Uses (or) Merits and Limitations of Phase Rule

USES (OR) MERITS OF PHASE RULE

1. It is applicable to both physical and chemical equilibria.

2. It is a convenient method of classifying the equilibrium states in terms of phases, components and degree of freedom.

3. It indicates that the different systems having the same degrees of freedom behave similarly.

4. It helps in deciding whether the given number of substances remain in equilibrium or not.

LIMITATIONS OF PHASE RULE

1. Phase rule can be applied only for the systems in equilibrium.

2. Only three variables like P, T & C are considered, but not electrical, magnetic and gravitational forces.

3. All the phases of the system must be present under the same conditions of pressure and temperature.

4. Solid and liquid phases must not be in finely divided state, otherwise deviations occur.