Antoine equation for component \(i\):

\[log_{10} (P^{sat} _i ) = A_i – \frac{B_i}{C_i +T}\]

where \(P^{sat} _i \) is the saturation pressure, \(T\) is the temperature (most often in °C), and \(A_i, B_i,\) and \(C_i\) are constants for a given component \(i\).

Gibbs Phase Rule for non-reactive system:

\[F = 2 + C – P\]

where \(F\) is the number of degrees of freedom, \(C\) is the number of components, and \(P\) is the number of phases.

Quality (\(q\)) of a fluid:

\[q = \mathrm{\frac{ vapor \hspace{1.5mm} mass}{total \hspace{1.5mm} mass}}\]

See this video for more information on various single-component phase diagrams.