. R.U.L. test. (b) Outline the important applications of refractories.
[8]
7. (a) Differentiate between cloud and pour points. (b) Classify lubricants giving examples for each class. 8. (a) Compare fat lime with hydraulic lime. (b) Give an account of the different classes of hydraulic limes. ?????
[8+8] [8] [8]
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Code No: R5100104
I B.Tech (R05) Supplementary Examinations, June 2009 APPLIED CHEMISTRY (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Calculate the total hard ness of a sample of water from Tirupati which showed the following analysis: CaCl2 = 11.1mg/litre; Mg(HCO3 )2 = 14.6 ppm; Mg(NO3 )2 = 14.8 ppm; Ca(HCO3 )2 = 8.1 ppm; (b) What is the concentration in moles/litre of CaSO4 if its hardness was found to be 20 ppm? [12+4] 2. (a) Explain the scale and sludge formation in boilers. (b) Calculate amount of lime (80%) and soda ( 90%) required to soften 12,000 litre of the water containing the following salts: CaCO3 = 185 ppm; CaSO4 = 34 ppm; MgCl2 = 76 ppm; organic matter = 84 ppm; SiO2 = 12ppm; Ca(HCO3 )2 = 220 ppm. [8+8] 3. (a) What are electrochemical series and galvanic series? (b) How do you differentiate the electrochemical series from galvanic series?
[5] [6]
(c) Explain why the rate of corrosion accelerate with reduction in the over voltage of the corroding metal? [5] 4. Explain how corrosion control can be brought by the following methods. (a) Proper designing
[5]
(b) Modifying the environment
[5]
(c) Use of inhibitors.
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5. (a) Describe the composition of natural rubber.
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(b) Explain the difference between natural and synthetic rubber.
[8]
(c) Write briefly on the compounding of rubber for engineering uses.
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6. (a) What are refractories ? Summarize their important characteristics. (b) Write a note on “askarels”.
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7. Write brief notes on the following:(a) Cloud and pour point. (b) Viscosity and viscosity index (c) Flash and fire points of lubricants.
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8. (a) What is meant by setting and hardening of cement? What are its advantages? [8] (b) Explain the initial and final setting of cement with relevant chemical reactions. [8] ?????
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Code No: R5100104
I B.Tech (R05) Supplementary Examinations, June 2009 APPLIED CHEMISTRY (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Describe the treatment processes used to obtain “Municipal Water”. (b) What is the concentration in moles/litre of CaCl2 if its hardness was found to be 20 ppm. [10+6] 2. (a) Write briefly on boiler troubles. (b) Calculate the quantities in Kgs of lime-soda needed to soften 30,000 litres of water having the following composition:- Determine the quantities (in Kgs) of lime and soda required for softening 10,000 liters of water having the following salts: NaCl = 5.85 mg/liter; KCl = 7.45 mg/litre; Ca(HCO3 )2 = 40.5 mg/litre; Mg(HCO3 )2 = 14.6 mg/litre; Mg(NO3 )2 = 14.8 mg/litre; CaCl2 = 12.1 mg/litre . [8+8] 3. Justify the following statements with suitable examples. (a) the rate of corrosion is dependant on the nature of the corroding environment. [8] (b) A pipe half buried in water undergoes corrosion fastly.
[8]
4. (a) What are cathodic coatings ? How do you differentiate cathodic coatings from anodic coatings? [8] (b) Explain the process of tinning with its advantages and disadvantages.
[8]
5. (a) Explain the difference between natural and synthetic high polymers with suitable examples. [8] (b) What is Polyethylene? How is it manufactured? Mention the different types of polyethylenes and their uses. [8] 6. (a) Explain the difference between thermal and electrical insulators.
[8]
(b) Write briefly on the applications of these two types of insulators.
[8]
7. How do you classify lubricants? Give their different modes of action.
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8. Give an account of the raw materials use din the manufacture of the lime and explain the manufacture of lime and explain the manufacture of fat lime. [16] ?????
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Code No: R5100104
I B.Tech (R05) Supplementary Examinations, June 2009 APPLIED CHEMISTRY (Civil Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) What are the important sources of water ? (b) What is the cause for alkalinity of natural water? (c) How do you estimate the hardness of water by EDTA?
[4+3+9]
2. (a) Describe the scale and sludge formation in boilers. (b) Discuss the ion-exchange process for softening of hard water. 3. (a) What is meant by stress corrosion? What are its characteristics? (b) Explain season cracking and caustic embrittlement. How is it prevented?
[8+8] [8] [8]
4. Differentiate the following with suitable examples. (a) Cathodic coatings with anodic coatings.
[8]
(b) Metal cladding and metal spraying.
[8]
5. (a) What is natural rubber ? How is crude rubber obtained from latex ? (b) Discuss the compounding and fabrication of plastics.
[8] [8]
6. (a) What are refractories ? How do you classify them ? Explain your answer with suitable examples. [8] (b) Write a note on thermal insulators.
[8]
7. (a) What are the criteria for the selection of lubricants? (b) Give the important applications of lubricants. 8. Explain the hardening and setting of cement using the chemical equations. ?????
[8+8] [16]