CHEM 240 Who am I? Thermodynamic studies Course for Engineering Students Dr. Mohamed Abdel Salam Assistant Professor of Physical Chemistry King Abdul Aziz University Jeddah KSA PhD in Nano Chemistry, Canada (2007) M Sc in Electrochemistry, Canada (2003) PhD in Physical Chemistry, Egypt (2001) M Sc in Physical Chemistry, Egypt (1994) 2 How to reach me Faculty of Science Chemistry Department, Room 411. Email me at: masalam16@hotmail.com masalam16@yahoo.com Leave a message at mail box Chemistry Department third floor www.kau.edu.sa/mabdelsalam 3 4 Grading System Text Book Any Physical Chemistry Book Selected textbook: Physical Chemistry R.A.Alberty and R.J.Silby. Physical Chemistry G.Barrow. 5 Lab work 25% Quizzes 10% Attendance & participation 10% Midterm exam 15% Final Exam 40%
Grading System 95 100 % A+ 90 95 % A 85 89 % B+ 80 84 % B 75 79 % C+ 70 74 % C 65 69 % D+ 60 64 % D < 60 % F (Fail) Chemistry 240 Syllabus Topic Numb Period Title Whats is due? er 1 3 Day week no.1 Introduction Kinetic theory of the gases important equations deduced from the theory 2 3 Day week no.2 Van der Waals eq. and the critical states the real state eq. the chain rule. 3 3 Day week no.3 Work and heat in physical chemistry Joules experiment the first law of thermodynamic solve some problems 4 3 Day week no.4 cyclic integral cyclic process exact and inexact functions solve problems 5 3 Day week no.5 work of compression and expansion change in state at constant volume and pressure periodic Exam. 1 6 3 Day week no.6 Heat capacities adiabatic process Carnote cycle heat engine solve some problems 7 3 Day week no.7 Kelvin and Clauses theories Entropy and the second low of thermodynamic change in entropy 8 3 Day week no.8 Entropy change in rev. process Combined first and second low Mid-term exam. 9 3 Day week no.9 Entropy change in irrev. process and entropy mixing third law of thermodynamic entropy for chemical reaction solve some problems 10 3 Day week no.10 Thermodynamic derivatives for closed systems Maxwells relations Effect of temperature and pressure on free energy. 11 3 Day week no.11 Fugacity and free energy Fundamental equations for open system Partial molar quantity solve some problems 12 3 Day week no.12 Phase equlibria water system and binary solutions second peiodic exam. 13 3 Day week no.13 Miscible and immiscible binary mixtures Intoduction for electrochemistry Electrochemical cells and EMF measurements thermodynamic relations for elect 14 3 Day week no.14 Activity activity coefficient ionic strength Debey-Hukel law Electrode potential chemical kinetics (first second and third order reactions). 8 15 2 Day week no.15 Final Examination 2 Hour What s in a name? Thermodynamics thermo = heat dynamics = power (mechanics) Study of the relation between heat and mechanics Yes 9 10 11 12
13 Introduction Physical chemistry establishes and develops: principles of chemistry concepts used to explain and interpret observations on the physical and chemical properties of matter Central theme: systems states Processes Topics of physical chemistry: othe study of the macroscopic properties of systems of many atoms or molecules othe study of processes which such systems can undergo othe study of the properties of individual atoms and molecules othe study of the relationship between microscopic (atomic or molecular) properties and macroscopic properties Main areas of physical chemistry Thermodynamics Quantum mechanics Statistical mechanics Kinetics and transport Example of a thermodynamic system: water, pure H 2 O, say 1 L at ambient pressure (1 atm) ice (solid) water (liquid) vapor (gas) 0 o C 100 o C What is the processes? Heating up the system; sharp transition from solid ice to water at 0 o C and from liquid water to water vapor at 100 o C. The macroscopic properties changes, but there is no change in the molecules or the forces between atoms. 15 16 Can we understand these changes? Can we predict the transition temperature, i.e., the melting temperature Tm and the boiling temperature Tb, or the macroscopic properties of the different phases, e.g., the molar volumes, or the dependence of the transition temperatures on pressure on impurities (e.g. salt), etc. Can two or more different phases exist for the same external conditions? carbon: 1) diamond: transparent, colorless, hard; 2) graphite: black, slippery, soft; 3) buckminsterfullerene: Process Processes (transformations, reactions): melting ice, evaporating water, burning methane,.. 17 18
Process 1) Can it occur? 2) Will it occur spontaneously? 3) How fast will it occur? thermodynamics: 1) and 2); kinetics: 3) How can we influence a process? applications: reactor design, catalysts, corrosion,... 19 Thermodynamics is the branch of science that predicts whether a state of some macroscopic system will remain unchanged or will spontaneously evolve to a new state. Kinetics is the branch of science that deals with how long it takes for a system to reach that new state. Mechanics is the branch of science that deals with the motions of small numbers of particles. Thermodynamics Applications of Thermodynamics Describes macroscopic properties of equilibrium systems Entirely Empirical Built on 4 Laws and simple mathematics 0 th Law Defines Temperature (T) 1 st Law Defines Energy (U) and its conservation 2 nd Law Defines Entropy (S) 3 rd Law Gives Numerical Value to Entropy 21 22 Definitions Kinds of Systems Surroundings System System: The part of the Universe that we choose to study Surroundings: The rest of the Universe Boundary: The surface dividing the System from the Surroundings Open system: exchange of energy and matter Closed system: exchange of energy but not matter Isolated system: can exchange neither energy nor matter 23 24
Describing systems requires A few macroscopic properties: p, T, V, n, m, Knowledge if System is Homogeneous or Heterogeneous Knowledge if System is in Equilibrium State Knowledge of the number of components 25 Two classes of Properties Extensive: Depend on the size of the system and will be double if the system is duplicated and added to itself (n,m,v, ) Intensive: Independent of the size of the system (T,p,ρ, molar volume ) 26 Thermal equilibrium If two closed system with fixed volumes are brought together (thermal contact), what will happened? The Zero th Law of Thermodynamic It is concerned with thermal equilibrium between three bodies, A, B and C. Changes may take place in the properties of both and finally a state is reached in which there is no further change, i.e. reach equilibrium and both system will have the 27 same final temperature. Consequences of the Zero th law: 28 If the volume of one of these systems is held constant, its pressure my vary over a range of values. If the pressure of one of these systems is held constant, its volume my vary over a range of values. Thus, V and P are independent thermodynamic variables. When one of the systems reach equilibrium at a certain P and V, all its macroscopic properties have certain characteristic values. 29