Question

1.Find the number of components and degree of freedom in \[{\text{NaCl}}\].
2.What is the significance of a triple point?
3.Can four phases in one component system coexist? Why?
4.Define component. Define the number of components in the following equilibria.
\[{\text{N}}{{\text{H}}_{\text{4}}}{\text{Cl}} \to {\text{N}}{{\text{H}}_{\text{3}}}{\text{ + HCl}}\]when \[{\text{N}}{{\text{H}}_{\text{4}}}{\text{Cl}} \to {\text{N}}{{\text{H}}_{\text{3}}}{\text{ + HCl}}\].

Answer 1

Hint: We know that the above questions are related to Phase Rule. Gibbs proposed the phase rule, which explains the existence of equilibrium in heterogeneous systems. Temperature, pressure, and concentration, not gravity, electrical, or magnetic forces, determine the equilibrium between various phases, according to this theory. Phase A is homogeneous, physically distinct, as well as mechanically separable from other portions .

Complete answer:
We know that,
1.\[
  F = C + 2 - P \\
    \\
 \]
     Where, \[F\] is number of degree of freedom or variance
              \[C = \] components in the system
               \[P\] is number of phases in equilibrium
            The number of components for \[{\text{NaCl}}\] is \[2\].
            Now,
             \[
  F = 2 + 2 - 1 \\
   = 3 \\
 \]
2.The significance of the triple point is that it is a pressure and temperature combination that allows all phases of matter to be in equilibrium. Pure water has a triple point of \[0.01\]degrees Celsius and \[4.58\] millimetres of mercury, which is used to calibrate thermometers.

3.In general, in thermal equilibrium, no more than three phases of a substance created from a single component can coexist. This is because the existence of four components would violate the Gibbs Phase Rule.

4.A component is one of a group of chemically unrelated parts that make up a system. The number of components denotes the smallest number of independent species required to define the system's composition across all phases.

\[{\text{N}}{{\text{H}}_{\text{4}}}{\text{Cl}} \to {\text{N}}{{\text{H}}_{\text{3}}}{\text{ + HCl}}\]when \[{\text{N}}{{\text{H}}_{\text{4}}}{\text{Cl}} \to {\text{N}}{{\text{H}}_{\text{3}}}{\text{ + HCl}}\]
Here, the system consists of two phases, solid ammonium chloride and gaseous mixture containing \[{\text{N}}{{\text{H}}_{\text{3}}}\]and \[{\text{HCl}}\]. The components of the mixture, however, are in the same proportion as they are in ammonium chloride. As a result, the composition of both phases can be expressed as ammonium chloride in terms of the same individual. As a consequence, ammonium chloride dissociation is a one-component system.

Note:
It can be noted that the Gibbs phase, also known as the degree of freedom or variance, determines the number of phases. The Gibbs phase rule determines the degree of freedom of a thermodynamically balanced multiphase system.