Applied Chemistry

Set No.1

Code No: RR10104 I B.Tech.

Time: 3 hours

Regular Examinations, June -2005 APPLIED CHEMISTRY (Civil Engineering) Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ?????

1. Give an account of the various factors influencing corrosion by giving suitable examples. 2. Write brief account on (a) Metal spraying. (b) Corrosion inhibitors 3. What is meant by chemical conversion coating? Explain the phosphate coating, chromate coatings and chemical oxide coatings. 4. (a) How are polymers classified based on i. tacticity and ii. nature of monomer. (b) Discuss the manufacture and uses of i. Buna-S rubber ii. Buna-N rubber 5. (a) Describe a method for estimating temporary hardness of water using Hehner’s procedure. (b) Outline the EDTA method for determining the permanent hardness of water. 6. (a) Calculate the total hardness of a sample of water from Tirupati which showed the following analysis:- CaCl2 = 11.1 mg/litre; Mg(HCO3 )2 = 7.3 mg/litre; Mg(NO33 )2 = 14.8 mg/litre; Ca(HCO3 )2 = 8.1 mg/litre. (b) What is the concentration in moles/litre of CaSO4 if its hardness was found to be 20 ppm ? 7. (a) Write a general method for manufacture of refractories. (b) Summarize their important characteristics. 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. ?????

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Set No.2

Code No: RR10104 I B.Tech.

Time: 3 hours

Regular Examinations, June -2005 APPLIED CHEMISTRY (Civil Engineering) Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ?????

1. (a) What is corrosion? How is it different from erosion? Explain the term passivity with suitable examples. (b) Give an account of the oxidation corrosion with relevant chemical equations involved. 2. Write short notes on (a) Metal cladding (b) Impressed current method (c) Galvanization 3. Differentiate the following with suitable examples (a) Paints from varnishes. (b) Drying oils from non drying oils. 4. (a) Describe the free-radical polymerization of ethylene to polyethylene. (b) Write a note on i. Polymethyl methacrylate ii. Urea − Formaldehyde resins. 5. (a) Describe a method for estimating temporary hardness of water using Hehner’s procedure. (b) Outline the EDTA method for determining the permanent hardness of water. 6. (a) Explain the process of break-point chlorination. (b) What are its advantages ? (c) One litre of water from a borewell in Nellore showed the following analysis:Organic matter = 68 ppm; MgSO4 = 60 ppm; CaSO4 = 68 ppm; Mg(HCO3 )2 = 40.5 ppm; Ca(HCO3 )2 = 73 ppm. Calculate the amount of lime and soda required in kgs to soften 20,000 litres of this water if the lime used is 80% pure and soda is 90% pure. 7. (a) Differentiate between electrical insulators and dielectrics. (b) Outline the important applications of thermal insulators. 8. Explain the hardening and setting of cement using the chemical equations. ????? 1 of 1

Set No.3

Code No: RR10104 I B.Tech.

Time: 3 hours

Regular Examinations, June -2005 APPLIED CHEMISTRY (Civil Engineering) Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ?????

1. Explain the mechanism of corrosion when (a) Two dissimilar metals are connected and exposed to electrolyte (b) A metal exposed to varying aeration. 2. Explain the various methods of cleansing articles before electroposition and their advantages 3. (a) Why is anodizing best suited for aluminium? (b) How will you differentiate a paint from varnish and lacquers? 4. Describe the structure, preparation and uses of (a) Bakelite (b) Nylon (6,6) 5. (a) What are ion-exchange resins ? (b) Describe the softening of hard water using ion-exchange resins. 6. (a) Discuss the sterilization of drinking water by Chlorination. (b) A sample of water obtained from Karimnagar showed the following analysis: CaCl2 = 11.1 ppm; Mg(NO3 )2 = 14.8 ppm; MgSO4 = 12 ppm; Ca(HCO3 )2 = 16.2 ppm; KCl = 7.45 ppm; Calculate the quantities in gms of lime and soda required to soften 5000 litres of this water. 7. (a) Explain i. thermal spalling and ii. porosity of refractories. (b) Write briefly on i. Silicone fluids and ii. SF6 in electrical industry. 8. (a) What is cement? How do you classify the cement? (b) Explain the different raw materials and mixing of the raw materials by the dry process during the manufacture of cement. ????? 1 of 1

Set No.4

Code No: RR10104 I B.Tech.

Time: 3 hours

Regular Examinations, June -2005 APPLIED CHEMISTRY (Civil Engineering) Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ?????

1. How are the following factors influence the rate of corrosion? (a) passive character of the metal. (b) over voltage. (c) volatility of corrosion products. 2. (a) What are anodic coatings and their advantages? (b) Explain the process of hot dipping of Zinc and Iron. 3. What is meant by chemical conversion coating? Explain the phosphate coating, chromate coatings and chemical oxide coatings. 4. (a) How are polymers classified based on i. tacticity and ii. nature of monomer. (b) Discuss the manufacture and uses of i. Buna-S rubber ii. Buna-N rubber 5. (a) What is caustic embrittlement ? (b) How can it be avoided. (c) Describe the Zeolite process for softening of water. 6. (a) What is break-point chlorination ? What is its importance ? (b) A sample of MgSO4.7H2 O was dissolved in water to make up one litre of the solution. 20ml of this solution, when titrated volumetrically required 20ml of 0.2 M standard EDTA solution using EBT indicator. Determine the hardness of this solution in terms of CaCO3 in ppm units. 7. (a) Outline the important characteristics of refractories. (b) Differentiate between the different types of insulating materials. (c) Explain the use of silicone fluids as insulating materials. 8. Explain the chemistry of the manufacture of cement by wet process. ?????

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