#Ternary diagram heaviest component plus#

The critical point (on a phase diagram) can only exist at one temperature and pressure for a substance or system and thus the degrees of freedom at any critical point is zero.ДЄn Example of the Phase Rule: 1 Component SystemВ :Take the generic 1 component phase diagram below (from class). The degrees of freedom of a system dictate the number of phases (as described above in the bullet list) that can occur in the system. The number of chemical components (C in the equation above) in addition to the 'extensive variables' (temperature and pressure) comprise the 'variables' of a system. The Phase Rule describes the number of variables (and equations) that can be used to describe a system (at chemical equilibrium). Essentially, the degrees of freedom of a system describe the dependency of parameters such as temperature and pressure on each other. The 'degrees of freedom' of the system (at chemical equilibrium) refer to the number of conditions or variables that can be altered, independent of each other, without effecting the number of phases in the system.

the 2 comes from the extensive variables Temperature and Pressure.

#Ternary diagram heaviest component plus#

The Phase Rule States: the degrees of freedom of a system is equal to the number of components minus the number of phases plus two.

C: The number of components (that make up the phases).

Similarly, higher component systems may have phases made up of multiple components (ie a phase can be composed of more than one component). For example, ice and liquid water are two separate phases in a one component system (H20). A phase can be a pure compound (say water for example) or a mixture (solid or aqueous), but the phase must 'behave' as a consistent substance.

P: The number of phases that can coexist any separable material in the system.

F: The degrees of freedom of the system see below.

Key words: Phase rule, Phase diagrams, Ternary phase diagram, Three component system.Definition: Phase Rule (Gibbs' Phase Rule) The review focuses on the concept of phase diagram and phase rule, various methods and rules relating to ternary phase diagrams, various examples and its recent applications in pharmaceutical research. Ternary phase diagrams give the precise and accurate data of the various composite component systems and are utilized in several areas of pharmaceuticals like the formulation of various dosage forms, polymer coating methods and several other formulation processes. A ternary phase diagram has the shape of a triangular prism with an equilateral triangle as a foundation which is used to describe a three component system. A phase diagram is a graphical representation composed of area curve, lines and points, which is used to describe a specific system composed of a single or multiple components and generate the data with respect to concentration of different components, temperature and pressure at which thermodynamically distinct phases occur, transform from one phase to another and coexist at equilibrium. Phase diagram serves as an important tool for screening of such formulation components. Various pharmaceutical formulations such as emulsion, micro emulsions and gels are mainly composed of lipid soluble component, water soluble component, surfactant and cosolvents. The phase rule given by J.W Gibbs in 1874 is applied to define a system composed of single component as well as multi-component.

A phase is a physically discrete and chemically homogeneous portion of a system, separated by boundaries from other portions of the system.