ENGINEERING CHEMISTRY - I For Students of First Semester B.E/B.Tech (Common to All Branches) As Per the Latest ANNA UNIVERSITY Syllabus (Regulation 2013) REVISED EDITION : 2014 2015 Dr. A. KULANDAISAMY, M.Sc., Ph.D., (Formerly Kalasalingam University) Assistant Professor, Dept. of Chemistry Raja Doraisingam Government Arts College, Sivagangai 630 561. S. SHANTHI, M.Sc., M.Phil., Ph.D., Assistant Professor, Department of Chemistry, Anand Institute of Higher Technology, Kalasalingam Nagar, Chennai - 603 103. No. 1A/15, O Block, Kumarasamy Nagar, Villivakkam, Chennai-600 049. Contact : 9080505073, 8122338899, 9994784517 srimaruthipub@gmail.com (i)
No part of this publication may be reproduced or distributed in any form or by means, electronic, mechanical, photocopying, recording, or otherwise stored in a database or retrieval system without the prior written permission of this publishers. Information contained in this work has been obtained by Sri Maruthi Publishers from sources believed to be reliable. However neither Sri Maruthi Publishers nor its authors guarantee the accuracy or completeness of any information published and they shall not be responsible for any errors arising out of this information. This publication aims to supply information but not to be understood as a professional service. Copyright 2013 by Sri Maruthi Publishers, Chennai. First Edition : July 2013 (Regulation : 2013) Revised Edition : June 2014 Printed in INDIA Engineering Chemistry - I Price : Rs. 360/- With FREE BOOKLET Published by : Sri Maruthi Publishers, Chennai Credits: Team Coordinator Laser Typesetting : R. Babu Rajendran, M. Sugumar, D. Prabu : Smart Designs & Prints Wrapper designed by : Sri Maruthi Publishers Printed by : Sri Maruthi Offset, Chennai. (ii) PREFACE Chemistry is indispensable part of the training of our budding engineers and scientists. This is because virtually all of today s technology is based on this enumulative knowledge. This book has been written to cater the needs of First Semester B.E./B.Tech. students according to the new syllabus (Regulation 2013) prescribed by the ANNA UNIVERSITY The book ENGINEERING CHEMISTRY-I comprises of five units which covers almost the entire syllabus. Topics like Polymer Chemistry, Chemical Thermodynamics, Photochemistry and Spectroscopy, Phase Rule and Alloys, Nanochemistry are explained in a simple and lucid manner. Most of these topics are customarily taught in engineering chemistry courses in several universities and institutes. An important feature of this book is the inclusion of Part-A Questions and Answers, Important Part-B Questions, Review Questions. Solved Anna University Question Papers upto 2014 in Free Booklet. Revised Edition : June 2014 (iii) AUTHORS REVISED EDITION : 2014-2015
ACKNOWLEDGEMENT First of all, I thank GOD ALMIGHTY for everything. We express our sincere gratitude to Philanthopist, Kalvivallal Thiru. T. Kalasalingam, Chairman, Seva Ratna Shri K. Shridharan, Secretary, Dr. S. Arivalagi, Director Anand Institute of Higher Technology, Chennai, for their support and encouragement. We extremely thankful to the principal Dr. T.A. Raghavendran for permitting us to write this Text Book. We would like to put on record our sincere gratitude to Dr. S. Chokkalingam, HOD Chemistry Department, Anand Institute of Higher Technology, Chennai for giving a valuable suggestion to write this Text Book. We thank our colleagues and friends for their inspirations. We deeply acknowledge our Family Members for their never ending encouragement, moral support and patience on all our endeavors. We wish to thank to Sri Maruthi Publishers for the sustained interest shown by them during the entire work. S. Shanthi (iv) (v)
SYLLABUS (Regulation 2013) CY6151 ENGINEERING CHEMISTRY - I L T P C 3 0 0 3 UNIT - I POLYMER CHEMISTRY 9 Introduction: Classification of polymers Natural and synthetic; Thermoplastic and Thermosetting. Functionality Degree of polymerization. Types and mechanism of polymerization: Addition (Free Radical, cationic and anionic); condensation and copolymerization. Properties of polymers: Tg, Tacticity, Molecular weight weight average, number average and polydispersity index. Techniques of polymerization: Bulk, emulsion, solution and suspension. Preparation, properties and uses of Nylon 6,6, and Epoxy resin. UNIT - II CHEMICAL THERMODYNAMICS 9 Terminology of thermodynamics : Second law: Entropy - entropy change for an ideal gas, reversible and irreversible processes; entropy of phase transitions; Clausius inequality. Free energy and work function: Helmholtz and Gibbs free energy functions (problems); Criteria of spontaneity; Gibbs- Helmholtz equation (problems); Clausius-Clapeyron equation; Maxwell relations Van t Hoff isotherm and isochore(problems). (vi) (vii)
UNIT - III PHOTOCHEMISTRY AND SPECTROSCOPY 9 Photochemistry: Laws of photochemistry - Grotthuss Draper law, Stark Einstein law and Lambert- Beer Law. Quantum efficiency determination- Photo processes - Internal Conversion, Inter-system crossing, Fluorescence, Phosphorescence, Chemiluminescence and Photo-sensitization. Spectroscopy: Electromagnetic spectrum - Absorption of radiation Electronic, Vibrational and rotational transitions. UV-visible and IR spectroscopy principles, instrumentation (Block diagram only). UNIT - IV PHASE RULE AND ALLOYS 9 Phase rule: Introduction, definition of terms with examples, One Component System- water system - Reduced phase rule - Two Component Systems- classification lead-silver system, zincmagnesium system. Alloys: Introduction- Definition- Properties of alloys- Significance of alloying, Functions and effect of alloying elements- Ferrous alloys- Nichrome and Stainless steel heat treatment of steel; Non-ferrous alloys brass and bronze. UNIT - V NANOCHEMISTRY 9 Basics - distinction between molecules, nanoparticles and bulk materials; size-dependent properties. nanoparticles: nano cluster, nano rod, nanotube (CNT) and nanowire. Synthesis: precipitation, thermolysis, hydrothermal, solvothermal, electrodeposition, chemical vapour deposition, laser ablation; Properties and applications. TOTAL : 45 PERIODS (viii) CONTENTS POLYMER CHEMISTRY 1 1.1 Introduction... 1.1 1.2 Classification of polymers... 1.3 1.2.1 Natural polymers... 1.3 1.2.2 Synthetic (or) Man-made polymers... 1.4 1.2.3 Classification of polymer on the basis of structure... 1.6 1.2.4 Classification of polymer based on application... 1.7 1.2.5 Plastics and their classifications... 1.10 1.3 Nomenclature of polymers... 1.13 1.4 Stereospecific Polymer (or) Tacticity... 1.14 1.5 Functionality and its Significance... 1.15 1.6 Degree of Polymerization... 1.17 1.7 Polymerization... 1.18 1.7.1 Types of Polymerization... 1.18 1.8 Mechanism of Addition Polymerization... 1.21 1.8.1 Free radical mechanism of Addition polymerization... 1.22 1.8.2 Ionic polymerization (or) Ionic mechanism... 1.24 1.8.3 Anionic mechanism of addition polymerization... 1.27 1.9 Coordination polymerization (or) Ziegler-Natta Polymerization... 1.30 1.10 Effect of polymer structure on properties (or) Properties of polymer... 1.34 (ix)
1.11 Glass transition temperature (T g )... 1.38 1.12 Molecular weight and molecular weight distribution... 1.40 1.12.1 Number average molecular weight (M n )... 1.41 1.12.2 Weight average molecular weight (M w)... 1.43 1.12.3 Polydispersity Index... 1.45 1.12.4 Viscosity average molecular weight (M v)... 1.45 1.13 Methods (or) Techniques of polymerization... 1.46 1.13.1 Bulk polymerization (or) Mass polymerization (or) Block polymerization... 1.46 1.13.2 Solution polymerization... 1.47 1.13.3 Suspension (or) Bead polymerization... 1.48 1.13.4 Emulsion polymerization... 1.49 1.14 Epoxy resins (or) Epoxide polymers... 1.50 1.15 Nylon 6:6... 1.51 Points to Remember... 1.53 Solved Problems... 1.57 Two Mark Questions & Answers... 1.59 Review Questions... 1.71 CHEMICAL THERMODYNAMICS 2 2.1 Introduction...2.1 2.1.1 Types of system...2.2 2.1.2 Homogeneous System...2.4 2.1.3 Properties of a system...2.4 2.1.4 Process and their types...2.5 (x) 2.1.5 Reversible Process (or) Thermodynamic reversibility...2.6 2.2 Enthalpy (or) Heat content of a system (H)...2.9 2.3 State of a system... 2.10 2.4 State variables or State function... 2.10 2.5 Laws of Thermodynamics... 2.11 2.5.1 Zeroth law of thermodynamics... 2.11 2.5.2 First Law of thermodynamics or Law of conservation of energy... 2.11 2.5.3 Heat capacity... 2.13 2.5.4 Limitations of First Law of thermodynamics. 2.13 2.5.5 Need for Second Law of thermodynamics... 2.14 2.6 Second law of thermodynamics... 2.14 2.6.1 Entropy... 2.15 2.6.2 Entropy change in an isothermal expansion of an ideal gas... 2.17 2.6.3 Sign of entropy change in a reaction... 2.19 2.6.4 Spontaneous process (or) Irreversible process... 2.19 2.6.5 Criteria of spontaneity... 2.19 2.6.6 Entropy of the universe... 2.20 2.6.7 Inequality of Clausius (or) Clausius theorem... 2.21 2.6.8 Entropy of phase transition... 2.23 2.7 Free energy (or) New thermodynamics functions... 2.24 2.7.1 Gibbs free energy (G) (or) Thermodynamic potential... 2.25 2.7.2 Helmholtz free energy (or) Helmholtz work function (A)... 2.26 2.7.3 Criteria for the spontaneous process (or) Gibbs free energy and spontaneity... 2.27 (xi)
2.7.4 Conditions for spontaneity (or) Spontaneity and relative values of ΔH and ΔS... 2.29 2.7.5 Gibbs-Helmholtz equation (or) Relationship between ΔG &ΔH... 2.31 2.7.6 Applications of Gibb s Helmholtz equation... 2.36 2.8 Thermodynamic relations (or) Maxwell relations... 2.38 2.9 Van t Hoff isotherm... 2.45 2.10 Van t Hoff equation (or) Van t Hoff isochore (or) Variation of equilibrium constant with temperature. 2.47 2.11 Clausius-Clapeyron equation... 2.51 Solved Problems... 2.55 Points to Remember... 2.84 Two Mark Questions & Answers... 2.87 Review Questions... 2.97 PHOTOCHEMISTRY AND SPECTROSCOPY 3 PHOTOCHEMISTRY 3.1 Introduction... 3.1 3.2 Laws of photochemistry... 3.3 3.2.1 Grotthus-Draper law... 3.3 3.2.2 Stark-Einstein law of Photochemical equivalence (or) Principle of Quantum of activation... 3.3 3.3 Quantum yield... 3.4 3.3.1 Deviations in Quantum yield (or) High/ low Quantum yield... 3.5 (xii) 3.3.2 Low Quantum yield (or) Reactions with 1.. 3.6 3.3.3 High quantum yield or Reaction with 1... 3.7 3.4 Consequences of absorption of light by atoms (or) Molecules... 3.9 3.5 Determination of Quantum yield... 3.10 3.6 Photophysical processes... 3.13 3.6.1 Mechanism and energy transfer in photophysical processes or Jablonski diagram 3.13 3.6.2 Fluorescence... 3.17 3.6.3 Phosphorescence... 3.20 3.6.4 Chemiluminescence... 3.23 3.6.5 Bioluminescence... 3.24 3.6.6 Thermoluminescence... 3.25 3.7 Photochemical process... 3.25 3.7.1 Photosensitization... 3.25 3.7.2 Quenching... 3.27 3.7.3 Mechanism of photosensitization & Quenching 3.27 3.8 Photosynthesis... 3.20 Solved Problems... 3.30 SPECTROSCOPY 3.9 Types of Spectroscopy... 3.48 3.9.1 Types of Spectrum... 3.49 3.9.2 Photophysical Law... 3.50 3.9.3 Lambert s Law... 3.51 3.9.4 Beer s Law (or) Beer-Lambert s Law... 3.52 3.9.5 Electromagnetic radiation... 3.55 (xiii)
3.9.6 Electromagnetic Spectrum... 3.57 3.9.7 Born-oppenheimer approximation... 3.58 3.10 Energy Level diagram... 3.59 3.11 Rotational Transition... 3.60 3.11.1 Selection Rule for Rotational Transition (or) Spectra... 3.61 3.12 Vibrational Transition... 3.61 3.12.1 Selection rules for Vibrational and Rotational Transition... 3.62 3.12.2 Vibration of polyatomic molecules... 3.62 3.13 Electronic transition... 3.64 3.14 UV-visible Spectroscopy... 3.65 3.14.1 Origin of UV-Visible absorption spectra... 3.66 3.14.2 Types of electrons involved in organic molecule... 3.69 3.14.3 Types of electronic transition... 3.69 3.14.4 Instrumentation... 3.72 3.14.5 Applications... 3.75 3.15 Infra-Red Spectroscopy... 3.80 3.15.1 Molecular vibration and origin of IR spectrum... 3.82 3.15.2 Instrumentation... 3.85 3.15.3 Applications of IR spectroscopy... 3.87 Solved Problems... 3.96 Points to Remember... 3.107 Two Mark Questions & Answers... 3.115 Review Questions...3.130 PHASE RULE AND ALLOYS 4 4.1 Introduction... 4.1 4.2 Phase Rule... 4.2 4.3 Important Terms... 4.2 4.4 Phase diagrams... 4.7 4.5 Application of phase rule to one component system 4.7 4.5.1 Water system... 4.7 4.6 Two component systems (or) Multicomponent systems... 4.11 4.6.1 Reduced (or) Condensed Phase Rule... 4.11 4.7 Experimental method of construction of a simple eutectic phase diagram... 4.14 4.7.1 Thermal analysis (or) Cooling curve... 4.14 4.8 Binary alloy system (or) The Simple eutectic system... 4.16 4.8.1 Lead Silver system... 4.17 4.9 Zinc-Magnesium Alloy System... 4.20 4.10 Differences among melting point, triple point and eutectic points of temperature and pressure... 4.25 4.11 Introduction of alloys... 4.27 4.12 Classification of alloys... 4.30 4.13 Heat Treatment of alloys (or) Steels... 4.31 4.13.1 Types of Heat Treatment of Alloys/Steels... 4.32 4.14 Important Ferrous Alloys... 4.35 (xiv) (xv)
4.15 Important Non-Ferrous Alloys... 4.39 Points to Remember... 4.42 Two Mark Questions & Answers... 4.51 Review Questions... 4.60 NANOCHEMISTRY 5 5.1 Introduction... 5.1 5.1.1 Where is nanoscale materials found?... 5.2 5.1.2 Nanomaterials and their properties... 5.2 5.1.3 Classification of nanomaterials... 5.3 5.2 Comparative studies of nanoparticles and bulk materials... 5.4 5.2.1 Importance of nanomaterials... 5.5 5.2.2 Distinguish between molecules, nanoparticles and bulk materials... 5.6 5.3 Size dependent properties of nanomaterials... 5.7 5.4 Different types of Nanomaterials... 5.9 5.4.1 Nanoparticles... 5.9 5.4.2 Application of Nanoparticles... 5.10 5.4.3 Nanoclusters... 5.10 5.4.4 Nanowire... 5.11 5.4.5 Nanorod... 5.13 5.4.6 Nanotube... 5.14 5.4.7 Carbon nanotubes (CNTs)... 5.14 5.5 Approaches to Nanoscale synthesis or Synthesis of nanomaterials... 5.21 5.6 Laser ablation method... 5.23 5.7 Chemical vapour deposition... 5.25 5.8 Electrodeposition... 5.26 5.9 Precipitation processes... 5.28 5.10 Thermolysis... 5.29 5.11 Solvothermal synthesis... 5.30 5.12 Hydrothermal process... 5.31 5.13 Properties of Nanomaterials... 5.31 5.13.1 Optical properties... 5.32 5.13.2 Electrical properties... 5.33 5.13.3 Mechanical properties... 5.33 5.13.4 Magnetic properties... 5.34 5.13.5 Thermal conductivity... 5.35 5.13.6 Melting points... 5.36 5.14 Application of nanomaterials... 5.36 Points to Remember... 5.40 Two Mark Questions & Answers... 5.44 Review Questions... 5.51 INDEX.. I.1- I.4 b b b b b (xvi) (xvii)