Phase Component and Degree of freedom.
Phase:-
A phase is defined as any homogeneous and physically distinct part of a system bounded by a surface and is mechanically separable from other parts of the system.
A phase may be gaseous, liquid or solid. It is perfectly homogeneous and distinct from every other phase that is present in the system. There must be a definite boundary between any two phases. This boundary is known as the interface. Air constitutes a single phase only as it contains a mixture of nitrogen, oxygen, carbon dioxide, water vapor, etc.,.
A system consisting of only one phase is said to be homogeneous. A mixture of two immiscible liquids such as water and benzene will exist in two distinct liquid phases and in addition, there will be a vapor phase. Thus there will be three phases each separated from the other by a well-defined bounding surface.
A system consisting of more than one phase is said to be heterogeneous. When various phases are in equilibrium with one another in a heterogeneous system, there can be no transfer of energy or mass from one phase to another. This means that at equilibrium, the various phases must have the same temperature and pressure and their respective compositions must remain constant all along.
The homogeneous reversible reactions can be studied using the law of mass action.
For heterogeneous reversible reactions, the phase rule given by Williard Gibbs is used.
Degree of freedom:-
Degree of freedom is defined as the minimum number of
independent variable factors such as temperature, pressure, and concentration
of the phases, which must be fixed in order to define the condition
of a system completely. A system having 1,2,3 or 0 degrees of freedom
is called univariant, bivariant, trivariant and nonvariant respectively.
A phase is defined as any homogeneous and physically distinct part of a system bounded by a surface and is mechanically separable from other parts of the system.
A phase may be gaseous, liquid or solid. It is perfectly homogeneous and distinct from every other phase that is present in the system. There must be a definite boundary between any two phases. This boundary is known as the interface. Air constitutes a single phase only as it contains a mixture of nitrogen, oxygen, carbon dioxide, water vapor, etc.,.
A system consisting of only one phase is said to be homogeneous. A mixture of two immiscible liquids such as water and benzene will exist in two distinct liquid phases and in addition, there will be a vapor phase. Thus there will be three phases each separated from the other by a well-defined bounding surface.
A system consisting of more than one phase is said to be heterogeneous. When various phases are in equilibrium with one another in a heterogeneous system, there can be no transfer of energy or mass from one phase to another. This means that at equilibrium, the various phases must have the same temperature and pressure and their respective compositions must remain constant all along.
The homogeneous reversible reactions can be studied using the law of mass action.
For heterogeneous reversible reactions, the phase rule given by Williard Gibbs is used.
Degree of freedom:-
Degree of freedom is defined as the minimum number of
independent variable factors such as temperature, pressure, and concentration
of the phases, which must be fixed in order to define the condition
of a system completely. A system having 1,2,3 or 0 degrees of freedom
is called univariant, bivariant, trivariant and nonvariant respectively.
No comments