# Enthalpic Excess Function - Phase Separation in Regular solutions

1. May 22, 2014

### elemis

I disagree with him partly. For $\Delta_{mix} G/nRT<0$ mixing is spontaneous and hence there solutions would be miscible. Hence at $\beta=2.5$ should we not expect the components to be fully miscible. ?

Following on from this logic; for $\beta=3$ the components are only miscible for $\Delta_{mix} G/nRT<0$ so the maxima represents a phase separation between the two components.

Who is correct ?

Additionally,the webpage below indicates that at the maxima there is one phase whilst at the minima there are two. Does this mean at the maxima the solutions are miscible ? If so, how can this be true given that $\Delta_{mix} G/nRT<0$ is positive and hence mixing is unfavourable ?

http://www.chm.bris.ac.uk/~chdms/Teaching/Chemical_Interactions/page_17.htm [Broken]

Last edited by a moderator: May 6, 2017
2. May 22, 2014

Any ideas ?