2. Thermodynamics
Thermodynamics is the science of energy transfer and
its effect on the physical properties of substances.
Thermo = HEAT (or Energy)
Dynamics: Movement
The Temperature - a quantity which indicates how hot
or cold the body is
Temperature is indicator of direction for heat flow.
3. Thermodynamics
Thermodynamics is the science of energy transfer and
its effect on the physical properties of substances.
1. Macroscopic thermodynamics is only
concerned with the effects of the action of many
molecules, and these effects can be perceived by
human senses.
2. The behaviour of the gas is described by
summing up the behaviour of each molecule. Such a
study is made in microscopic or statistical
thermodynamics.
4. Thermodynamic System
• Thermodynamic system is defined as a region
in space upon which attention is concentrated
in the analysis of a problem.
surroundings : Everything external to the system
is called the surroundings or the environment.
boundary : The system is separated from the surroundings
by the system boundary
7. Thermodynamic System
• Truly isolated systems cannot exist in nature,
• The only possibility is the universe itself,
• So its is a hypothetical concepts
http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodynamics/A_System_And_Its_Surroundings
isolated systems
10. Properties
• Thermodynamic properties are observable or
measurable properties of the system(pressure,
temperature, volume)
– Classification of properties
1. Intensive properties (Independent of mas)
Properties have same value in any part of the system and it
is independent of mas (pressure, temperature)
2. Extensive properties (mas dependent)
depends on mass of the system and de not maintain same
value across the system (mass, volume, enthalpy, energy)
11. State
The specific condition of the system is called
State of the system.
the properties are used to describe the
state of the system.
Path : The succession of states passed through
during a change of state is called the path
Process: the path is completely specified, the
change of state is called a process
13. Applications of thermodynamics
•To predict the equilibrium state of a reactive
mixture as well as the natural direction of
change in a system not at equilibrium
•thermodynamics can’t predict how long it
takes for equilibrium to be reached
14. Reference
• Nag, P. K. 2002. Basic and applied thermodynamics. Tata
McGraw-Hill, New Delhi.
• http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodyn
amics/A_System_And_Its_Surroundings
• http://nptel.iitm.ac.in/courses/Webcourse-
contents/IIT%20Kharagpur/Ref%20and%20Air%20Cond/R&AC
%20Web%20files/R&AC%20Lecture%204/hyperlinks/systems.
htm ( date 25-june-2013)