Thermodynamic State and Equilibrium
a system does not undergo any change, all the properties have fixed values.
This condition is known as a thermodynamic state.
The word equilibrium
means balance. An equilibrium state of a thermodynamic system is a state that
can not be changed without any interaction with its surroundings. The factors
that cause a change without any interactions with its surroundings are:
If a system is balanced
in all respects, it is in a state of thermodynamic equilibrium. Balanced in all
respects means :
There should not be any temperature
difference within the system, so that the system is thermally balanced.
No pressure difference exists between
any two points within the system (Neglecting gravitational effects) and between
the system and surroundings, so that it is mechanically balanced.
No chemical reaction is taking place, so
that it is chemically balanced.
If two phases are involved, mass of each
phase remains constant so that phase equilibrium is achieved.
Hence, for a system in
a state of thermodynamic equilibrium, there is no change in any macroscopic
BASIC CONCEPTS AND DEFINITIONS
Thermodynamics is the
science of energy transfer which deals with the relations among heat, work and
properties of systems.
The name ‘thermodynamics’ is derived from the
Greek words therme, meaning ‘heat’ and dynamis meaning
power. Thus, thermodynamics is basically the study of heat and power.