  in thermodynamics, a reversible process -- or reversible cycle if the process is cyclic -- is a process that can be "reversed" by means of infinitesimal changes in some property of the system without entropy production (i.e. dissipation of energy).sears, f.w. and salinger, g.l. (1986), thermodynamics, kinetic theory, and statistical thermodynamics, 3rd edition (addison-wesley.) due to these infinitesimal changes, the system is in thermodynamic equilibrium throughout the entire process. 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, the system and its surroundings will be exactly the same after each cycle.zumdahl, steven s. (2005) "10.2 the isothermal expansion and compression of an ideal gas." chemical principles. 5th edition. (houghton mifflin company) in thermodynamics, processes can be carried out in one of two ways: reversibly or irreversibly. reversibility in thermodynamics refers to performing a reaction continuously at equilibrium. in an ideal thermodynamically reversible process, the energy from work performed by or on the system would be maximized, and that from heat would be minimized; heat cannot fully be converted to work and will always be lost to some degree (to the surroundings). the phenomenon of maximized work and minimized heat can be visualized on a pressure-volume curve, as the area beneath the equilibrium curve, representing work done. in order to maximize work, one must follow the equilibrium curve closely. irreversible processes, on the other hand, are a result of straying away from the curve, therefore decreasing the amount of overall work done; an irreversible process can be described as a thermodynamic process that leaves equilibrium. when described in terms of pressure and volume, it occurs when the pressure or the volume of a system changes so dramatically and instantaneously that the other (pressure or volume in this case) does not have time to catch up. a classic example of irreversibility is allowing a certain volume of gas to be released into a vacuum. by releasing pressure on a sample and thus allowing it to occupy a large space, the system and surroundings will have completely left equilibrium, and heat dissipation will be large compared to the little work done. lower, s. (2003) entropy rules! what is entropy? entropy an alternative definition of a reversible process is a process that, after it has taken place, can be reversed and causes no change in either the system or its surroundings. in thermodyn
Thermodynamic_processes