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Specific Heat Capacity Heat Heat capacity or thermal capacity is a measurable physical quantity equal to the ratio of the heat added to (or removed from) an object to the resulting temperature change.[1] The unit of heat capacity is joule per kelvin J K displaystyle mathrm tfrac J K , or kilogram metre squared per kelvin second squared k g ⋅ m 2 K ⋅ s 2 displaystyle mathrm tfrac kgcdot m^ 2 Kcdot s^ 2 in the International System of Units International System of Units (SI). The dimensional form is L2MT−2Θ−1 [...More...] 


Carnot Heat Engine A Carnot heat engine[2] is a theoretical engine that operates on the reversible Carnot cycle. The basic model for this engine was developed by Nicolas Léonard Sadi Carnot Nicolas Léonard Sadi Carnot in 1824. The Carnot engine model was graphically expanded upon by Benoît Paul Émile Clapeyron in 1834 and mathematically explored by Rudolf Clausius Rudolf Clausius in 1857 from which the concept of entropy emerged. Every thermodynamic system exists in a particular state. A thermodynamic cycle occurs when a system is taken through a series of different states, and finally returned to its initial state. In the process of going through this cycle, the system may perform work on its surroundings, thereby acting as a heat engine. A heat engine acts by transferring energy from a warm region to a cool region of space and, in the process, converting some of that energy to mechanical work. The cycle may also be reversed [...More...] 


Statistical Mechanics Statistical mechanics Statistical mechanics is a branch of theoretical physics that uses probability theory to study the average behaviour of a mechanical system whose exact state is uncertain.[1][2][3][note 1] Statistical mechanics Statistical mechanics is commonly used to explain the thermodynamic behaviour of large systems. This branch of statistical mechanics, which treats and extends classical thermodynamics, is known as statistical thermodynamics or equilibrium statistical mechanics. Microscopic mechanical laws do not contain concepts such as temperature, heat, or entropy; however, statistical mechanics shows how these concepts arise from the natural uncertainty about the state of a system when that system is prepared in practice [...More...] 


Chemical Thermodynamics Chemical thermodynamics Chemical thermodynamics is the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the confines of the laws of thermodynamics. Chemical thermodynamics involves not only laboratory measurements of various thermodynamic properties, but also the application of mathematical methods to the study of chemical questions and the spontaneity of processes. The structure of chemical thermodynamics is based on the first two laws of thermodynamics. Starting from the first and second laws of thermodynamics, four equations called the "fundamental equations of Gibbs" can be derived. From these four, a multitude of equations, relating the thermodynamic properties of the thermodynamic system can be derived using relatively simple mathematics [...More...] 


Quantum Thermodynamics Quantum thermodynamics is the study of the relations between two independent physical theories: thermodynamics and quantum mechanics. The two independent theories address the physical phenomena of light and matter. In 1905 Einstein Einstein argued that the requirement of consistency between thermodynamics and electromagnetism[1] leads to the conclusion that light is quantized obtaining the relation E = h ν displaystyle E=hnu . This paper is the dawn of quantum theory. In a few decades quantum theory became established with an independent set of rules.[2] Currently quantum thermodynamics addresses the emergence of thermodynamic laws from quantum mechanics. It differs from quantum statistical mechanics in the emphasis on dynamical processes out of equilibrium [...More...] 


Heat In thermodynamics, heat refers to energy that is transferred from a warmer substance or object to a cooler one [...More...] 


State Of Matter In physics, a state of matter is one of the distinct forms in which matter can exist. Four states of matter are observable in everyday life: solid, liquid, gas, and plasma. Many other states are known to exist, such as glass or liquid crystal, and some only exist under extreme conditions, such as Bose–Einstein condensates, neutrondegenerate matter, and quarkgluon plasma, which only occur, respectively, in situations of extreme cold, extreme density, and extremely highenergy. Some other states are believed to be possible but remain theoretical for now. For a complete list of all exotic states of matter, see the list of states of matter. Historically, the distinction is made based on qualitative differences in properties. Matter Matter in the solid state maintains a fixed volume and shape, with component particles (atoms, molecules or ions) close together and fixed into place [...More...] 


Heat Engine In thermodynamics, a heat engine is a system that converts heat or thermal energy—and chemical energy—to mechanical energy, which can then be used to do mechanical work.[1][2] It does this by bringing a working substance from a higher state temperature to a lower state temperature. A heat source generates thermal energy that brings the working substance to the high temperature state. The working substance generates work in the working body of the engine while transferring heat to the colder sink until it reaches a low temperature state. During this process some of the thermal energy is converted into work by exploiting the properties of the working substance. The working substance can be any system with a nonzero heat capacity, but it usually is a gas or liquid. During this process, a lot of heat is lost to the surroundings and so cannot be converted to work. In general an engine converts energy to mechanical work [...More...] 


Quasistatic Process In thermodynamics, a quasistatic process is a thermodynamic process that happens slowly enough for the system to remain in internal equilibrium. An example of this is quasistatic compression, where the volume of a system changes at a rate slow enough to allow the pressure to remain uniform and constant throughout the system.[1] Any reversible process is necessarily a quasistatic one. However, quasistatic processes involving entropy production are irreversible. An example of a quasistatic process that is not reversible is a compression against a system with a piston subject to friction—although the system is always in thermal equilibrium, the friction ensures the generation of dissipative entropy, which directly goes against the definition of reversible [...More...] 


Polytropic Process A polytropic process is a thermodynamic process that obeys the relation: p V n = C displaystyle pV^ ,n =C where p is the pressure, V is volume, n is the polytropic index , and C is a constant [...More...] 


Free Expansion Free expansion Free expansion is an irreversible process in which a gas expands into an insulated evacuated chamber. It is also called Joule expansion. Real gases experience a temperature change during free expansion. For an ideal gas, the temperature doesn't change, and the conditions before and after adiabatic free expansion satisfy ( P i ) ( V i ) = ( P f ) ( V f ) displaystyle (P_ i )(V_ i )=(P_ f )(V_ f ) , where p is the pressure, V is the volume, and i and f refer to the initial and final states. Since the gas expands, Vf > Vi , which implies that the pressure does drop (Pf < Pi). During free expansion, no work is done by the gas [...More...] 


Reversible Process (thermodynamics) In thermodynamics, a reversible process is a process whose direction can be "reversed" by inducing infinitesimal changes to some property of the system via its surroundings, with no increase in entropy.[1] Throughout the entire reversible process, the system is in thermodynamic equilibrium with its surroundings. Since it would take an infinite amount of time for the reversible process to finish, perfectly reversible processes are impossible. However, if the system undergoing the changes responds much faster than the applied change, the deviation from reversibility may be negligible. In a reversible cycle, a cyclical reversible process, the system and its surroundings will be returned to their original states if one half cycle is followed by the other half cycle.[2] Thermodynamic processes can be carried out in one of two ways: reversibly or irreversibly. Reversibility means the reaction operates continuously at equilibrium [...More...] 


Irreversible Process In science, a process that is not reversible is called irreversible. This concept arises frequently in thermodynamics. In thermodynamics, a change in the thermodynamic state of a system and all of its surroundings cannot be precisely restored to its initial state by infinitesimal changes in some property of the system without expenditure of energy. A system that undergoes an irreversible process may still be capable of returning to its initial state. However, the impossibility occurs in restoring the environment to its own initial conditions. An irreversible process increases the entropy of the universe. Because entropy is a state function, the change in entropy of the system is the same, whether the process is reversible or irreversible [...More...] 


Endoreversible Thermodynamics Endoreversible thermodynamics Endoreversible thermodynamics is a subset of irreversible thermodynamics aimed at making more realistic assumptions about heat transfer than are typically made in reversible thermodynamics [...More...] 


Thermodynamic Cycle A thermodynamic cycle consists of a linked sequence of thermodynamic processes that involve transfer of heat and work into and out of the system, while varying pressure, temperature, and other state variables within the system, and that eventually returns the system to its initial state.[1] In the process of passing through a cycle, the working fluid (system) may convert heat from a warm source into useful work, and dispose of the remaining heat to a cold sink, thereby acting as a heat engine. Conversely, the cycle may be reversed and use work to move heat from a cold source and transfer it to a warm sink thereby acting as a heat pump. At every point in the cycle, the system is in thermodynamic equilibrium, so the cycle is reversible (its entropy change is zero, as entropy is a state function). During a closed cycle, the system returns to its original thermodynamic state of temperature and pressure. Process quantities (or path quantities), such as heat and work are process dependent [...More...] 


Thermodynamics Thermodynamics Thermodynamics is a branch of physics concerned with heat and temperature and their relation to other forms of energy and work. The behavior of these quantities is governed by the four laws of thermodynamics, irrespective of the composition or specific properties of the material or system in question. The laws of thermodynamics are explained in terms of microscopic constituents by statistical mechanics [...More...] 
