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Code No: R5100304
I B.Tech (R05) Supplementary Examinations, June 2009 ENGINEERING CHEMISTRY (Mechanical Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) What is meant by carbonate and non-carbonate hardness of water? (b) Explain why hard water does not produce leather with soap? (c) A sample of hard water contains the following dissolved solids per litre. Ca(HCO3 )2 =16.4 mgs, Mg(HCO3 )2 = 14.6 mgs, CaCl2 = 111 mgs, MgSO4 = 12 mgs, CO2 = 44 mgs and CaSO4 =13.6 mgs. Calculate temporary and permanent hardness of water in ppm and in degree clank. [6+4+6] 2. (a) With the help of a neat diagram, explain the reverse osmosis method for desalinationof brackish water. (b) Write a brief account on boiler corrosion.
[8+8]
3. What happens and why it happens for the following: (a) When a zinc plate fixed below the ship. (b) When an iron pole is partly buried under earth. 4. Write note on:
[8+8] [16]
(a) Solvent cleaning (b) Pickling and Etching (c) Sand blasting. 5. (a) Distinguish between addition and condensation polymerization. (b) Explain the differences between Thermoplastics and Thermosetting Plastics. (c) What is meant by Degree of Polymerization?
[6+6+4]
6. Explain the following two theories for the mechanism of the lubricants. (a) Boundary lubrication (b) Extreme pressure lubrication.
[8+8]
7. (a) Explain calcium-base, soda-base and lithium based greases. (b) Write a notes on solid lubricants.
[8+8]
8. (a) Define a Fuel? How chemical fuels are classified and give examples for each. (b) What is meant by Calorific value of a fuel? Define calorie and kilocalorie. [10+6] ?????
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Code No: R5100304
I B.Tech (R05) Supplementary Examinations, June 2009 ENGINEERING CHEMISTRY (Mechanical Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) What is hardness of water? What are its units? How do you express the hardness of water? (b) Explain any one method for the estimation of hardness of water.
[8+8]
2. (a) With the help of a neat diagram, explain the reverse osmosis method for desalinationof brackish water. (b) Write a brief account on boiler corrosion.
[8+8]
3. (a) What is corrosion? What are the units in which it is expressed? How is it different from errosion? (b) Explain the mechanism of electrochemical corrosion. 4. Discuss the following:
[8+8] [16]
(a) Galvanization (b) Cementation (c) Chromizing. 5. (a) What is PVC? How is it prepared? Write the engineering application of PVC. (b) Write preparation, properties and uses of phenol formaldehyde resins.
[8+8]
6. Write a note on lubricants with special reference to their classification, mode of action, examples and applications. [16] 7. (a) Explain the hydrodynamic lubrication (b) Write notes on semi-solid lubricants.
[8+8]
8. (a) Define a Fuel? How chemical fuels are classified and give examples for each. (b) What is meant by Calorific value of a fuel? Define calorie and kilocalorie. [10+6] ?????
3
Code No: R5100304
I B.Tech (R05) Supplementary Examinations, June 2009 ENGINEERING CHEMISTRY (Mechanical Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) What is hardness of water? How do you express the hardness? What are the units to express the hardness? (b) Give an account of the disadvantages of hard water.
[8+8]
2. Explain the Ion-exchange method for the removal of dissolved impurities and its advantages over lime soda process. [16] 3. Write short notes on: (a) Over voltage (b) Cathodic-protection.
[8+8]
4. (a) How will you differentiate a paint from varnishes and lacquers? (b) What is anodizing?
[10+6]
5. (a) Write a note on properties and uses of Teflon. (b) Differentiate the Natural Polymer and synthetic polymer. (c) Write a note on silicone rubbers.
[4+6+6]
6. Write a note on lubricants with special reference to their classification, mode of action, examples and applications. [16] 7. Describe the various types of lubrication.
[16]
8. (a) Explain the proximate analysis of coal and its significance. (b) Distinguish between low temperature carbonization and high temperature carbonization. [8+8] ?????
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Code No: R5100304
I B.Tech (R05) Supplementary Examinations, June 2009 ENGINEERING CHEMISTRY (Mechanical Engineering) Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Explain the different sources of water and their composition. (b) With the help of the relevant chemical equations give an account of the effect of water on rocks and minerals. [8+8] 2. (a) With the help of a neat diagram, explain the reverse osmosis method for desalinationof brackish water. (b) Write a brief account on boiler corrosion.
[8+8]
3. Write a short account on the following: (a) Pitting corrosion (b) Stress corrosion.
[8+8]
4. Explain the following terms:
[16]
(a) Drying oil (b) Thinners (c) Driers (d) Fillers. 5. (a) What is a homochain polymer? Give examples. (b) What is polymerization? Explain the different types of polymerization with examples. [4+12] 6. Explain the following two theories for the mechanism of the lubricants. (a) Boundary lubrication (b) Extreme pressure lubrication.
[8+8]
7. (a) What are the functions of lubricants? (b) Write a note on extreme pressure lubrication.
[8+8]
8. (a) Define a Fuel? How chemical fuels are classified and give examples for each. (b) What is meant by Calorific value of a fuel? Define calorie and kilocalorie. [10+6] ?????