Applied Chemistry Textbook 2021 PDF

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Copyright © Reserved ISBN: 978-93-91505-44-8 No part of this publication may be Book Code: DIP121EN reproduced, stored in a retrieval system or transmitted, in any form or by any means, Applied Chemistry by Anju Rawlley, electronic, mechanical, photocopying, Devdatta Vinayakrao Saraf recording or otherwise without prior [English Edition] permission of the publisher. This book is sold subject to the condition First Edition: 2021 that it shall not, by way of trade, be lent, re-sold, hired out or otherwise disposed Published by: of without the publisher’s consent, in any form of binding or cover other than that in Khanna Book Publishing Co. (P) Ltd. which it is published. Visit us at: www.khannabooks.com Write us at: [email protected] Disclaimer: The website links provided by CIN: U22110DL1998PTC095547 the author in this book are placed for informational, educational & reference To view complete list of books, purpose only. The Publisher do not Please scan the QR Code: endorse these website links or the views of KPH the speaker/ content of the said weblinks. In case of any dispute, all legal matters Printed in India to be settled under Delhi Jurisdiction only.  ACKNOWLEDGEMENT The author(s) are grateful to AICTE for their meticulous planning and execution to publish the technical book for Diploma Engineering students. We sincerely acknowledge the valuable contributions of the reviewer of the book Prof. Sunita Mukesh Patil, for making it students’ friendly and giving a better shape in an artistic manner. This book is an outcome of various suggestions of AICTE members, experts and authors who shared their opinion and thoughts to further develop the engineering education in our country. It is also with great honour that we state that this book is aligned to the AICTE Model Curriculum and in line with the guidelines of National Education Policy (NEP) -2020. Towards promoting education in regional languages, this book is being translated in scheduled Indian regional languages. Acknowledgements are due to the contributors and different workers in this field whose published books, review articles, papers, photographs, footnotes, references and other valuable information enriched us at the time of writing the book. Finally, we like to express our sincere thanks to the publishing house, M/s. Khanna Book Publishing Company Private Limited, New Delhi, whose entire team was always ready to cooperate on all the aspects of publishing to make it a wonderful experience. Anju Rawlley Devdatta Vinayakrao Saraf (v)  Preface Chemistry has been used for understanding and solving the intricacies of life. The advancement in chemistry is closely associated with the well being of all human beings and has made the life simpler and comfortable. The textbook on “Applied Chemistry” has been developed as per AICTE model curriculum. This book is written, keeping in mind that basic concepts of chemistry should be comprehended in depth by budding diploma engineers, as these concepts may be applied in many of the engineering applications in industries and day to day life. The present text book is a sincere efforts in this direction. Efforts have been made to make this book useful and interesting for learning, in self-learning mode. The structure of the textbook is comprehensive, wherein sixteen practical exercises are integral part of each theory units, from one to five. Key feature of the book is that the text is presented in a very simple way with illustrations, examples, tables, flow charts, self-assessment questions with their solutions. Micro projects, points/issues for the creative inquisitiveness and curiosity, know more, video links, case study and summary points are integral part of different units to facilitate the students to develop the attitude of scientific inquiry, investigate the cause and effect relationship, systematic, scientific &logical thinking, ability to observe, analyse and interpret. All these abilities are essentially needed by diploma engineering passouts in the world of work. Details of practicals listed in the curriculum of each unit are mentioned in a systematic format for ease of performance and implementation by students, laboratory personnel and teachers. Laboratory practical format is comprising of practical significance, relevant theory, stepwise procedure, safety precautions, sample probing questions for viva- voce etc. To meet the requirement of outcome based education (OBE) and outcome based assessment (OBA), criterion referenced testing (CRT) have been used as an integral part of assessment in each practical. For this, specific and measurable criteria of process and product assessment with their percentage weightage is included in each experiment. This would enable students, teachers and evaluators to know the criterion of performance and assessment of each experiment for attainment of out comes. While every care has been taken to bring out this textbook error free. Nevertheless, there could inevitably be occasional errors. It would be our great pleasure to know from readers to make necessary modifications. Moreover, suggestions are welcome for the improvement of the book. Anju Rawlley Devdatta Vinayakrao Saraf (vii)  OUTCOME BASED EDUCATION Though, there are many challenges and issues in implementation and assessment of Outcome Based Education (OBE) and Outcome Based Curriculum (OBC), but the management and teachers need to ensure that the programme outcomes, as stated by NBA, for diploma engineering programme should be developed by the students, at the exit point of the diploma programme,through effective implementation and assessment of outcomes of different courses. The seven programme outcomes of the diploma engineering programme are as follows: PO1. Basic and Discipline Specific Knowledge: Apply knowledge of basic mathematics, science and engineering fundamentals and engineering specialization to solve the engineering problems. PO2. Problem Analysis: Identify and analyse well-defined engineering problems using codified standard methods. PO3. Design/ Development of Solutions: Design solutions for well-defined technical problems and assist with the design of systems components or processes to meet specified needs. PO4. Engineering Tools, Experimentation and Testing: Apply modern engineering tools and appropriate technique to conduct standard tests and measurements. PO5. Engineering Practices for Society, Sustainability and Environment: Apply appropriate technology in context of society, sustainability, environment and ethical practices. PO6. Project Management: Use engineering management principles individually, as a team member or a leader to manage projects and effectively communicate about well-defined engineering activities. PO7. Life-Long Learning: Ability to analyse individual needs and engage in updating in the context of technological changes. (ix)  Course Outcomes After completion of the course the students will be able to: CO-1: Solve various engineering problems applying the basic concepts of atomic structure, chemical bonding and solutions. CO-2: Use relevant water treatment method to solve domestic and industrial problems. CO-3: Solve the engineering problems using concepts of engineering materials and properties. CO-4: Use relevant fuel and lubricants for domestic and industrial applications. CO-5: Solve the engineering problems using concept of electrochemistry and corrosion. Course Expected Mapping with Programme Outcomes Outcomes (1-Weak Correlation; 2-Medium correlation; 3-Strong Correlation) PO-1 PO-2 PO-3 PO-4 PO-5 PO-6 PO-7 CO-1 3 2 1 1 2 1 1 CO-2 3 3 2 3 2 3 2 CO-3 3 2 3 3 3 2 2 CO-4 3 3 2 3 3 2 2 CO-5 3 2 2 2 2 2 2 (x)  Abbreviations and Symbols List of Abbreviations Abbreviations Full form Abbreviations Full form C.E. Chemical Equivalent TAN Total Acid Number or Equivalent Weight CO Course Outcome TEL Tetra Ethyl Lead EDTA Ethylene Diamine UO Unit Outcome Tetra Acetic acid HCV Higher Calorific Value VII Viscosity Index Improvers LCV Lower Calorific Value VM Viscosity Modifiers PO Programme Outcome Z or E.C.E. Electrochemical Equivalent RCC Reinforced Cement Concrete (xi)  List of Symbols Symbols Description n Principal Quantum Number l Angular Momentum or Azimuthal Quantum Number m Magnetic Quantum Number ms Spin Quantum Number Units Used Abbreviations Full form B.Th.U/ft3 British Thermal Units Per Cubic Foot B.Th.U./lb British Thermal Units Per Pound Cals/g Calories Per Gram C.H.U./lb Centigrade Heat Unit Per Pound 0 Cl 0Clark 0 Fr 0French K Kelvin K cals / kg Kilocalories Per Kilogram Kcal/m 3 Kilocalories Per Cubic Meter mg / L Milligrams Per Litre meq / L Milliequivalent Per Litre ppm Parts Per Million ppt Precipitate (xii)  List of Figures Unit 1 Figure Nos Titles of Figures Page.Nos. Fig. 1.1 Rutherford Experiment 3 Fig. 1.1(a) Gold Foil Experimention 3 Fig. 1.1 (b) Scattering of α-Rays through an Atom 3 Fig. 1.2 Bohr’s Representation of Forces acting on Electrons and Orbits in an Atom 4 Fig. 1.2 (a) Electrostatic Force of Attraction between Proton and 4 Electron Exactly equal to the Centrifugal Force Fig. 1.2 (b) Structure of Bohr’s Atom 4 Fig. 1.3 Jumping of an Electron after Absorbing and Emitting the Energy 5 Fig. 1.3 (a) Electron absorb Energy & Jump to Higher Energy Level 5 Fig. 1.3 (b) Electron Emits Energy & Jump to Lower Shell 5 Fig. 1.4. Hydrogen Spectrum Lines due to Jumping of Electrons 6 Fig. 1.5 Shape of s-Orbitals 7 Fig. 1.6 Dumbbell Shape of p-Orbitals 8 Fig. 1.7 Double Dumbbell Shape of d-Orbitals 8 Fig. 1.8 Importance of Chemical Compounds in Daily Life 13 Fig. 1.9 Lewis Structure of Ammonia 14 Fig. 1.10 Electrovalent Bond/Ionic Bond Formation due to Transfer of Electrons 16 Fig. 1.11 Lewis Dot Structure 18 Fig. 1.12 Formation of Hydrogen Molecule 18 Fig. 1.13 Types of Covalent Bond 19 Fig. 1.14 Comparison of Electrovalent and Covalent Bonding 20 Fig. 1.15 Orbital overlap along the Axis 22 Fig. 1.16 Formation of H2 molecule (s-s Overlapping) 22 Fig. 1.17 Formation of F2 Molecule (p-p Overlapping) 22 Fig. 1.18 Formation of HF Molecule (s-p Overlapping) 22 Fig. 1.19 Orbital Overlap Sidewise 22 Fig. 1.20 Formation of sp Hybrid Orbitals and Shape of BF3 Molecule 2 23 Fig. 1.21 Formation of sp Hybrid Orbitals & Shape of Methane (CH4) Molecule 3 23 Fig. 1.22 sp3 Hybridisation - NH3 24 (xiii) Fig. 1.23 sp3 Hybridisation-H2O 24 Fig. 1.24 Co-ordinate Bonding in NH4+ 25 Fig. 1.25 Hydrogen Bonding in Water Molecule 26 Fig. 1.26 Inter molecular H Bonding 27 Fig. 1.27 Delocalised Electrons in Metallic Bond 29 Fig. 1.28 Solute-Solvent-Solution 31 Fig. 1.29 Concentration of Solution 31 Unit 2 Fig.2.1 Earths Water 50 Fig.2.2 Fresh Water 50 Fig.2.3 Surface Water 50 Fig.2.4 Sludge Formation 55 Fig. 2.5 Scale Formation 55 Fig. 2.6 Removal of Dissolved Oxygen by Heating 58 Fig. 2.7 Ethylene Diamine Tetra Acetic Acid (EDTA) 60 Fig. 2.8 Ca EDTA Complex 2+ 60 Fig. 2.9 Intermittent Type Softener 64 Fig. 2.10 Continuous Type Softener 64 Fig. 2.11 Continuous Type Hot Soda lime softener 65 Fig. 2.12 Zeolite Softener 65 Fig. 2.13 Demineralization of Water 69 Fig. 2.14 Sand Filter 72 Fig. 2.15 Vertical Pressure Filter 73 Fig. 2.16 Chlorinator 74 Fig. 2.17 Ozonolysis Method 76 Unit 3 Fig. 3.1 Ore and Mineral 95 Fig. 3.2 An Ore 95 Fig. 3.3 Crushing and Grinding of Ore 96 Fig. 3.4 Gravity Separation 97 Fig. 3.5 Froth Flotation Process 97 Fig. 3.6 Magnetic Separation 97 Fig. 3.7 Alumino Thermic Process 100 Fig. 3.8 Electrolytic Refining of Copper 101 (xiv) Fig. 3.9 Reverberatory Furnace 102 Fig. 3.10 Blast Furnace 103 Fig. 3.11 Electrolysis of Bauxite 108 Fig. 3.12 Purification of Aluminium 108 Unit 4 Fig. 4.1 Structure of Graphite 149 Fig. 4.2 Thick Film Lubrication 151 Fig 4.3 Boundary Film Lubrication 151 Fig. 4.4 Viscosity 152 Unit 5 Fig. 5.1 Faraday’s Second Law of Electrolysis 179 Fig. 5.2 Extraction of Sodium 181 Fig. 5.3 Electroplating 182 Fig. 5.4 Electrolytic Refining of Copper 183 Fig. 5.5 Primary Cell 185 Fig. 5.6 Lead Acid Storage Cell 186 Fig. 5.7 Hydrogen Oxygen Fuel Cell 188 Fig. 5.8 Photovoltaic Solar Cell 189 Fig. 5.9 Corrosion by Oxygen 191 Fig. 5.10 Wet or Electrochemical Corrosion 192 Fig. 5.11 Oxygen Absorption Type 193 Fig. 5.12 Sacrificial Anodic Protection Method 198 Fig. 5.13 Galvanizing (Zinc Coating on Iron) 199 (xv)  List of Tables Unit 1 Tables Nos Titles of Tables Page. Nos. Table 1.1 Appearance of Hydrogen Spectrum in Different Region 6 Table 1.2 Magnetic Quantum Number 10 Table 1.3 Four Quantum Numbers for First 10 Electrons in [Ne] 10 Table 1.4 Pairing Arrangement of Electrons Permitted by Hund’s Rule 11 Table 1.5 Orbital Electronic Configuration of Elements up to Atomic No. 11 12 Table 1.6 Combining Capacity of Different Elements 13 Table 1.7 Types of Bonds 15 Table 1.8 Participation of Electrons in Covalent Bond Formation 19 Table 1.9 Properties and Comparison of Electrovalent and Covalent Compounds 20 Table 1.10 Types of Hybridisation 23 Table 1.11 Difference between Hydrogen Bond and Covalent Bond 28 Table 1.12 Difference between Metallic Bond and Ionic Bond 29 Unit 2 Table 2.1 Difference between Soft Water and Hard Water 51 Table 2.2 Relation between Various Units of Hardness 53 Table 2.3 Difference between Sludge and Scale 56 Table 2.4 Calculation of Alkalinity of water 62 Table 2.5 Comparison between the Zeolite Process & Soda-Lime Process 67 Table 2.6 Organoleptic and Physical Parameters for Drinking Water 77 Table 2.7 Bacteriological Quality of Drinking Water 78 Table 2.8 General Parameters Concerning Substances Undesirable in Excessive Amounts 78 Unit 3 Table 3.1 Difference between Minerals and Ore 95 Table 3.2 Ores of Iron, Aluminium and Copper 95 Table 3.3 Composition, Properties and Uses of Some Alloys of Copper 110 Table 3.4 Composition, Properties and Uses of Some Alloys of Iron 110 Table 3.5 Composition, Properties and Uses of Some Alloys of Aluminium 111 (xvi) Table 3.6 Composition of Portland Cement 112 Table 3.7 Average Compound Composition of Portland Cement 112 Table 3.8 Composition of Glass 115 Table 3.9 Types of Glasses and their Uses 115 Table 3.10 Composition, Properties and Uses of Refractories 116 Table 3.11 Composite Classification Based on Types of Matrix & Reinforcement 117 Table 3.12 Polymerisation Reactions and their Uses 118 Table 3.13 Difference between Thermoplastics and Thermosetting Plastics 120 Table 3.14 Difference Between Natural Rubber and Vulcanised Rubber 121 Unit 4 Table 4.1 Classification of Fuels 139 Table 4.2 Higher Calorific Values of Fuel Constituents 140 Table 4.3 Octane Rating of some Common Hydrocarbon 143 Table 4.4 Composition, Calorific Values and Applications of Fuels 144 Table 4.5 Liquid Lubricants: Classification their Properties 147 Table 4.6 Classification and Properties of Semi Solid Lubricants 148 Unit 5 Table 5.1 Strong Electrolyte & Weak Electrolyte 178 Table 5.2 Difference between Electrolytic cell and Electrochemical Cell 187 Table 5.3 Difference between Dry/ Chemical and Wet/ Electrochemical Corrosion 194 (xvii)  Some Ionic Compounds (Electrovalent Compounds) Sr.No Name Formula Ions present 1. Sodium Chloride NaCl Na+ and Cl– 2. Potassium Chloride KCl K+ and Cl– 3. Ammonium Chloride NH4Cl NH4+ and Cl– 4. Magnesium Chloride MgCl2 Mg2+ and Cl– 5. Calcium Chloride CaCl2 Ca2+ and Cl– 6. Sodium Oxide Na2O Na+ and O2– 7. Magnesium Oxide MgO Mg2+ and O2– 8. Calcium Oxide CaO Ca++ and O2– 9. Aluminium Oxide Al2O3 Al3+ and O2– 10. Sodium Hydroxide NaOH Na+ and OH– 11. Copper Sulphate CuSO4 Cu2+ and SO42– 12. Calcium Nitrate Ca(NO3)2 Ca2+ and NO3– 13. Aluminium Chloride AlCl3 Al3+ and Cl– Some Covalent Compounds Sr. No. Name Formula Present Atoms 1. Methane CH4 C and H 2. Ethane C2H6 C and H 3. Ethylene C2H4 C and H 4. Ethyne (Acetylene) C2H2 C and H 5. Water H2O H and O 6. Ammonia NH3 N and H 7. Ethyl Alcohol (Ethanol) C2H5OH C, H and O 8. Hydrogen Chloride Gas HCl H and Cl 9. Hydrogen Sulphide Gas H2S H and S 10. Carbon Dioxide CO2 C and O 11. Carbon Disulphide CS2 C and S 12. Carbon Tetrachloride CCl4 C and Cl 13. Glucose C6H12O6 C, H and O 14. Cane Sugar C12H22O11 C, H and O 15. Urea CO(NH2)2 C, O, N and H 16. Benzene C6H6 C and H 17. Hydrogen Gas H2 H 18. Chlorine Gas Cl2 Cl 19. Oxygen gas O2 O (xviii)  Some Common Salts Present in Water Sr.No Name Formula Ions present 1 Calcium Carbonate CaCO3 Ca2+ and CO32– 2 Magnesium Carbonate MgCO3 Mg2+ and CO32– 3 Calcium Bicarbonate Ca(HCO3)2 Ca2+ and HCO3– 4 Magnesium Bicarbonate Mg(HCO3)2 Mg2+ and HCO3– 5 Calcium Chloride CaCl2 Ca2+ and Cl– 6 Magnesium Chloride MgCl2 Mg2+ and Cl– 7 Calcium sulphate CaSO4 Ca2+ and SO42– 8 Magnesium sulphate MgSO4 Mg2+ and SO42– 9 Ferrous Chloride FeCl2 Fe2+ and Cl– 10 Ferrous Sulphate FeSO4 Fe2+ and SO42– 11 Manganese Chloride MnCl2 Mn2+ and Cl- 12 Manganese Sulphate MnSO4 Mn2+ and SO42– 13 Calcium Silicate CaSiO3 Ca2+, Si4+ and O2– 14 Magnesium Silicate MgSiO3 Mg2+, Si4+ and O2– 15 Sodium Carbonate Na2CO3 Na+ and CO32– 16 Sodium Sulphate Na2SO4 Na+ and SO42– 17 Potassium Chloride KCl K+ and Cl– 18 Potassium Carbonate K2CO3 K+ and CO32– 19 Potassium Sulphate K2SO4 K+ and SO42– 20 Calcium Hydrogen Phosphates CaHPO4 Ca2+, HPO42– (xix)  Guidelines for Teachers To implement Outcome Based Education (OBE), knowledge level and skill set of the students should be enhanced. Teachers should take a major responsibility for the proper implementation of OBE. Some of the responsibilities (not limited to) for the teachers in OBE system may be as follows: Within reasonable constraint, they should manoeuvre time to the best advantage of all students. They should assess the students only upon certain defined criterion without considering any other potential ineligibility to discriminate them. They should try to grow the learning abilities of the students to a certain level before they leave the institute. They should try to ensure that all the students are equipped with the quality knowledge as well as competence after they finish their education. They should always encourage the students to develop their ultimate performance capabilities. They should facilitate and encourage group work and team work to consolidate newer approach. They should follow Blooms taxonomy in every part of the assessment. Bloom’s Taxonomy Teacher should Student should be Possible Mode of Level Check able to Assessment Students ability to Design or Create Mini project Creating create Students ability to Argue or Defend Assignment Evaluating Justify Students ability to Differentiate or Project/Lab Analysing distinguish Distinguish Methodology Students ability to Operate or Technical Presentation/ Applying use information Demonstrate Demonstration Students ability to Explain or Classify Presentation / Seminar Understanding explain the ideas Students ability to Define or Recall Quiz Remembering recall (or remember) (xx)  Guidelines for Students Students should take equal responsibility for implementing the OBE. Some of the responsibilities (not limited to) for the students in OBE system are as follows : Students should be well aware of each UO before the start of a unit in each and every course. Students should be well aware of each CO before the start of the course. Students should be well aware of each PO before the start of the programme. Students should think critically and reasonably with proper reflection and action. Learning of the students should be connected and integrated with practical and real life consequences. Students should be well aware of their competency at every level of OBE. (xxi)  CONTENTS Foreword iii Acknowledgement v Preface vii Outcome Based Education ix Course Outcomes xi Abbreviations and Symbols xii List of Figures xiii List of Tables xvi Guidelines for Teachers xx Guidelines for Students xxi Unit 1: Atomic Structure, Chemical Bonding and Solutions 1-47 Unit Specifics 1 Rationale 2 Pre-requisites 2 Unit Outcomes 2 1.1 Atomic Structure 2 1.1.1 An Introduction 2 1.1.2 Rutherford Model of an Atom 3 1.1.3 Bohr’s Theory 3 1.1.4 Hydrogen Spectrum Explanation Based on Bohr’s Model of an Atom 5 1.1.5 Heisenberg’s Uncertainty Principle 7 1.1.6 Orbital Concept and Shapes of s, p, d and f Orbitals 7 1.1.7 Quantum Numbers 9 1.1.8 Pauli’s Exclusion Principle 10 1.1.9 Hund’s Rule of Maximum Multiplicity 11 1.1.10 Aufbau Rule 12 1.1.11 Electronic Configuration 12 1.2 Chemical Bonding 13 (xxiii)  1.2.1 An Introduction, Concept &Causes 13 1.2.2 Types of Bonding 15 1.2.3 Ionic or Electrovalent Bond 15 1.2.4 Covalent bond (H2, F2, HF hybridization in BeCl2, BF3, CH4, NH3, H2O) 17 1.2.5 Coordinate bond 25 1.2.6 Hydrogen Bonding 26 1.2.7 Metallic Bonding 28 1.3 Solution 30 1.3.1 An Introduction 30 1.3.2 The idea of Solute, Solvent, and Solution 30 1.3.3 Methods to Express the Concentration of Solution 31 Solved Problems 32 Unit Summary 34 Exercises 36 Practicals 36-44 Know More 44 References and Suggested Readings 47 Unit 2 : Water 48-92 Unit Specifics 48 Rationale 48 Pre-requisites 49 Unit Outcomes 49 2.1 An Introduction 49 2.1.1 Graphical presentation of Water Distribution on Earth 50 2.1.2 Classification of Soft and Hard Water 50 2.1.3 Salts Causing Water Hardness 50 2.1.4 Unit of Hardness 52 2.2 Causes of Hard Water 53 2.2.1 Cause of Poor Lathering of Soap in Hard Water 53 2.2.2 Problems Caused by the Use of Hard Water in Boiler 54 2.2.3 Quantitative Determination of Water Hardness by ETDA Method 60 2.3 Water Softening Techniques 62 2.3.1 Water Softening Techniques –An Introduction 62 2.3.2 Soda Lime Process 63 (xxiv)  2.3.3 Zeolite Process 65 2.3.4 Ion Exchange Process for Water Softening 68 2.4 Municipal Water Treatment 71 2.4.1 Municipal Water Treatment- An Introduction 71 2.4.2 Screening 72 2.4.3 Sedimentation 72 2.4.4 Coagulation 72 2.4.5 Filtration 72 2.4.6 Disinfection / Sterilization 73 2.5 Indian Standard Specification of Drinking Water – An Introduction 77 2.6 Water for Human Consumption 79 Solved Problems 80 Unit Summary 82 Exercises 83 Practicals 83-91 Know More 91 References and Suggested Readings 92 Unit 3 : Engineering Materials 93-136 Unit Specifics 93 Rationale 93 Pre-requisites 93 Unit Outcomes 94 3.1 Introduction to Natural Occurrence of Metals 94 3.1.1 Minerals and Ores 94 3.1.2 General Principles of Metallurgy 96 3.1.3 Extraction of Iron from Haematite ore 102 3.1.4 Extraction of Aluminium from Bauxite 106 3.1.5 Alloys 109 3.2 General Chemical Composition, Composition Based Applications 111 3.2.1 Portland Cement 112 3.2.2 Glasses 114 3.2.3 Refractory 116 3.2.4 Composite Materials 116 (xxv)  3.3 Polymers 117 3.3.1 Preparation of Thermoplastics and Thermosetting Plastics 118 3.3.2 Rubber 120 3.3.3 Vulcanization of Rubber 120 Unit Summary 121 Exercises 122 Practicals 123-135 Know More 136 References and Suggested Readings 136 Unit 4 : Chemistry of Fuels and Lubricants 137 -174 Unit Specifics 137 Rationale 137 Pre-requisites 138 Unit Outcomes 138 4.1 Fuel and Combustion of Fuel- An Introduction 138 4.1.1 Fuel and Combustion 138 4.1.2 Classification of Fuels 139 4.1.3 Calorific Values (HCV and LCV) 139 4.1.4 Calculation of HCV and LCV using Dulong’s formula. 140 4.2 Analysis of Coal 141 4.2.1 Proximate Analysis of Coal (Solid Fuel) 141 4.2.2 Fuel rating of Petrol and Diesel (Octane and Cetane Numbers) 142 4.2.3 Chemical Composition, Calorific Values and Applications of Fuel 144 4.3 Lubrication – An Introduction 145 4.4 Functions of Lubricant 145 4.5 Characteristic Properties of Good Lubricant 146 4.6 Classification of Lubricants 146 4.6.1 Liquid Lubricants, Classification and Properties 146 4.6.2 Semi-solid Lubricants, Classification and Properties 148 4.6.3 Solid Lubricants, Classification and Properties 148 4.6.4 Emulsion 150 4.7 Mechanism of Lubrication 151 4.8 Physical Properties of Lubricant 152 (xxvi)  4.8.1 Viscosity 152 4.8.2 Viscosity Index 152 4.8.3 Oiliness 153 4.8.4 Flash Point and Fire Point 153 4.8.5 Cloud Point and Pour Point 154 4.9 Chemical Properties of Lubricants. 154 4.9.1 Coke Number or Carbon Residue 154 4.9.2 Total Acid Number (TAN) 155 4.9.3 Saponification Value (SV) or Saponification Number (SN) 156 Unit Summary 156 Exercises 157 Practicals 158-173 Know More 174 References and Suggested Readings 174 Unit 5 : Electro Chemistry 175–216 Unit Specifics 175 Rationale 175 Pre-requisites 176 Unit Outcomes 176 5.1 An Introduction 176 5.1.1 Electronic Concept of Oxidation-Reduction 176 5.2 Electrolytes and Non Electrolytes 178 5.2.1 Electrolytes 178 5.2.2 Non Electrolytes 179 5.2.3 Faradays Laws of Electrolysis 179 5.3 Industrial Application of Electrolysis 181 5.3.1 Electrometallurgy 181 5.3.2 Electroplating 182 5.3.3 Electrolytic refining. 183 5.4 Application of Redox Reactions in Electrochemical Cells 184 5.4.1 Primary cells – Dry cell 184 5.4.2 Secondary cell 185 5.4.2 (A) Lead Acid Storage Cell 185 (xxvii)  5.4.2 (B) Fuel Cell 187 5.4.2 (C ) Solar Cells. 189 5.5 Corrosion – An Introduction 190 5.5.1 Dry or Chemical Corrosion 191 5.5.2 Wet or Electrochemical Corrosion 192 5.6 `Factors influencing Rate of corrosion. 194 5.6.1 Nature of Metals 194 5.6.2 Nature of Corroding Environment 195 5.7 Internal Corrosion Preventive Measures 196 5.7.1 Purification 196 5.7.2 Alloying 196 5.7.3 Heat Treatment 197 5.8 External Corrosion Preventive Measures 197 5.8.1 Cathodic Protection 197 5.8.2 Anodic Protection 198 5.8.3 Organic Inhibitors 199 Solved Problems 200 Unit Summary 201 Exercises 202 Practicals 202-215 Know More 215 References and Suggested Readings 216 Appendices 217-218 Appendix- A : Records for Practicals 217 Annexures 219-221 Annexure - I General, Specific Instructions and Common Laboratory Glasswares 219 References for further learning 222 CO-PO Attainment Table 223 Index 225-227 (xxviii)  1 Atomic Structure, Chemical Bonding and Solutions UNIT SPECIFICS This unit comprises of the following major topics : Atomic structure Chemical bonding Solution The different concepts have been explained through examples for generating further curiosity and inquisitiveness and also developing creative problem solving abilities in the students, with the mention of their practical applications in the industries/day to day life. Assessment for learning at different intervals within the unit, at different levels of cognitive domain is carried out by designing formative assessment questions. For effective implementation of the outcome based curriculum in true spirit, wide spectrum of activities such as micro projects, assignments, industrial visits etc, are designed and integrated in the unit for the benefit and exposure of the students. Sample QR codes have been provided on various topics/sub topics for supplementary reading and reinforcing the learning. RATIONALE Diploma engineers need to understand the arrangement of all existing elements, the structural arrangement of fundamental particles, atoms and molecules. Theories put forward by different scientists in the form of laws and principles have been explained for understanding the structure of the atom. The chemical bonds are important in human physiology. The proteins and carbohydrates needed for our body are all result of chemical bonding between atoms. Oxygen we breathe, medicines we need are result of chemical bonding between atoms. It helps to explain how atoms are held together in different types of structures. The knowledge of chemical bonding and solution is extremely important to chemists, scientists, and every individual. Chemical bonding creates substances/compounds that everyone uses. It helps scientists to design new engineering materials and form chemical compounds with desirable properties for specific uses. Scientists could present 118 elements in the periodic table due to chemical bonding. While considering the future scenario, students have to work in different areas so as to comprehend the fundamental aspects such as bond formation and different anomalous behaviour of atoms, ions and molecules. 2 | Applied Chemistry PRE-REQUISITES Chemistry : Composition of matter Mathematics : Basic algebra and geometry Other : Basic ICT skills Unit Outcomes List of outcomes of this unit are as follows : U1-O1 Apply the different atomic theories, models and principles for structural illustration. U1-O2 Write the electronic configuration of different elements. U1-O3 Differentiate among the ionic, covalent and coordinate compounds based on the type of chemical bonding. U1-O4 Prepare the solution of given concentration (Normality, Molarity) Unit - 1 Expected Mapping of Unit Outcomes with the Course Outcomes Outcomes (1- Weak Correlation; 2- Medium Correlation; 3- Strong Correlation) CO-1 CO-2 CO-3 CO-4 CO-5 U1-O1 3 - - - - U1-O2 3 - - - - U1-O3 3 - - - - U1-O4 3 - - - - 1.1 ATOMIC STRUCTURE 1.1.1 An Introduction An atom is the smallest part of the existing universe. To understand the structure and arrangement of the smallest part of matter, thinkers and philosophers from all over the world put forward different theories for explaining the smallest particle of matter. In this unit, we will be learning about basic structure of atom, which is confirmed after performing different experiments. Interesting fact : The structure of an atom explained by Bohr is just like our solar system where the sun is at the centre and planets are revolving around it.  Atomic Structure,Chemical Bonding and Solutions | 3 1.1.2 Rutherford Model of an Atom In the early 1900, scientists from different countries tried to explain the structure of an atom. J.J. Thomson discovered the presence of electron in an atom in 1897, still he was unable to predict the structure of an atom. J.J Thomson won the Noble Prize of 1906 for the discovery of electrons. Gold Foil Screen of α-Particles Zinc Sulphide (ZnS) Beam of a-Particle Legend Ra Radioactive Element Deflected Rays Source of a-Particles 2He4 Undeflected Rays Lead box Scattered Rays (a) Gold Foil Experiment (b) Scattering of α- Rays through an Atom Fig. 1.1 : Rutherford Experiment Rutherford discovered the presence of proton in his famous gold foil experiment. Rutherford used Radium as a source of alpha particles which was placed inside the lead box. A beam of alpha particles bombarded on an ultra-thin gold foil and then the presence of undeflected, scattered and deflected alpha particles were recorded Rutherford over zinc sulphide (ZnS) screen due to its fluorescent nature as shown in [Fig. 1.1( a)]. Model of an He concluded that all of the positive charge and the majority of the mass of the Atom atom must be concentrated in a very small space in the centre of an atom, which he called the nucleus.[Fig. 1.1(b)]. The nucleus is the dense, central core of the atom and is composed of protons and neutrons which contribute nearly all of the mass of the atom. The electrons are distributed around the nucleus and occupy most of the volume of the atom. 1.1.3 Bohr’s Theory Bohr proposed his atomic model to overcome the drawbacks of Rutherford’s nuclear model. Bohr’s atomic model is based on the following postulates. An atom consists of a dense positively charged central part known as the nucleus which is at rest. The nucleus contains protons and neutrons combinedly called nucleons. The fixed circular path in which electrons revolve around the nucleus is Bohr’s known as orbits or shells. Model 4 | Applied Chemistry Orbits/Shells/ Centrifugal Force n=4 Energy levels acting on Electron n=3 Nucleus Electrostatic n=2 P+N Force of n=1 attraction N M L K + between Electron and Proton 2 Maximum number of 8 Electrons 18 32 (a) Electrostatic Force of Attraction (b) Structure of Bohr’s Atom between Proton and Electron Exactly equal to the Centrifugal Force Fig. 1.2 : Bohr’s Representation of Forces acting on Electrons and Orbits in an Atom Stationary orbits or non-radiating orbits are those orbits in which electrons do not radiate energy i.e. they are permitted to rotate without loss of energy. Permitted shells or orbits are those for which the angular momentum of the electron is an integral multiple of i.e. mvr =n , where n is a principal quantum number or shell number, momentum is nothing but the product of mass and velocity (mv), r is radius, h is Planks constant h = 6.626 x 10–34 J sec Angular momentum of an electron for n=1, 2, 3, 4…are respectively as mvr =1 , mvr =2 , mvr =3 , mvr = 4 … The shape of orbit is circular. Orbits are designated by K, L, M, N…. or denoted as 1, 2, 3, 4…. from the nucleus as shown in [Fig. 1.2 (b)]. The maximum capacity to accommodate electrons is given by formula 2n2, where n is orbit number. The electrostatic force of attraction between the nucleus and electron is exactly balanced by the centrifugal force as shown in [Fig. 1.2 (a)], that is why the electrons do not fall into the nucleus or do not go away from the orbit and hence the atom remains stable. *SAQ 1 The capacity of the shell to accommodate the maximum number of electrons is given by the formula 1. 1/2n2 2. 2n2 3. 3/2n2 4. 4/2n2 Key : 2  Atomic Structure,Chemical Bonding and Solutions | 5 SAQ 2 In the Rutherford experiment, the maximum number of undeflected particles represent that 1. maximum 2. maximum 3. maximum 4. maximum space of an number of number of positive number of atom is empty nucleus present charge present negative charge in an atom at the centre present at the centre Key : 1 SAQ 3 According to Bohr’s theory, the angular momentum of an electron for n = 4 is 1. 2. 3. 4. Key : 4 (*SAQ denotes Self Assessment Question) 1.1.4 Hydrogen Spectrum Explanation Based on Bohr’s Model of an Atom hv-(quanta) Emitted Energy (a) : Electron Absorbs Energy & (b) : Electron Emits Energy &Jump to Jump to Higher Energy Level Lower Energy Level Fig. 1.3 : Jumping of an Electron after Absorbing and Emitting the Energy When the electron absorbs energy, the electron moves from the lower energy level to a higher energy level. Jumped electrons are known as excited electrons. As shown in [Fig. 1.3 (a)] when an electron emits energy, electrons jump from a higher energy level to a lower energy level. The emitted energy is the difference of energies between two energy levels i.e. hn=Energy of electron present in higher energy level - Energy of electron present in lower energy level. Absorbed energy or released energy is in the form of quanta or photon only. The excited electron cannot jump along with high energy to lower energy orbitals. There is a difference in energies when an electron jumps from a higher energy level to a lower one. [Fig. 1.3 (b)]. When an electron emits energy it releases energy in the form of photons. i.e. E= hn. Due to loss of energy, there is a development of spectral lines of different frequencies which shows that distance between two different orbits is not equal. As we move away from the nucleus, the energy of orbits goes on increasing, while the distance between the orbits goes on decreasing. Jumping of the electron from one orbit to another orbit 6 | Applied Chemistry results in the emission of energy known as the transition of the electron. Transition frequency emitted in the form of the photon is given by Where RH is Rydberg’s Constant, ni is initial stationary orbit, nf is final stationary orbit. The wave numbers is reciprocal of the wavelength. Hence wave number of photons of the various spectral series are developed as shown in table 1.1 and [Fig. 1.4]. Bohr theory successfully accounts for the spectra of hydrogen and hydrogen like atoms like He+, Li2+, Be3+, B4+. Different spectrums are developed due to transition of electron from higher energy level to lower energy level. e.g. Lyman series is a spectral series for the transitions of electron from energy level 2 or 3 or 4 or… to first energy level. Similarly other series are developed (table 1.1) n=7 n=6 n=5 Humphreys series n=4 Pfund series Brackette series n=3 Paschen series n=2 Balmer series n=1 Lyman series Fig. 1.4.: Hydrogen Spectrum Lines due to Jumping of Electrons Table 1.1 : Appearance of Hydrogen Spectrum in Different Region Name of Series nf Electrons ≥ ni Electrons Appearing in Region Jumping at Jumping from Lyman Series 1 2, 3, 4 …. Ultraviolet region Balmer Series 2 3, 4, 5, 6…. Visible region Paschen Series 3 4, 5, 6, 7 … Infrared region Brackette Series 4 5, 6, 7,.. Infrared region Pfund Series 5 6, 7,... Infrared region Humphreys Series 6 7,8,…. Infrared region  Atomic Structure,Chemical Bonding and Solutions | 7 1.1.5 Heisenberg’s Uncertainty Principle It is not possible to determine precisely the exact position and momentum of moving electron simultaneously. Suppose Dx is uncertainty related to the position of an electron and Dp is the uncertainty related to the momentum of an electron. Mathematically it is stated as(Dx).(Dp) ≥ when (Dx) is tremendously small we can predict the approximate position of the particle at the same time Dp i.e. uncertainty related to momentum will be more. where Dx is the uncertainty in position and Dp is the uncertainty in momentum (or velocity) of the particle. If the position of the electron is known with high degree of accuracy (Dx is small), then the velocity of the electron will be uncertain [Dp is large]. On the other hand, if the velocity of the electron is known precisely (Dp is small), then the position of the electron will be uncertain(Dx will be large). Heisenberg won the Noble prize in 1932 for the creation of quantum mechanics, the application of which has led to the discovery of the allotropic forms of hydrogen. SAQ 4 “It is not possible to determine precisely the exact position and momentum of a small moving particle simultaneously “ is 1. Orbital 2. Aufbau 3. Pauli’s 4. Heisenberg’s Concept Principle Exclusion Principle Uncertainty Key: 4 1.1.6 Orbital Concept and Shapes of s, p, d and f Orbitals An orbit, as proposed by Bohr, is a fixed circular path around the nucleus in which an electron moves. A precise description of this path of the electron is impossible according to the Heisenberg uncertainty principle. An atomic orbital thus represents a region in three-dimensional space around the nucleus where there is a maximum probability of finding an electron of specific energy. There are four types of orbitals as follows : Y s-Orbital These orbitals are having spherical and non-directional Z shape [Fig. 1.5]. Each s orbital can accommodate 2 electrons in the opposite spin. One electron with +1/2 X spin, another electron with - 1/2 spin. In another way one with upward spin and another with downward spin or 1s one with clockwise spin another with counter-clockwise 2s (anticlockwise spin). Size of 1s is less than 2s orbital; 3s size of 2s is less than 3s orbital. Box Diagram Fig. 1.5 : Shape of s-Orbitals 8 | Applied Chemistry The empty region between two s-orbitals, where zero per cent probability of finding the electrons is known as the zero electron density region. p-Orbital There are three p- sub orbitals (px, py and pz ) orbitals having dumb-bell shape [Fig. 1.6]. These orbitals are directional and along the axis orbital. Each p suborbital can accommodate 2 electrons in opposite spin hence the capacity of p orbital is 6 electrons. These sub orbitals are degenerate (having an equal amount of energy). If the lobe of the orbital is sprayed along the x-axis, then that orbital is called px orbital. Similarly if the lobe is sprayed along y-axis then that orbital is called py orbital and if lobe is sprayed along z-axis then that orbital is called pz orbital. Box Diagram Fig. 1.6 : Dumbbell Shape of p-Orbitals d-Orbital There are five d- sub orbitals (dxy, dyz, dxz, dx2–y2 and dz2) orbitals [Fig. 1.7]. d-orbitals are having the double dumb-bell shape or four-lobe planar structure. These orbitals are directional and along the axis orbital (dx2–dy2 and dz2) as well as in between the axis orbitals (dxy, dyz and dxz). Each d sub orbital can accommodate 2 electrons in opposite spin hence the maximum capacity of d orbital to accommodate electrons is 10 electrons. dxy dyz dxz dx2–y2 dz2 In between the Along the axis orbitals axis orbitals Box Diagram Fig. 1.7 : Double Dumbbell Shape of d-Orbitals f-Orbital There are seven f- sub orbitals fx(x2-3y2), fy(3x2-y2),fz(x2-y2),fxz2, fyz2, fz3, fxyz  Atomic Structure,Chemical Bonding and Solutions | 9 f-orbitals are having a complicated shape. Each f-orbital are having seven f-sub orbitals hence capacity to accommodate electrons is 14 electrons. 1.1.7 Quantum Numbers The Bohr model was a one-dimensional model that used one quantum number to describe the distribution of electrons in the atom. It explains the size of the orbit, which was described by the principal quantum number (n). Schrodinger’s model allowed the electron to occupy three-dimensional space. It therefore required set of four quantum numbers, to describe the orbitals in which electrons can be found. Four quantum numbers as principal quantum number(n) give information about main energy level; azimuthal quantum number (l)provides information about sub energy level; magnetic quantum number (m) gives information of orientation of sub-energy level and spin quantum number (ms) gives the direction of spin. These four quantum numbers in an atom give the exact position of the electron, it is just like working of global positioning system (GPS) location or address, we can say that these quantum numbers give the exact location or address of electron. (A) Principal Quantum Number (n) This quantum number is represented by the letter (n). This number gives information on the position of the electron as well as the energy associated with the electron. The values of ‘n’ are positive integral numbers as 1, 2, 3, 4…etc. corresponding to K, L, M, N…etc. shells. (B) Angular Momentum Quantum Number or Azimuthal Quantum Number (l) This quantum number is represented by the letter (l). It is used to describe sub-energy level. Values of azimuthal quantum numbers are all possible whole numbers from 0 to n-1 When n=1 thus l=0 (Represents s-orbital) When n=2 thus l=0,1 (Represents s and p orbital) When n=3 thus l=0,1,2 (Represents s, p and d orbital) When n=4 thus l=0,1,2,3 (Represents s, p, d and f orbital) Thus various subshells are designated as s, p, d, f according to the value of l=0, 1, 2, 3 respectively. (C) Magnetic Quantum Number (m) This quantum number is represented by the letter (m). It is used to describe the orientation of the orbitals. The number of values allowed to m depends on the values of l. Possible values of m range from –l through 0 to +l thus making a total of 2l+1 values. table 1.2 10 | Applied Chemistry Table 1.2 : Magnetic Quantum Number Azimuthal Calculation of Values of Magnetic Orientation around Quantum Number (l) Magnetic Quantum Quantum Number the nucleus Number (m= 2l + 1) l=0 (s-orbital) m=2 x 0+1= 1 0 one l=1 (p-obital) m=2 x 1+1= 3 -1,0, +1 three l=2 (d-orbital) m=2 x 2+1= 5 -2, -1, 0, +1, +2 five l=3 (f-orbital) m=3 x 2+1= 7 -3, -2,-1,0,+1,+2,+3 seven (D) Spin Quantum Number (ms) This quantum number is represented by (ms). It shows the direction in which the electron is spinning about its own axis. The spin quantum number shows two possible values i.e. clockwise spin as + and anticlockwise spin as – 1.1.8 Pauli’s Exclusion Principle No two electrons in a single atom can have same set of four quantum numbers. In an atom two electrons can have a same set of three quantum numbers but they must differ in the value of fourth quantum number table 1.3 The first two electrons in [Ne] gas have the same set of three quantum numbers but differ in spin quantum number i.e. one with + spin and other with - spin. Table 1.3 : Four Quantum Numbers for First 10 Electrons in [Ne] Principal Azimuthal Quantum Magnetic Spin Remarks Quantum No. (l ) = 0 to n-1 Quantum Quantum No. (n) No. (m)=-l No. (ms) to + l 1 (K shell) 0 (s-sub energy level) 0 + First s electron in 1s 0 (s- sub energy level) 0 – Second s electron in 1s 2 (L shell) 0 (s- sub energy level) 0 + First s electron in 2s 0 (s- sub energy level) 0 – Second s electron in 2s  Atomic Structure,Chemical Bonding and Solutions | 11 1 (p- sub energy level) -1 + First p electron in 2px 1 (p- sub energy level) 0 + First p electron in 2py 1 (p- sub energy level) +1 + First p electron in 2pz 1 (p- sub energy level) -1 – Second p electron in 2px 1 (p- sub energy level) 0 – Second p electron in 2py 1 (p- sub energy level) +1 – Second p electron in 2pz 1.1.9 Hund’s Rule of Maximum Multiplicity When several orbitals with same energy are available, the electrons enters in all orbitals with parallel spin, before pairing in any one orbital. Electron pairing in any orbital is not possible until the available orbitals of the same energy from the given subshell contains one electron each. Electrons of different atoms while entering into p-orbital follows Hund’s rule as shown in table 1.4 Table 1.4 : Pairing Arrangement of Electrons Permitted by Hund’s Rule Description Orbital Permitted by Not Permitted by Hund’s Rule Hund’s Rule With one p electron e.g. B p px py pz With two p electrons e.g. C p px py pz px py pz With three p electrons e.g. N p px py pz px py pz With four p electrons e.g. O p px py pz px py pz With five p electrons e.g. F p px py pz 12 | Applied Chemistry With six p electrons e.g. Ne p px py pz 1.1.10 Aufbau Rule When several orbitals are available, electron enters into all available orbitals with an increasing amount of energy. i.e. orbitals with lower energy are filled first then electrons enters into higher energy orbitals. 1s