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Food Engineering Handbook Food Engineering Fundamentals Varzakas Theodoros, Tzia Constantina

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Food Engineering Handbook Food Engineering Fundamentals Varzakas Theodoros, Tzia Constantina This article was downloaded by: 10.3.98.104 On: 27 Sep 2021 Access details: subscription number Publisher: CRC Press Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: 5 Howick Place, London SW1P 1WG, UK Food Engineering Handbook Food Engineering Fundamentals Varzakas Theodoros, Tzia Constantina Fundamental Notes on Chemical Thermodynamics Publication details https://www.routledgehandbooks.com/doi/10.1201/b17843-4 Tzias Petros Published online on: 02 Dec 2014 How to cite :- Tzias Petros. 02 Dec 2014, Fundamental Notes on Chemical Thermodynamics from: Food Engineering Handbook, Food Engineering Fundamentals CRC Press Accessed on: 27 Sep 2021 https://www.routledgehandbooks.com/doi/10.1201/b17843-4 PLEASE SCROLL DOWN FOR DOCUMENT Full terms and conditions of use: https://www.routledgehandbooks.com/legal-notices/terms This Document PDF may be used for research, teaching and private study purposes. Any substantial or systematic reproductions, re-distribution, re-selling, loan or sub-licensing, systematic supply or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The publisher shall not be liable for an loss, actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material. Fundamental Notes 3 on Chemical Thermodynamics Petros Tzias CONTENTS 3.1 Introduction ....................................................................................................42 3.2 Scope ...............................................................................................................42 3.3 Glossary of Basic Thermodynamic Terms ..................................................... 43 3.3.1 System .................................................................................................44 3.3.2 Extensive and Intensive Properties .....................................................45 3.3.3 Phase ...................................................................................................45 3.3.4 Process ................................................................................................45 3.3.5 Molar Quantities .................................................................................45 3.3.6 Mole Fraction ......................................................................................46 3.3.7 Molality...............................................................................................46 3.4 Concepts of W, PE, KE, U, Q, and S ..............................................................46 3.5 Thermodynamic Laws .................................................................................... 47 3.5.1 First Law of Thermodynamics ...........................................................48 3.5.2 Second Law of Thermodynamics .......................................................48 3.5.3 Third Law of Thermodynamics..........................................................48 3.5.4 Law of Thermal Equilibrium ..............................................................48 3.6 Thermodynamic Functions and Some Relations for One-Phase Closed System .................................................................................................48 3.7 Fundamental Inequalities ...............................................................................50 3.8 Relations of Thermodynamic Functions in One-Phase Open System ........... 51 3.9 Mixtures ..........................................................................................................54 3.9.1 Mixing Functions ................................................................................54 3.9.2 Excess Functions ................................................................................ 55 3.9.3 Standard and Reference States of Thermodynamic Functions .......... 55 3.9.4 Dilution Thermodynamic Functions .................................................. 55 3.10 Gases and Gaseous Mixtures .........................................................................56 3.10.1 Fugacity ..............................................................................................57 3.10.2 The Standard State of a Gas Component ............................................58 3.11 Liquid Mixtures ..............................................................................................58 3.12 Equilibrium of Phases.....................................................................................60 41 Downloaded By: 10.3.98.104 At: 21:50 27 Sep 2021; For: 9781482261707, chapter3, 10.1201/b17843-4 42 Food Engineering Handbook 3.12.1 Phase Rule ..........................................................................................60 3.12.2 Chemical Potential in Phase Equilibria .............................................. 61 3.12.3 Binary Vapor–Liquid Systems ............................................................62 3.12.4 Principle of Corresponding States ......................................................64 3.12.5 Enthalpy and Entropy Change in a Two-Phase Transition .................65 3.13 Solutions .........................................................................................................66 3.14 Electrolyte Solution ........................................................................................68 3.14.1 Debye–Hückel Limiting Law .............................................................69 3.15 Thermochemistry: Chemical Reaction Equilibrium ......................................70 3.15.1 Enthalpy of Formation and Enthalpy of Reaction ..............................70 3.15.2 Determination of the Enthalpy of Reaction ........................................ 71 3.15.3 Equilibrium Constant: Affinity of a Reaction ....................................72 References ................................................................................................................73 3.1 INTRODUCTION Thermodynamics is a very useful tool for scientists and engineers such as chemists, geologists, geophysicists, mechanical and chemical engineers, and so on. Especially for chemists and chemical engineers with mathematics they form the cornerstone for their sciences. It is very useful when we study a handbook comprising chapters from a certain field of chemical engineering to have some handy notes of thermodynamics because this way we are released from the need at any time to seek and open other textbooks for better understanding of what we read. This is exactly the intention of this chapter. To provide a brief, elementary review of thermodynamics, reminding the reader of the basic laws, glossary, concepts, and relations of this important branch of science so as to make the study of the current volume much easier and pleasant. This chapter is addressed, as the content of the whole volume, to chemical engi- neers or chemists, and for this reason after presenting a few clauses of general inter- est we will next proceed to clauses dealing with chemical thermodynamics that is with mixtures, solutions, phase equilibriums, chemical reactions, and so on. Simple definitions of the different thermodynamic functions and quantities have been cited, and we will not enter to any analytical description or philosophical dis- cussion about them. Similarly, we will not prove the mentioned thermodynamic rela- tions, as these are beyond the scope of this chapter. We will deal only with reversible processes, so far as an interest is in chemi- cal thermodynamics, and we will not refer to statistical, as nuclear and relativistic phenomena. 3.2 SCOPE Thermodynamics is a branch of physical sciences concerned with the study of the transformation of heat, work, and other kinds of energy (electrical, light energy, etc.) from one form to another, in the different physicochemical phenomena and deter- mines the laws and relations governing and describing these energy transformations. Downloaded By: 10.3.98.104 At: 21:50 27 Sep 2021; For: 9781482261707, chapter3, 10.1201/b17843-4 Fundamental Notes on Chemical Thermodynamics 43 Historically [1] many scientists have studied the interconversion of heat and work, from N.L.S. Carnot with his famous ideal gas cycle, to Clausius who laid the founda- tion of the classical thermodynamics with the expression of the first and second law of thermodynamics. Later, J. Willard Gibbs extended the application of the thermodynamic postulates and relations to chemical reactions and phase equilibriums laying the foundation for the development of the field, which we today call chemical thermodynamics. Thermodynamics consists of a collection of equalities and inequalities which interrelate physical and chemical properties of substances as well as some physi- cal or chemical phenomena. These relations are deduced in a mathematical way from some laws, the thermodynamic laws, which are derived directly from experi- ence. The physical quantities used are taken either by physics or they are introduced in thermodynamics. Using these relations we can predict the possible direction of chemical reactions or the final result of a physical process. Thermodynamics is an experimental science [2]. All the physical or chemical quantities used in its relations are independently measurable, but some of them are easier to be measured than others. One very important use of thermodynamics is the possibility to calculate,
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