lecture Water technology

www.Vidyarthiplus.com Unit-1 Water Technology The process of removing all types of impurities from water of impurities from water and making fit for domestic (or)industrial purpose is called water technology Types of impurities in water: The impurities present in water may be broadly classified into three types (i)Physical impurities (a) Suspended impurities (b) Colloidal impurities (ii) Chemical impurities (a) Dissolved salts (b)Dissolved gases (iii) Bacterial impurities Boiler feed water The water fed into the boiler for the production of steam is called boiler feed water Requirements Boiler feed water should be free from turbidity, oil, dissolved gases, alkali and hardness causing substances Hard water: Which does not produce lather with soap soln,but produce white ppt(scum) is called hard watetr 2C17H35COONa +Ca ++ → (C17H35COO)2Ca + 2Na+ Soft water: www.Vidyarthiplus.com www.Vidyarthiplus.com Which produce lather readily with soap soln is called soft water Absence of Ca&Mg salts Types of hardness: 1.Temporary hardness 2.permanent hardness Units of hardnss: Parts per million(ppm) It is defined as the no.of parts of CaCo3 eqivalent hardness per 10 parts of water Milligram per litre(mg/lit) It is defined as the no.of milligrams of CaCO3 hardness per litre of water equivalent Clarke’s degree( Cl) It is defined as the no.of parts of CaCO3 equivalent hardness per 10 parts of water French degree( Fr) It is defined as the no.of parts of CaCO3 equivalent hardness per 10 part of water 1ppm=1mg/lit=0.10Fr=0.070cl Alkalinity determination: www.Vidyarthiplus.com www.Vidyarthiplus.com PRINCIPLE Alkalinity in water is due to the presence of soluble hydroxides, bicarbonates and carbonates Alkalinity can be determined by Potentiometric methods Using pH meter Titrimetry using different indicators Determination of various types and amounts of alkalinity is easily carried out by titration with standard HCl employing the indicators phenolphthalein and methyl orange independently or in succession The following reactions occur when different types of alkalinity are neutralized with acid OH- + H+  H2O CO32- + H+ HCO3- + H+ 4.2-5.5 -(3) completed at pH 8.2-9.0 - (1)  HCO3- (2)  (H2CO3)  H2O + CO2 , completed at pH Neutralisation (1) & (2) will be notified by phenolphthalein endpoint while all the three will be accounted by methyl orange endpoint Bicarbonate in eqn (3) may be due to the existence of soluble free bicarbonate salts or bicarbonates resulting from half www.Vidyarthiplus.com www.Vidyarthiplus.com neutralization of soluble carbonates (eqn (2))Various steps to be followed: A known volume of water sample is titrated against std HCl using first phenolphthalein indicator till end-point (P) and the titration is continued without break using methyl orange indicator till the equivalence end-point (M) From the magnitudes of the P & M, the nature of alkalinity can be arrived as follows: (i) P = M => Presence of only OH- (ii) 2P = M => Presence of only CO32- (iii) P =0, M#0 => Presence of only HCO3- (iv) 2P > M => Presence of OH- & CO32- (v) 2P < M => Presence of HCO3- & CO32- (Mixture of OH- & HCO3-are not listed since they not exist together and are considered equivalent to CO32-) PROCEDURE www.Vidyarthiplus.com www.Vidyarthiplus.com TITRATION – I STANDARDISATION OF HCl Exactly 20 ml of the given standard NaOH solution is pipetted out into a clean conical flask and drops of phenolphthalein indicator is added The solution is titrated against the given HCl taken in the burette The pink colour of the solution in the conical flask disappears at the endpoint The titre value is noted down from the burette and the titration is repeated to get concordant value TITRATION – II ESTIMATION OF ALKALINITY IN WATER SAMPLE Exactly 20 ml of water sample is pipetted out into a clean conical flask Few drops of phenolphthalein indicator are added and titrated against the standardized HCl taken in the burette The end-point is the disappearance of pink colour, which is noted as P Into the same solution few drops of methyl orange indicator is added The solution changes to yellow The titration is continued further by adding same HCl without break till the end-point is reached The end point is the colour change from yellow to reddish orange The titre value is noted as M The experiment is repeated to get concordant values From the magnitudes of P & M values, the type of alkalinity present in the water sample is inferred and the individual amounts are calculated and reported www.Vidyarthiplus.com www.Vidyarthiplus.com Estimation of hardness by EDTA method: EDTA:ethylene diammine tetra acetic acid (CH2COOH )2N-CH2-CH2-N(CH2COOH)2 Principle: Hadness causing ions (Ca2+,mg2+)estimatimated by titrating the water sample against EDTA Indicator: eriochrome –black –T Buffer soln: (NH4Cl-NH4OH):PH:8-10 www.Vidyarthiplus.com www.Vidyarthiplus.com *Ca2+,Mg2+++EBT→*Ca,Mg EBT+ complex(wine red coloured weak complex) *Ca ,Mg EBT+Complex +EDTA→*Ca Mg EDTD++EBT(Steel blue) The estimation is based on the complexometric titration (i) Total hardness of water is estimated by titrating it against EDTA using EBT indicator EBT+Mn+ [EBT-M] (complex) EBT-M (unstable complex) +EDTA  [EDTA-M] (stable complex) +EBT (Wine red) (Steel blue) EBT indicator forms wine red coloured complex with hardness causing metal ions present in water On addition of EDTA, metal ions preferably form complexes with EDTA and steel blue EBT indicator is set free Therefore change of colour from wine red to steel blue denotes the end point (iii) Temporary hardness is removed by boiling the water www.Vidyarthiplus.com www.Vidyarthiplus.com Ca (HCO3)2  CaCO3 ↓+CO2 +H2O Mg (HCO3)2  Mg(OH)2 ↓ +2CO2 The precipitate is filtered and the remaining permanent hardness is estimated using EDTA Pipette out 20ml of standard CaCl2 into a 250ml conical flask (Standard hard water is prepared by dissolving g of calcium carbonate in one litre of distilled water) Add 5ml of buffer solution and drops of eriochrome black T indictor Titrate the solution with EDTA from the burette until the colour changes from wine red to steel blue at the end point Repeat the titration for concordant values Let the titre value be V1ml TITRATION – II (ii) DETERMINATION OF TOTAL HARDNESS Pipette out 20ml of sample hard water into a clean conical flask Add 5ml of buffer solution and -5 drop of eriochrome black T indicator Titrate the wine red coloured solution with EDTA from the www.Vidyarthiplus.com www.Vidyarthiplus.com burette until the colour steel blue appears at the end point Repeat the titration for concordant values Let the titre value be V2ml TITRATION – III (iii)DETERMINATIONOF PERMANENT HARDNESS Take 250ml of hard water sample in a 250ml beaker and boil gently for about 20 minutes Cool, filter it into a 250ml standard flask and make the volume upto the mark Take 20ml of this solution and proceed it in the same way as in titration (I) The volume of EDTA consumed corresponds to the permanent hardness of the water sample Let the titre value be V3ml Temporary hardness is calculated by subtracting permanent hardness from total hardness Step 1- Arriving at standard equation, 1ml of Std CaCl = mg of CaCO3 ( given) V1 ml of EDTA = 20 ml of Std CaCl ml of EDTA = (20 / V1) ml of Std CaCl www.Vidyarthiplus.com www.Vidyarthiplus.com Therefore, ml of EDTA = (20 / V1) mg of CaCO3 equation.) (standard Step 2.- Calculation of total hardness Volume of EDTA consumed (V2) = ml 20ml of sample hard water = V2 ml of EDTA 1000 ml of sample hard water =V2X(1000/20) ml of EDTA As per standard equation,100ml of given hard water = V2 X (1000/20) X (20 / V1) mg of CaCO3 =1000 x (V2 / V1 ) mg of CaCO3 Therefore, total hardness = ppm www.Vidyarthiplus.com www.Vidyarthiplus.com Unit-V PART A Explain Moh’s scale for different abrasives What is hardness of abrasives? Give its units What is emery? What is meant by refractoriness of refractory? How are refractories classified? Give examples for each type What is RUL? Define viscosity index Define lubrication What is Extreme Pressure lubrication? 10.Define cloud and pour point 11.What is the significance of oilness? 12.What are soft abrasives? 13.What is abrasive power? 14.How are abrasives used? 15.What is diamond? Mention its types 16.Define liquid lubricants 17.What is acid refining process? 18.Define blended oil 19.Differenciate between oildag and aquadag 20.What should be flash point of a good lubricant? PART B silicon carbide bricks prepared? Give it properties and uses (8) What is carborundum? Give preparation properties of Boron carbide (8) Describe the any four properties of refractories (8) Discuss the manufacture and properties of alumina and magnesite bricks (8) Write note on flash and fire point Give its significance.(8) Discuss the mechanism of thick film (Hydrodynamic) and thin layer (Boundary layer) of lubrication (8) What are solid lubricants? When are they used? Explain the structure of any one solid lubricant (8) How does Graphite act as a good lubricant? Explain (8) Explain the types of lubricants (8) 10.Draw the structure and functions of Molybdenum disulphide (8) www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Semester Supplimentary Examinations, June 2009 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ Give an account of the various methods involved in the treatment of potable water [16] (a) Explain the cold lime soda process and hot lime soda process What are the advantages of lime soda process? (b) 100 ml of a water sample contains hardness equivalent to 25 ml of 0.08 N MgSO4 [8+8] i What is the hardness of water sample in ppm? ii What is the amount of lime and soda required for the treatment of the water sample? Write short notes on the following: (a) Cathodic protection (b) Caustic embrittlement corrosion [8+8] Discuss the following: [16] (a) Galvanization (b) Cementation (c) Chromizing (a) Identify the thermo sets and thermoplastics among the following: i PVC ii Polyethylene iii Silicone iv Polyester fibre v Bakelite (b) What is bakelite? How is it manufactured and mention its uses? [5+11] (a) Bring out the differences between fluid film and boundary lubrications (b) What is online point? Mention its significance (c) Write a short note on thin-film lubrication [5+5+6] (a) What is meant by the term lubrication ? (b) Define the following: i lubricant ii Friction iii Seizure (c) What is surface roughness, surface attraction and surface energy? [2+8+6] (a) Explain the recovery of by-product from ‘Coke oven gas’ (b) Give the comparison between solid, liquid and gaseous fuels [8+8] www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Semester Supplimentary Examinations, June 2009 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks (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] Explain the basic principle, different methods, advantages and disadvantages of lime-soda process [16] Explain how corrosion control can be brought about by the following methods (a) Modifying the environment (b) Cathodic protection [8+8] Explain the following terms: [16] (a) Drying oil (b) Thinners (c) Driers (d) Fillers (a) What are heterochain polymers? Give examples (b) What are Antioxidants? How are they useful in compounding of resins? (c) Write a note on Buna- N Rubber [4+6+6] Write a note on lubricants with special reference to their classification, mode of action, examples and applications [16] Describe the various types of lubrication [16] (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] www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Semester Supplimentary Examinations, June 2009 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks (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] Write short notes on the following: [16] (a) Colloidal conditioning (b) Sodium aluminate condition (c) Calgon conditioning (d) Carbonate conditioning Give an account of any eight factors that influence the rates of corrosion [16] Write note on: [16] (a) Phosphate coatings (b) Chemical oxide coatings (c) Anodized coatings (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] Write a note on lubricants with special reference to their classification, mode of action, examples and applications [16] (a) What are the functions of lubricants? (b) Write a note on extreme pressure lubrication [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] www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Semester Supplimentary Examinations, June 2009 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ (a) What is hardness of water? How you express the hardness? What are the units to express the hardness? (b) Give an account of the disadvantages of hard water [8+8] (a) What is meant by desalination? What is its significance? (b) Explain the different methods used for the desalination of brackish water [4+12] (a) Give an account of the various factors which influence the rate of corrosion (b) Write a brief account on pilling-bedworth rule [8+8] Explain the following terms: [16] (a) Drying oil (b) Thinners (c) Driers (d) Fillers (a) What is Nylon and how is it prepared? (b) Explain any one of the mechanism of addition polymerization Using a suitable example (c) Describe the important uses of PVC [6+6+4] (a) Define flash and fire points (b) Discuss the important functions of lubricants [16] (a) What is meant by the term lubrication ? (b) Define the following: i lubricant ii Friction iii Seizure (c) What is surface roughness, surface attraction and surface energy? [2+8+6] (a) What is Transportation theory? Explain? (b) What is coal? How it is formed? (c) Explain the classification of coal [3+4+9] www.Vidyarthiplus.com www.Vidyarthiplus.com B.E/B.TECH DEGREE EXAMINATION, JANUARY 2010 FIRST SEMESTER ENGINEERING CHEMISTRY-I (REGULATION 2008) PART A (10X2=20 MARKS) Calculate the hardness of a water sample containing 2.4 mg of calcium chloride in 500 ml of water? What is Calgon?how does it function in water treatment? Why thermosetting plastics can not be remoulded? What is the role of Sulphur in the vulcanization of rubber? Compare absorption and adsorption Mention any four applications of adsorption Furnish the sequence of reactions in proton cycle nuclear fusion Give any two advantages of alkaline battery over dry cell Define refractoriness of a refractory 10 What are nano materials? Mention any two of their characteristic properties PART B-(5 X 16=80) 11.i How is temporary hardness of water estimated by EDTA method? ii What are the requirements of potable water? How will you purify water for drinking purpose? Or 12.i What are ion exchange resins? How are they useful in removing hardness of water? ii What is desalination? With a neat diagram, describe the 'reverse osmosis' method for the desalination of brackish water 13.i how are the following polymers prepared? Teflon Polystyrene PET Nylon 6, ii Explain the mechanism of free radical addition polymerization www.Vidyarthiplus.com www.Vidyarthiplus.com Or 14.i What is natural rubber? Explain why natural rubber needs vulcanization How is it carried out? ii What are composites? Give the preparation and uses of glass fiber reinforced composites and carbon fiber reinforced composites 15.i Compare physisorption and chemisorption ii Adsorption of gases on solids is greatly influenced by temperature,pressure and nature of the adsorbent and adsorbate.justify Or 16.i Describe the role of adsorbents in catalysis with examples ii How is ion exchange adsorption useful in demineralization of water? Explain 17.i Explain with a neat diagram the parts and functions of a nuclear reactor ii Write a note on photovoltaic cell Or 18.i Explain the working of hydrogen oxygen fuel cell ii Write a short note on lithium batteries 19.i How are alumina and carborundum manufactured? ii What are refractories?how are they classified? Or 20.i What are fluid and boundary lubrication? Explain ii What are carbon nano tubes? Explain any three of their important applications? www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Supplimentary Examinations, Aug/Sep 2008 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ (a) What is hardness of water? How you express the hardness? What are the units to express the hardness? (b) Give an account of the disadvantages of hard water [8+8] Write short notes on the following: [16] (a) Carry over (b) Ion-exchange process (a) Give an account of the various factors which influence the rate of corrosion (b) Write a brief account on pilling-bedworth rule [8+8] Write note on: [16] (a) Phosphate coatings (b) Chemical oxide coatings (c) Anodized coatings (a) Identify the thermo sets and thermoplastics among the following: i PVC ii Polyethylene iii Silicone iv Polyester fibre v Bakelite (b) What is bakelite? How is it manufactured and mention its uses? [5+11] Write a note on lubricants with special reference to their classification, mode of action, examples and applications [16] Describe the various types of lubrication [16] (a) Describe the ultimate analysis of coal and its significance (b) Describe the manufacture of coke by Beahive oven method with a neat diagram [8+8] ⋆⋆⋆⋆⋆ www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Supplimentary Examinations, Aug/Sep 2008 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks Write a brief account on the following: (a) Alkalinity of water (b) Complexometric method of estimation of hardness of water [8+8] (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] Write short notes on: (a) Galvonic corrosion (b) Concentration cell corrosion [8+8] Explain different types of Metallic Coatings [16] (a) What are the draw backs of raw rubber? How are its properties improved? (b) How is Buna - S Rubber prepared? Write its uses [8+8] Write a note on lubricants with special reference to their classification, mode of action, examples and applications [16] Discuss the various types of liquid lubricants [16] A petrol sample contains 84% carbon and 16% Hydrogen by weight Its flue gas composition by volume is CO2 = 12.1%, CO = 1.0%, Oxygen = 1.4% and N2 = 85.5% Calculate (a) minimum air for complete combustion of 1.0 kg of petrol (b) Actual air supplied per kg of petrol and (c) the C.V of the petrol sample [16] ⋆⋆⋆⋆⋆ I B.Tech Supplimentary Examinations, Aug/Sep 2008 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ Write a brief account on the following: (a) Treatment of water for drinking purpose (b) Determination of chlorides in water [8+8] (a) What is meant by desalination? What is its significance? www.Vidyarthiplus.com www.Vidyarthiplus.com (b) Explain the different methods used for the desalination of brackish water [4+12] Justify the following statements by giving suitable examples (a) Electrochemical series gives a basis for the prediction of the process of corrosion (b) Design and material selection to help to control metallic corrosion [8+8] Explain the following terms: [16] (a) Drying oil (b) Thinners (c) Driers (d) Fillers (a) Identify the thermo sets and thermoplastics among the following: i PVC ii Polyethylene iii Silicone iv Polyester fibre v Bakelite (b) What is bakelite? How is it manufactured and mention its uses? [5+11] Write short notes on the following properties of lubricants (a) Pour point (b) Fire point (c) Neutralization number (d) Emulsification [4x4] (a) What are the functions of lubricants? (b) Write a note on extreme pressure lubrication [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] ⋆⋆⋆⋆⋆ www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Supplimentary Examinations, Aug/Sep 2008 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ (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] (a) Explain the method of softening of water by hot lime soda process (b) A sample of water contains the following dissolved impurities CaCO3 =100 ppm, Mg(HCO3)2 = 14.6 ppm, CaSO4 = 13.6 ppm, MgCl2 = 9.5 ppm, Al2 (SO4)3 =34.2ppm and silica = ppm Calculate the amount of lime and soda required for the purification of 1000 litres of water [8+8] (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 [8+8] Describe the process of dipping methods [16] (a) Describe the preparation properties and engineering uses of polyethylene (b) What is meant by Fabrication of plastics? Mention the different fabrication techniques [8+8] Explain the following two theories for the mechanism of the lubricants (a) Boundary lubrication (b) Extreme pressure lubrication [8+8] (a) What are the functions of lubricants? (b) Write a note on extreme pressure lubrication [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] ⋆⋆⋆⋆⋆ www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Supplimentary Examinations, Aug/Sep 2007 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ Write a brief account on the following: (a) Treatment of water for drinking purpose (b) Determination of chlorides in water [8+8] (a) What is meant by desalination? What is its significance? (b) Explain the different methods used for the desalination of brackish water [4+12] (a) What are electrochemical series? How are they useful in determining the rate of corrosion? (b) How you differentiate electrochemical series from galvanic series? [8+8] (a) What is Sheradizing? Explain and discuss its applications (b) Write note colirizing and chromizing [8+8] (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] Explain the following two theories for the mechanism of the lubricants (a) Boundary lubrication (b) Extreme pressure lubrication [8+8] (a) Discuss solid lubricants (b) Explain the mechanism of thin-film lubrication [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] ⋆⋆⋆⋆⋆ of www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Supplimentary Examinations, Aug/Sep 2007 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ (a) What is hardness of water? How you express the hardness? What are the units to express the hardness? (b) Give an account of the disadvantages of hard water [8+8] Compare the following processes (a) Permutit process with lime soda process (b) Phosphate conditioning with calgon conditioning [16] Explain the process of wet corrosion by evolution of hydrogen and absorption of oxygen [16] Differentiate the following with suitable examples [16] (a) Paints from varnishes (b) Drying oils from non drying oils (a) Write the repeat unit in Bakelite, PVC and Nylon? (b) Mention any two important compounding ingredients of rubber (c) Write a note on Silicones [5+6+5] Write a note on lubricants with special reference to their classification, mode of action, examples and applications [16] Describe the various types of lubrication [16] (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] ⋆⋆⋆⋆⋆ www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Supplimentary Examinations, Aug/Sep 2007 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ (a) What is the cause of hardness of water? How is the hardness of water expressed? (b) Explain the soap titration method for the estimation of total hardness of water (c) Calclulate the temporary hardness of water from the following data by the soap titration method, when 100 ml of the water sample is titrated with soap solution Leather factor = 0.6 ml soap solution Total hardness = 18.6 ml soap solution Permanent hardness = ml of soap solution Standard hardwater (400 mg/l of CaCO3) = 36 ml [4+6+6] (a) What is meant by desalination? What is its significance? (b) Explain the different methods used for the desalination of brackish water [4+12] Justify the following statements by giving suitable examples (a) Electrochemical series gives a basis for the prediction of the process of corrosion (b) Design and material selection help to control metallic corrosion [8+8] Explain the following terms: [16] (a) Drying oil (b) Thinners (c) Driers (d) Fillers (a) Discuss the compounding of plastics? (b) Explain the procedures used in the processing of Natural rubber (c) Write a note on urea formaldehyde resins [5+5+6] (a) Define flash and fire points (b) Discuss the important functions of lubricants [16] How to select lubricants for the following: [16] (a) cutting tools (b) I.C engines (c) steam engines (d) steam turbines (e) Gears (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] ⋆⋆⋆⋆⋆ www.Vidyarthiplus.com www.Vidyarthiplus.com I B.Tech Supplimentary Examinations, Aug/Sep 2007 ENGINEERING CHEMISTRY ( Common to Mechanical Engineering, Mechatronics, Production Engineering and Automobile Engineering) Time: hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ⋆⋆⋆⋆⋆ (a) What is meant by break point chlorination? What is its significance and advantages? (b) Explain the sedimentation process for the treatment of muncipal water [8+8] Write short notes on the following: [16] (a) Carry over (b) Ion-exchange process (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 [8+8] Explain different types of Metallic Coatings [16] (a) How is PVC prepared and what are its uses? (b) Write down the differences between compression and injection moulding techniques (c) How is Thiokol prepared? Mention its uses [4+6+6] Write a note on lubricants with special reference to their classification, mode of action, examples and applications [16] How to select lubricants for the following: [16] (a) cutting tools (b) I.C engines (c) steam engines (d) steam turbines (e) Gears (a) Explain the recovery of by-product from ‘Coke oven gas’ (b) Give the comparison between solid, liquid and gaseous fuels [8+8] ⋆ www.Vidyarthiplus.com [...]... hardness of water 2 What are the salts responsible for carbonate and non-carbonate hardness of water? 3 What is meant by soft water and hard water? 4 Distinguish hard and soft water 5 How the hardness of water is expressed? 6 Give the significance of calcium carbonate equivalent 7 How does EBT indicator function as an indicator in EDTA titration? 8 What is meant by permanent hardness of water? 9 Define... Why water is softened before using in boilers? 13 What are scales and sludges? 14 What is meant by priming and foaming? 15 How the caustic embrittlement is prevented? 16 Indicate the reasons for boiler corrosions 17 Define softening of water How it is carried out? 18 Soft water is demineralised water (DM) where as DM water is a soft water Justify 19 What is sodium Zeolite? 20 (a) What is aeration of water/ Mention... hardness of water is removed in zeolite process? Part-B 1 Describe the principle and method involved in the determination of different types and amount of alkalinity of water 2 Explain the EDTA method of estimation of hardness of water 3 What are boiler troubles? How are they caused? Suggest steps to minimize the boiler troubles 4 What is potable water? What are the steps taken to obtain pure drinking water? ... for sterlisizing water in swimming pool Cl2+H2O→HCl+HOCl Cl2+NH3→ClNH2+HCl ClNH2+H2O→HOCl+NH3 CaOCl2+H2O→Ca(OH)2+Cl2 Cl2+H2O→HCl+HOCl HOCl+Bacteria→bacterias are killed Break point chlorination: Water contains following impurities: 1.bacterias 2.organic impurities 3.redusing substances(Fe2+,H2S etc) www.Vidyarthiplus.com www.Vidyarthiplus.com 4.Free ammonia Boiler feed water: The water feed into the... adding Na2CO3 to the boiler water CaSO4+Na2CO3→CaCO3+Na2SO4 Phosphate conditioning: sodium phosphate scale formation can be avoided by adding 3CaSO4+2Na3po4→Ca3(po4)2 Trisodiumphospate Na3po4(Weaklyalkaline) used for too acidic water Disodium hydrogen phosphate-Na2HPO4(weakly alkaline) used for alka weakly acdic water Sodium dihydrogen phosphate-NaH2PO4(acidic) used for alkaline water www.Vidyarthiplus.com... in the water Process: Sodium ions with Ca2+ and Mg 2+ ions present in the water to form Ca and Mg ions present in the water Ca(HCO3)+Na2Ze→ CaZe+2NaHCO3 Mg (HCO3)+Na2Ze→ MgZe+2NaHCO3 CaSO4+ Na2Ze→ CaZe+Na2SO4 www.Vidyarthiplus.com www.Vidyarthiplus.com Mg SO4+ Na2Ze→ Mg Ze+Na2SO4 CaCl2 +Na2Ze→ CaZe+2NaCl Mg Cl2 +Na2Ze→ Mg Ze+2NaCl Regeneration: CaZe+2Na+Cl-→Na2Ze+CaCi2 Desalination of brackish water: ... Ze+2NaCl Regeneration: CaZe+2Na+Cl-→Na2Ze+CaCi2 Desalination of brackish water: The process of removing common salt from the water is known as desalination 1.Fresh water -1000ppm but 35000ppm of dissolved solids Reverse osmosis(RO) Two solns of different concentrations are separated by a semi... ml 20ml of boiled water = V3 ml of EDTA 1000 ml of boiled water =V3 X (1000/20) ml of EDTA As per standard equation, 1000ml of given hard water= V3 X /V1) mg of CaCO3 (1000/20) X (20 = 1000 x (V3 / V1 ) mg of CaCO3 Therefore, permanent hardness = ppm Step 4 – Calculation of temporary hardness www.Vidyarthiplus.com www.Vidyarthiplus.com Temporary hardness of the given sample of water = Total hardness... hardness =ppm Treatment of water for domestic supply : Screening: It is a process of removing the fioating material like leaves,woodpieces,etc.from water Aeration: The process of mixing water with air is known as aeration To remove gases like CO2,H2S www.Vidyarthiplus.com www.Vidyarthiplus.com Sedimentation: It is a process of removing suspended impurities by allowing the water to stand un disturbed... bacteria,colour,taste,odour.passing water through filter beds Sterilization(or)disinfection: The process of destroying the harmful bacteria is known as sterilization By boiling: www.Vidyarthiplus.com www.Vidyarthiplus.com Water boiled for 10-15minitues all the harmful bacteria are killed and the water becomes safe for use By ozonation O3→O2+[O] Ozone is a powerful disinfectant and is readily absorbed by water, By using ... of water What are the salts responsible for carbonate and non-carbonate hardness of water? What is meant by soft water and hard water? Distinguish hard and soft water How the hardness of water. .. softening of water How it is carried out? 18 Soft water is demineralised water (DM) where as DM water is a soft water Justify 19 What is sodium Zeolite? 20 (a) What is aeration of water/ Mention... CaZe+2Na+Cl-→Na2Ze+CaCi2 Desalination of brackish water: The process of removing common salt from the water is known as desalination 1.Fresh water -1000ppm but