Thermodynamics and Phase Rule Lecture PDF

Thermodynamics and Phase rule Dr. Emad Matter Thermodynamics and Phase rule  Heat, Energy and work,  The phase rule equation,  First law of thermodynamics,  One-component systems,  Heat capacities,  Two component systems ...

Thermodynamics and Phase rule Dr. Emad Matter Thermodynamics and Phase rule  Heat, Energy and work,  The phase rule equation,  First law of thermodynamics,  One-component systems,  Heat capacities,  Two component systems  Adiabatic processes, consisting of solid and liquid  Joule-Thomson effect, phases,  Thermochemistry,  Compound formation,  Second and third law of  Solid solutions, thermodynamics,  Three component systems.  Carnot cycle,  Entropy and free energy,  Properties of solutions.  Thermodynamics Some examples include the electric or gas range, the heating and air conditioning systems, the refrigerator, the water heater, the shower, the computer, and the TV. On a large scale, thermodynamics plays a major part in the design and analysis of automotive engines, rockets, jet engines, and conventional or nuclear power plants, solar collectors, and the design of vehicles from ordinary cars to airplanes.  Basic Concepts of Thermodynamics Thermodynamics Is the science of the relation between heat, work and the properties of the systems, and it enables us to adopt these interaction to our benefits In studying and evaluating the flow of energy into or out of a system it will be useful to consider changes in certain properties of the system (T, P, V and Conc.). Application of thermodynamics Derivation most of the important laws (Physical Chemistry, and phase ). Telling a particular physical or chemical change under a given set of conditions. Limitations Predicting how far a physical or chemical change can proceed of Thermodynamics until is applicable to macroscopic the equilibrium systems conditions areconsisting of matter and not to established. microscopic systems of individual atoms or molecules.  does not tell anything regarding the rate of a physical change or a chemical reaction. (time factor)  TERMS AND BASIC CONCEPTS 1. SYSTEM, BOUNDARY and SURROUNDINGS  TERMS AND BASIC CONCEPTS 2. Homogeneous and Heterogeneous systems A homogeneous A heterogeneous system is one system is one which which consists of consists of two or only one phase. more phases.  TERMS AND BASIC CONCEPTS 3. Types of thermodynamic systems dm = dm ‡ dm = 0 0 0 dE ‡ 0 dE = 0 dE ‡ 0  TERMS AND BASIC CONCEPTS 3. Types of thermodynamic systems What are adiabatic systems? Those systems, in which no thermal energy passes into or out of the system. dq = 0  TERMS AND BASIC CONCEPTS 4. Intensive and extensive properties Intensive Extensive A property which A property that does not depend on depend on the the quantity of matter quantity of matter present in the system present in the system  5. STATE OF A SYSTEM The fundamental properties which determine the state of a system are pressure (P), temperature (T), volume (V), mass and composition. These properties depends only on the initial state and final state of the system. Equation of State for one mole of a pure gas, is PV = RT. If we heat a sample of water from 0°C to 25°C, the change in temperature is equal to difference between the initial and final temperatures.  6. Equilibrium and Non-equilibrium states -A system in which the state variables have constant values throughout the system, is said to be in a state of thermodynamic equilibrium. -A system in which the state variables have different values in different parts of the system, is said to be in a non-equilibrium state.  The criteria for Equilibrium: The temperature of the system must be uniform and same as the temperature of the surroundings. (Thermal equilibrium). The mechanical properties must be uniform through the system (Mechanical equilibrium). (no mechanical work is done by one part of the system on any other part of the system. The chemical composition of the system must be uniform, with no net chemical change (chemical equilibrium).  7. Types of thermodynamic processes When a thermodynamic system change from one state to another, the operation is called a process, that involve the change of conditions (temperature, pressure and volume). (1)Isothermal process. in which the temperature remains fixed,  This is often achieved by placing the system in a thermostat.  For an isothermal process dT = 0 (2) Adiabatic Process. in which no heat can flow into or out of the system. Adiabatic conditions can be approached by carrying the process in an insulated container such as thermos bottle. For an adiabatic process dq = 0 (3) Isobaric process. which take place at constant pressure.  For example, heating of water to its boiling point, and its vaporisation take place at the same atmospheric pressure.  For all isobaric processes dp = 0. (4) Isochoric processes. in which the volume remains constant.  The heating of a substance in a non-expanding chamber is an example of isochoric process.  For isochoric process dV = 0. (5) Cyclic processes When a system in a given state goes through a number of different processes and finally returns to its initial state, the overall process is called a Cycle process.  For a cyclic process dE = 0, dH= 0.  8. Reversible and irreversible process. A thermodynamic reverse process is one that takes place infinitesimally slowly and its direction at any point can be reversed by an infinitesimal change in the state of the system. When a process goes from the initial to the final state in a single step and cannot be carried in the reverse order, it is said to be an irreversible process.  NATURE OF HEAT AND WORK When a change in the state of a system occurs, energy is transferred to or from the surroundings. This energy may be transferred as heat or mechanical work. Units of work In CGS system: The erg unit, to the joule (J) :. 1 joule =107 ergs 1 erg = 10-7 J 1 KJ = 1000J  Units of Heat. The unit of heat is calorie (cal). A calorie is defined as that quantity of heat required, to raise the temperature of one gram of water by l °C in Since the vicinity heat andof 15 are work °C.interrelated, SI unit of heat is the joule (J). 1 Joule = 0.2390 calories 1 Calorie = 4.184 J 1 Kcal = 4.184 KJ  Sign Convention of Heat. The symbol of heat is q. If the heat flows from the surroundings into the system to raise the energy of the system; it is taken to be positive, +q. If heat flows from the system into the surroundings, lowering the energy of the system, it is taken to be negative, -q. Sign Convention of work. The symbol of work is w. If work is done on a system by the surroundings and the energy of the system is thus increased, it is taken to be positive, +w. If work is done by the system on the surroundings and energy of the system is decreased, it is taken to be negative, -w.  Summary of Sign Conventions Heat flows into the system, q is + Work is done on the system, w is + Heat flows out of the system, q is – Work is done by the system, w is-  1. SYSTEM, BOUNDARY and SURROUNDINGS 2. Homogeneous and Heterogeneous systems 3. Types of thermodynamic systems 4. Intensive and extensive properties 5. STATE OF A SYSTEM 6. Equilibrium and Non-equilibrium states 7. Types of thermodynamic processes 8. Reversible and irreversible process. NATURE OF HEAT AND WORK Thank you for your