Classical Thermodynamics

1
Classical Thermodynamics

• empirical observations
• Natural laws quantum mechanics
• statistical mechanics
• Macroscopic properties

2
Basic Concepts and Definitions

• Systemboundariesenvironment
• (surroundings)
• Primitive properties can be measured

3
Characteristics of Systems

• Simple free of internal boundaries, no external
  forces. (can be formed by one or more than one
  phases.)
• Composite 2 or more simple subsystems separated
  by boundaries.
• Restraints barriers that prevent changes to
  occur.

4
How to determine restraints

• Laws of matter conservation of mass,
  electrical charges, etc.
• Relative magnitudes of rate processes

5
Types of Boundaries

• Impermeable (closed system)
• Permeable or semipermeable (open system)
• Rigid
• Movable
• Adiabatic
• Diathermal
• Impermeablerigidadiabaticisolated

6
Problems in Thermodynamics

• System in a given process, w/constraints and
  boundary conditions.( properties??)
• Given certain changes in props., (external
  interactions??).
• Efficiencies in real processes

7
Steps for solution

• Problem definition and modeling
• Application of thermodynamic laws and
  mathematical reasoning
• Evaluation of property data

8
Problem definition and modeling

• Specify constraints and boundary conditions
• Boundary permeable/impermeable/rigid
• Well-mixed and homogeneous system??
• Heat/mass transfer fast/slow??
• Chemical reactions???

9
Adiabatic vs. Diathermal walls
THERMOMETRIC TEMPERATURE
10
Application of thermodynamics and mathematics

• Initial state N moles at T1, P1
• final state N moles at T2, P2
• ?? is a unique function of the initial
• and final state (state function)
• Mathematical reasoning
• T1, P1 T2, P1 T2, P2

11

• Thermodynamic reasoning

12

• Evaluation of properties
• CPf1(T, P)
• VNVN f2(T, P)
• Experiments, quantum mechanics, statistical
  mechanics
• correlations

13
Phase Equilibrium
14
(No Transcript)