thermodynamics Thermodynamics is a branch of physics that deals with heat, Work (thermodynamics), work, and temperature, and their relation to energy, entropy, and the physical properties of matter and radiation. The behavior of these quantities is governed b ...

, the binodal, also known as the coexistence curve or binodal curve, denotes the state of a multi-component system at which the system's distinct phases straddle between coexistence or miscibility. Equivalently, it is the boundary on which thermodynamics favors the system components to dissolve or separate into two phases.IUPAC binodal curve definition http://old.iupac.org/goldbook/BT07273.pdf accessed 2/20/13 In general, the binodal is defined by the condition at which the

chemical potential In thermodynamics, the chemical potential of a Chemical specie, species is the energy that can be absorbed or released due to a change of the particle number of the given species, e.g. in a chemical reaction or phase transition. The chemical potent ...

of all solution components is equal in each phase. The extremum of a binodal curve in

temperature Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...

coincides with the extremum of the

spinodal In thermodynamics, the limit of local stability against phase separation with respect to small fluctuations is clearly defined by the condition that the second derivative of Gibbs free energy is zero. : 0 The locus of these points (the inflecti ...

curve, and is known as a critical point.

Binary systems

In binary (two component) mixtures, the binodal can be determined at a given temperature by drawing a tangent line to the free energy.

References

External links

{{States of matter Thermodynamics