JYU

Applied Geochemistry & Lab

Ch.1 Phase Equilib-ria in a Simple Sys-

tem

Studying the basic principles of Understanding equilibrium assemblage

under a certain T, P, X Estimating T, P, and X from the equilib-

rium assemblages Determining if it’s really in equilibrium

AIMS

Phase (P): A part of the system, which is physicochem-ically homogeneous and mechanically separable from the rest.

Component (C): An operator consisting of the mini-mum number of the operators being capable of repre-senting the compositions of all the phases in the system Depending on the # of C Unary, binary, ternary, quaternary

system, …… Degree of Freedom (F): The minimum # of the inde-

pendent variable required to define the state of the sys-tem. Depending on the # of F bi(di)variant field, univariant

curve, invariant pt.

1. DEFINITIONS

P + F = C + 2

(for two independent variable system)

Can you tell P, C, and T in the following ex-amples?Can you apply the phase rule?

2. Gibbs’ Phase Rule

http://serc.carleton.edu/research_education/equilibria/phaserule.html