Comprehensive explanation of Fundamental of Engineering Thermodynamics

1. Engineering Thermodynamics
Chapter-1 Introduction
Concept -3: Property, State, Continuum & Equilibrium
Highlights
- Understanding of Concept
- Notes
- Problems
Video link for detailed explanation:
https://www.youtube.com/watch?v=GW5LfqE9KFk&t=64s
By Rahul Agrawal
B.Tech from NIT-Bhopal
M.Tech from IIT-Bombay
GATE AIR: 127, IES qualified
Freelancer Tutor

2. Property, State, Continuum & Equilibrium
Thermodynamic Property:
 Property is a macroscopic characteristic of a system such as mass, volume, energy, pressure, and
temperature
 Even viscosity, thermal conductivity, modulus of elasticity, thermal expansion coefficient, electric resistivity,
and even velocity and elevation are considered as property.
Two types of Properties
i) Intensive : - Properties which are independent of the mass, size or extent of a system of a system
- Intensive properties are not additive
- Example: Temperature, Pressure, and Density.
ii) Extensive: - Properties which are dependent of the mass, size or extent of a system of a system
- properties are additive
- Example Mass, volume, energy,

3. Problems on Property
1. Is the weight of a system an extensive or intensive property?
2. The list consisting only of intensive properties is
(a) volume, temperature, pressure.
(b) specific volume, mass, volume.
(c) pressure, temperature, specific volume.
(d) mass, temperature, pressure.

4. Continuum:
 The concept of continuum assumes a continuous distribution of mass within the matter or system with no
empty space
 homogeneous matter with no holes.
 The continuum idealization allows us to treat properties as point functions
 This idealization is valid as long as the size of the system is large relative to the space between the
molecules.
 The continuum model is applicable as long as the characteristic length of the system is much larger than the
mean free path of the molecules.
 high vacuums or very high elevations, the mean free path may become large
 Rarefied gas flow theory of individual molecules should be considered.
Property, State, Continuum & Equilibrium

5. State of a system:
 The thermodynamic state of a system is defined by specifying values of a set of measurable properties
sufficient to determine all other properties.
Example: the state of an electric battery requires the specification of the amount of electric charge it contains.
Property, State, Continuum & Equilibrium

6. The Concept of ``Equilibrium'‘ :
 No unbalanced potentials (or driving forces) within the system i.e. unchanged values as long as external
conditions are unchanged is called an equilibrium state.
System in thermodynamic equilibrium satisfies:
i) Mechanical equilibrium (no unbalanced forces)
ii) Thermal equilibrium (no temperature differences) : Temperature is the same throughout the entire system,
iii) Chemical equilibrium: chemical composition does not change with time, that is, no chemical reactions occur.
Mechanical equilibrium Thermal equilibrium Chemical equilibrium
Thank You!!
Property, State, Continuum & Equilibrium
Video link for detailed explanation:
https://www.youtube.com/watch?v=GW5LfqE9KFk&t=64s