# TD 3

1. Gibbs energy

1. Change in standard gibbs free energy

2. Gibbs excess energy

Raoult’s law for ideal situation

Raoult’s law for real solutions

For azeotropic mixture

2. Equilibrium constant dependency on temperature

3. Equilibrium between two phases ∝ and β
For two phases ∝ and β having two components 1 and 2 with their mole fraction x1 and x2 respectively

4. Gibbs energy and equilibrium constant
Relationship between standard Gibbs energy and equilibrium constant.

5. Change in enthalpy of a reaction
Change in Enthalpy of reaction at a particular temperature T for a reaction

6. Vapour fugacity coefficient and liquid activity coefficient
Relationship between vapour fugacity coefficient and liquid activity coefficient This equation is valid at low-moderate pressure only

Term in bracket depends on temperature, pressure and liquid phase composition only

7. Activity coefficient (ν) and chemical potential (μ)
Relationship between activity coefficient (ν) and chemical potential (μ)

8. Definition of chemical potential

1. Definition of fugacity (f)

For an ideal gas

2. Fugacity coefficient
Fugacity coefficient (ϕ) is defined as

Fugacity coefficient is dependent on temperature, pressure and mole fraction. However, at low pressure it is dependent only on temperature and pressure.

Where: z is compressibility
3. Fugacity of liquid

10. Rate constant and temperature
Dependency of rate constant on temperature

11. Phase rule/ Gibbs phase rule
F = degree of freedom = no. of unknown labelled variables + no. of independent chemical reactions – no. of independent chemical species balance – no. of other equations relating unknown variables.

12. Partial molal enthalpy
Partial molal enthalpy of component i in ideal gas mixture(IGM) is a function of temperature only

13. Vapour-liquid equilibrium
For vapour liquid equilibrium(VLE)

For mixture of non-ideal liquid in equilibrium with its vapour then

Van der Waal’s coefficient a and b are determined by solving the following equations

15. Van laar activity coefficient
Van laar activity coefficient for a binary mixture is given by form

16. Binary non-ideal mixture
Mixture property of binary non-ideal mixture (M) is given by

17. Gibbs Duhem equation

18. Work to separate binary gas mixture
Minimum work required to separate a binary gas mixture at temperature To and pressure Po

19. Lewis-Randall rule

1. Phase Equilibrium
1. The necessary and sufficient conditions for equilibrium between two phases is that temperature, pressure and chemical potential of each component should be same in two phases