View source for Physics:Binodal

{{Short description|Graphical curve that denotes a point at which two distinct phases coexist}}
[[Image:LCST-UCST plot.svg|thumb|350px|A phase diagram displaying binodal (coexistence) curves as well as spinodal curves, and lower (LCST) and upper (UCST) critical solution temperatures.]]

In [[Physics:Thermodynamics|thermodynamics]], the '''binodal''', also known as the '''coexistence curve''' or '''binodal curve''', denotes the condition at which two distinct [[Physics:Phase (matter)|phases]] may coexist.  Equivalently, it is the boundary between the set of conditions in which it is thermodynamically favorable for the system to be fully mixed and the set of conditions in which it is thermodynamically favorable for it to phase separate.<ref name="IUPAC">IUPAC binodal curve definition http://old.iupac.org/goldbook/BT07273.pdf {{Webarchive|url=https://web.archive.org/web/20170517050724/http://old.iupac.org/goldbook/BT07273.pdf |date=2017-05-17 }} accessed 2/20/13</ref> In general, the binodal is defined by the condition at which the [[Chemistry:Chemical potential|chemical potential]] of all solution components is equal in each phase.  The extremum of a binodal curve in [[Physics:Temperature|temperature]] coincides with the one of the [[Physics:Spinodal|spinodal]] curve and is known as a [[Critical point (thermodynamics)|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.<ref name="IUPAC"/>

==References==
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==External links==
{{cite thesis |last=Redhi |first=Gyanisavan Govindsamy |date=2003 |title=THERMODYNAMICS OF LIQUID MIXTURES CONTAINING CARBOXYLIC ACIDS |type=Ph.D. |chapter=5.7 Fitting Mathematical Equations to the Binodal Curve Data |page=123 |publisher=University of Natal, Durban, South Africa |url=https://researchspace.ukzn.ac.za/xmlui/bitstream/handle/10413/5045/Redhi_Gyanasivan_Govindsamy_2003.pdf?sequence=1&isAllowed=y |access-date=22 July 2018}}

{{States of matter}}

[[Category:Thermodynamics]]

{{Sourceattribution|Binodal}}