#### Fugacity of a Single Component: Screencasts

Explains why fugacity is important for single components and tells how it is used.

We suggest you list the important points in this screencast as a way to increase retention.

Explains how fugacity for a single component changes with temperature and pressure. Uses an interactive simulation to demonstrate the fugacity behavior.

We suggest you list the important points in this screencast as a way to increase retention.

Optional screencast: Fugacity Temperature Dependence: Single Component

##### Important Equations:

Antoine equations 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)
$$A_i, B_i,$$ and $$C_i$$ are constants for a given component, $$i$$

Fugacity of liquid at elevated pressure (Poynting correction):

$f = \phi ^{sat}P^{sat}exp\left( \frac{V^L(P – P^{sat})}{RT}\right)$

where $$V^L$$ is the molar volume of the liquid
$$\phi ^{sat}$$ is the fugacity coefficient at saturation pressure
$$P$$ is the pressure
$$R$$ is the ideal gas constant
$$T$$ is the absolute temperature

Fugacity of solid using Poynting correction:

$f = \phi ^{sat}P^{sat}exp\left( \frac{V^S(P – P^{sat})}{RT} \right)$

where $$V^S$$ is the molar volume of the liquid.

Vapor-liquid phase equilibrium:

$f^L = f^V$

where $$f^L$$ is the fugacity of the liquid
$$f^V$$ is the fugacity of the vapor

Gibbs free energy departure function $$G – G^{ig}$$:

$\frac{G – G^{ig}}{RT} = ln \left( \frac{f}{P} \right) = ln(\phi )$

where $$f$$ is the fugacity
$$\phi$$ is the fugacity coefficient, $$\frac{f}{P}$$