It applies only to single equilibrium state. It does not indicate other possible equilibrium in the system. Phase rule consider only the number of phase ,but not their quantities . Even a minute quantity of phases when present accounts towards number of phases.
7. What are the limits of phase rule? Explanation: Since phase rule focusses only on one equilibrium state of the system, the presence of even tiny traces of multiple phases cannot be identified using phase rule which is the main drawback of this rule.
1) Phase rule can be applied for a system in equilibrium only. 2) It is not of much help in case of system which attain the equilibrium state very slowly. 3) It is applicable to only single equilibrium state. It doesn't indicate the other possible equilibrium in the system.
Phase diagrams only give information on the constitution of alloys, • such as the number of phases present at a point, but do not give infor- mation about the structural distribution of the phases; that is, they do not indicate the size, shape, or distribution of the phases, which affects final mechanical properties.
It does not furnish enough information regarding the extent of changes when the system shifts from one equilibrium to another. It conditions that all phases of the system must be present simultaneously, under the identical conditions of temperature and pressure.
The phase rule states that F = C − P + 2. Thus, for a one-component system with one phase, the number of degrees of freedom is two, and any temperature and pressure, within limits, can be attained.
5. How many phases are there in Homogeneous reaction? Explanation: Homogeneous reaction is the reaction taking place in only one phases whereas heterogeneous has many phases.
1) It is applicable to both physical and chemical equilibria . 2) It requires no information regarding molecular /micro-structure ,since it is applicable to macroscopic systems . 3) It is a convenient method of classifying equilibrium states in terms of phases ,components and degrees of freedom .
The variables are: the number of phases P (forms of matter—i.e., solid, liquid, and gas—not necessarily of a single chemical component), the number of chemical components C (pure compounds or elements), and the number of degrees of freedom F of intensive variables, such as temperature, pressure, and percentage …