Chapter 1
THERMODYNAMICS
Introduction
It is a science of energy transfer and its effect on properties of system
System
A system is a region containing energy and/or matter that is separated from its surroundings by arbitrarily imposed walls or boundaries. In a thermodynamic analysis, the systemis the subject of the investigation.
Surrounding
Everything external to the system is the surroundings.
Boundary
A boundary is a closed surface surrounding a system through which energy and mass may enter or leave the system.
Closed system
Open System
Isolated system (Special case of closed system)
An isolated system is a thermodynamic system that cannot exchange either energy or matter outside the boundaries of the system. There are two ways in which this may occur:
Extensive Properties
An extensive property is a property that depends on the amount of matter in a sample. The mass of an object is a measure of the amount of matter that an object contains.
Intensive Properties
An intensive property is a property of matter that depends only on the type of matter in a sample and not on the amount.
E.g.color, temperature, density, and solubility.
Reversible Process
Irreversible Process
E.g. Heat transfer to finite temperature difference, Free expansion.
THERMODYNAMIC EQUILIBRIUM
(i) Mechanical equilibrium
Net force on a system should be 0, i.e. all the forces should be balanced.
(ii) Chemical equilibrium
All the chemical reactions occuring inside a system should cease after reaching equilibrium state.
(iii) Thermal equilibrium
There should be no heat transfer between the system and surroundings.