Search results
Results From The WOW.Com Content Network
A closed system is a natural physical system that does not allow transfer of matter in or out of the system, although – in the contexts of physics, chemistry, engineering, etc. – the transfer of energy (e.g. as work or heat) is allowed.
The sum of the last terms in the equations presents the total energy coming into the system with the stream of particles of substances that can be positive or negative; the quantity is chemical potential of substance .The middle terms in equations (2) and (3) depict energy dissipation (entropy production) due to the relaxation of internal ...
In this sense a system in chemical equilibrium is in a stable state. The system at chemical equilibrium will be at a constant temperature, pressure or volume and a composition. It will be insulated from exchange of heat with the surroundings, that is, it is a closed system. A change of temperature, pressure (or volume) constitutes an external ...
For example, if equilibrium is specified by a single chemical equation:, [24] ∑ j = 0 m ν j R j = 0 {\displaystyle \sum _{j=0}^{m}\nu _{j}R_{j}=0} where ν j is the stoichiometric coefficient for the j th molecule (negative for reactants, positive for products) and R j is the symbol for the j th molecule, a properly balanced equation will obey:
One such potential is the Helmholtz free energy (A), for a closed system at constant volume and temperature (controlled by a heat bath): = Another potential, the Gibbs free energy (G), is minimized at thermodynamic equilibrium in a closed system at constant temperature and pressure, both controlled by the surroundings:
This is one form of the Gibbs fundamental equation. [10] In the infinitesimal expression, the term involving the chemical potential accounts for changes in Gibbs free energy resulting from an influx or outflux of particles. In other words, it holds for an open system or for a closed, chemically reacting system where the N i are changing. For a ...
It is a particular example of a system in a steady state. In physics, concerning thermodynamics, a closed system is in thermodynamic equilibrium when reactions occur at such rates that the composition of the mixture does not change with time. Reactions do in fact occur, sometimes vigorously, but to such an extent that changes in composition ...
The entropy of a closed system, determined relative to this zero point, is then the absolute entropy of that system. Mathematically, the absolute entropy of any system at zero temperature is the natural log of the number of ground states times the Boltzmann constant k B = 1.38 × 10 −23 J K −1.