Give the definition of an equilibrium.
chemical equilibrium is the state in which both the reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system
What is the criteria for achieving an equilibrium?
The system is in equilibrium with itself and its surroundings. Insulating it will not change the state.
The equilibrium is the state with maximum entropy.
There is no work-, no mass-, and not heat exchange (boundary conditions for this chapter)
Which assumptions are valid for T,P and µ in a two component system in equilibrium (and the defined boundry conditions)?
Describe the Ragone approach for defining an equilibrium.
two states are in equilibrium if no reversible work can be done by changing the system from state 1 to state 2.
this implies that two systems at equilibrium have the same temperature
What does this notation mean?
This notation is used for partial molar quantities.
What is special about the partial molar Gibbs enthalpy?
It is equal to the chemical potential.
Which rule applies to the gibbs enthalpy and the chemical potential in an equilibrium?
What is the definition of a partial molar quantity?
A partial molar quantity is the partial derivative of that quantity with respect to mass (moles) at constant T, P and the mass of the other materials of the system
What does the tilde symbol mean and what is the difference between the it and a patial molar quantity?
The tilde symbol describes a partial molar quantity for constant T and V instead of constant T and P.
How can the general change for the gibbs free enthalpy within one phase in a one component system be described?
How can the change in Gibbs free enthalpy in an ideal gas in a one component system be described?
How can the change in Gibbs free enthalpy in an incompressible solid in a one component system be described?
How can the change in Gibbs free enthalpy in an compressible solid in a one component system be described?
Describe the behaviour of S,V and G in a first order phase transition.
Describe the process of a first order phase transition in words.
A first-order phase transition is a change in the state of matter characterized by a sharp discontinuity in physical properties, such as density, volume and entropy accompanied by a sharp increase in enthalpy
What is the difference between a first and second order phase transition?
First-order phase transitions are characterized by sharp jumps in their physical properties.
Second-order transitions are characterized by continuous changes in physical properties.
Give 2 examples of first order phase transitions
Solid to liquid, liquid to solid
liquid to gas, gas to liquid
solid to gas, gas to solid
What characterizes a second order phase transition?
If the first derivative of the enthalpy over T is continous the oohase transition is of the second order.
Give two examples of a second order phase transition
ferro to paramagnetism for the curie temperature
superconductivity
superfluidity
glass transition
Name the Clapeyron equation.
for reversible and isobaric processes:
What is the application of the clapeyron equation?
The Clapeyron equation defines all the phase borders in a single component phase diagramm.
What is the relation of the chemical potential at a one component phase boundry?
The chemical potentials of both phases are equal.
What is the Simplification of the Clapeyron equation for vapour pressure and name the resulting equation (Clausius-Clapeyron equation)?
The change in the Volume of the solid is neglegiable compared to the gas, which leads to the following equation
What is vapour pressure?
Vapor pressure, also known as equilibrium vapor pressure, is the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases (solid or liquid) at a given temperature in a closed system. It is a measure of the tendency of a substance to evaporate.
What is the notation of the vapour pressure?
What is the effect of pressure on the vapour pressure?
Increasing the pressure increases the vapour pressure
What is the Clapeyron equation for second order phase transitions?
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