The second law of thermodynamics and statistical mechanics. Work and efficiency as motivation for the development of the second law, we examine two types of processes that. O satisfying the first law alone does not ensure that the process will take place. Ideal gas law and kinetic theory of gases chapter 20 entropy and the second law of thermodynamics now we to look at temperature, pressure, and internal energy in terms of the motion of molecules and atoms. Preserving the quality of energy is a major concern of engineers. Principles covered include the first law of thermodynamics, the second law of thermodynamics, gibbs free energy, statistical thermodynamics, reaction kinetics, and on hypotheses of the origin of life. This section includes extremely refined notes for every lecture given in the course. The efficiency of an irreversible heat engine is always less than the efficiency of a. Dec 04, 2017 the second law of thermodynamics states that the change in entropy of a natural process is always a positive. The total entropy change of the closed system is dssys and is the sum of changes inside the system, dsint, and entropy transferred to the system from its. Chemical thermodynamics the field of biological thermodynamics is focused on principles of chemical thermodynamics in biology and biochemistry. The fi rst law of thermodynamics, that energy is conserved, just ells us what can happen.
Formal definition of the entropy you must be aware of the second law of thermodynamics. The first law of thermodynamics university college dublin. Second law of thermodynamics the first law of thermodynamics is a statement of the principle of conservation of energy. Second law of thermodynamics florida state university. Introduction to thermodynamics conservation of energy first law of thermodynamics energy cannot be created or destroyed, only converted between different forms example. Physics ppt thermodynamics laws entropy second law of. Limitation of first law the first law of thermodynamic states that a certain energy flow takes place when a system undergoes a process or change of state is possible or not. Chapter 4 thermodynamics second law of thermodynamics.
Lecture notes thermodynamics of materials materials. Engineering thermodynamics ppt free ebook download as powerpoint presentation. Ppt second law of thermodynamics powerpoint presentation. A process can occur when and only when it satisfies both the first and the second laws of thermodynamics. Relate to the 1st law of thermodynamics thermal expansion cracking the nut. Contoh second law of thermodynamics free download as powerpoint presentation. The second law of thermodynamics when objects of different temperatures are brought into thermal contact, the spontaneous flow of heat that results is always from the high temperature object to the low temperature object. The second law of thermodynamics introduces the notion of entropy s, a measure of system disorder messiness u is the quantity of a systems energy, s is the quality of a systems energy. Physical processes in nature can proceed toward equilibrium spontaneously. To use the latter equation, identify the index i with. The second law also states that the changes in the entropy in the universe can never be negative. The second law is also used in determining the theoretical limits for the performance of commonly used engineering systems, such as heat engines and. Joules law leads to an important conclusion concerning the internal energy of an ideal gas.
Lecture 14 ideal gas law and terms of the motion of molecules. The 2nd law of thermodynamics heat can be completely converted into work in a single process but continuous conversion of heat in to work requires a cyclic process a heat engine all attempts to construct a heat engine that is 100% efficient. In any cyclic process the entropy will either increase or remain the same. For an ideal reversible process, the entropy change is equal to or greater than zero. Nicolas leonard sadi carnot was a french physicist, who is considered to be the father of thermodynamics, for he is responsible for the origins of the second law of thermodynamics, as well as various other concepts. Thermodynamics can be defined as the since of energy and entropy. The second law of thermodynamics states that the change in entropy of a natural process is always a positive.
More specifically, we take the term universe to mean the system and the surroundings. Second law of thermodynamics and can be stated as follows. Second law of thermodynamics heat of itself never flows from a cold object to a hot object. Apr 20, 2015 a self contained powerpoint to cover entropy and the second law of thermodynamics. Biological thermodynamics internal energy u is the energy within the system the internal energy of a system is the total kinetic energy due to the motion of molecules translational, rotational, vibrational and the total potential energy associated with the vibrational and electric energy of atoms within molecules or crystals. Why is it that when you leave an ice cube at room temperature, it begins to melt. The 2nd law of thermodynamics heat can be completely converted into work in a single process but continuous conversion of heat in to work requires a cyclic process a heat engine all attempts to construct a heat engine that is 100% efficient have failed the kelvin planck statement of the. Characterized by two principal laws first law a restatement of the law of conservation of energy as it applies to systems involving changes in temperature. The second law of thermodynamics is also used in determining the theoretical limits for the performance of commonly used engineering systems. In the rst law work and heat are treated on an equivalent basis. Presented by group 8th rully efriadimariatul kibtiah suryaman 2.
Chapter 4 thermodynamics second law of thermodynamics 2. The second law of thermodynamics 1 chapter 6 the second law of thermodynamics study guide in powerpoint to accompany thermodynamics an engineering approach, 7th edition by yunus a. The subject matter below is usually covered in introductory physical chemistry courses. To be able to use the first law of thermodynamics to estimate the potential for thermomechanical energy conversion in aerospace power and propulsion systems. The first, second, and third law of thermodynamics thlaws05. The carnot efficiency of such an engine is about e t c t h. Heat can flow spontaneously from a hot object to a cold object. Thermodynamics thermodynamics can be defined as the since of energy and entropy. It does work to turn the blades some heat changes into work and rest of the heat energy. If a gas neither does external work nor takes in or gives out heat, dq 0 and dw 0, so that, by the first law of thermodynamics, du 0.
Entropy and the second law of thermodynamics the second law of thermodynamics mech3400 2nd law other formulations kelvinplanck statement. Lecture 14 ideal gas law and terms of the motion of. Second law of thermodynamics the second law of thermodynamics. Second law of thermodynamics study gtusysllabus,gtu.
Why it is important to formulate the law for open systems can be illustrated with fig. Powerpoint presentation chapter 19 chemical thermodynamics. The increase of the internal energy of a system is equal to the sum of the heat added to the system plus the work done on the system. The third law and free energy introduction we have seen that the second law of thermodynamics does not enable the absolute value of entropy of any substance to be calculated. O establishing conditions for equilibrium, o provide means for predicting the direction of processes, o second law is useful. According to joules law, under these conditions the temperature of the gas does not change, which implies. The second law of thermodynamics universitetet i oslo. In reversible process, the thermodynamic process can be reversed. The second law of thermodynamics is a consequence of the theory of probability. The second law of thermodynamics states that the state of entropy of the entire universe, as an isolated system, will always increase over time. Boles 2 the second law of thermodynamics states that processes occur in a certain direction, not in just any direction. The second law of thermodynamics entropy entropy and the the second law of thermodynamics entropy entropy and the direction of time microscopically the eqs.
T k represent the temperatures of the subsystems at which the heat. The second law of thermodynamics is concerned with the maximum fraction of a quantity of heat that can be converted into work. A pure gas or vapour under compression or expansion is an example of a simple system. Wingdings times new roman symbol trebuchetmsbold arialms blank presentation. If two systems are separately found to be in thermal equilibrium with a third system, the first two systems are in thermal. Two conclusions are drawn which are known as the carnot principles, expressed as follows. The second law of thermodynamics can determine the preferred direction for the processes. The starting point for most thermodynamic considerations are the laws of thermodynamics, which postulate that energy can be exchanged between physical systems as heat or work. The second law of thermodynamics the first law of thermodynamics is simple, general, but does not constitute a. Physics ppt thermodynamics laws free download as powerpoint presentation. Heat engineapplication of second lawthermodynamic 3. Contoh second law of thermodynamics entropy second law.
The second law of thermodynamics states that processes occur in a certain direction, not in just any direction. The first, second, and third law of thermodynamics. The second law of thermodynamics is a statement about which processes occur and which do not. Method vibrational energy levels have a constant separation in the harmonic approx. The entropy of the world increases clausius 1850 thermodynamics paul and tatiana ehrenfest, the conceptual foundation of the statistical approach in mechanics, german edition, teubner, leipzig, 1912. Choosing a clever system is half the solution of many thermodynamical problems. Whenever heat is added to a system, it transforms into an equal amount of some other form of energy. Thermodynamics defined thermodynamics is the study of heat and its transformation to mechanical energy.
The entropy of the universe does not change for reversible processes and increases for spontaneous processes. Sep 30, 2019 major players in developing the second law. The second law of thermodynamics 1 the second law of thermodynamics 2 no transcript 3 no transcript 4. Thermodynamics in physics, thermodynamics is the study of energy conversion between heat and mechanical work, and subsequently the macroscopic variables such as temperature, volume and pressure. A gas can be heated to the temperature of the bottom of the pond, and allowed to cool as it blows through a turbine. The second law of thermodynamics 1 the second law of thermodynamics in any physical process, the entropy of the universe shall tend to increase. Heat engines, entropy, and the second law of thermodynamics. A self contained powerpoint to cover entropy and the second law of thermodynamics.
Engineering thermodynamics ppt second law of thermodynamics. Clausius statement clausius statement of second law of thermodynamic is as below it is impossible to construct a device as heat pump that. Examples of processes which are not prohibited by the first law, but cannot happen in a real world. For combined system and surroundings, entropy never decreases. Determine the expressions for the thermal efficiencies and coefficients of performance for reversible heat engines, heat pumps, and refrigerators. The second law of thermodynamics states that in all energy exchanges, if no energy enters or leaves the system, the potential energy of the state will always be less than that of the initial state. Part v third law 165 virginia commonwealth university. We will introduce the rst and second law for open systems.
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