This slide presentation covers thermodynamics as a topic and the definition of the terms. It also contains principles of thermodynamics

2. 4.0 Basic Thermodynamics
 Thermodynamics is the science of the relationships between heat
and other forms of energy.
 A thermodynamic system is defined as the specified portion of
matter which is separated from the rest of the universe with a
bounding surface.
 It may consist of one or more substances. Boiling water in a beaker is
an example of a thermodynamic system.

3.  The rest of the universe which might be in a position to
exchange matter and energy with the system is termed as
surroundings.
 Consider a reaction between Zinc and dilute H2S04 in a test tube. Here
the test tube forms a system. Everything also around this system is
called surroundings.
4.0 Basic Thermodynamics

4. 4.1 Types of Thermodynamic Systems
 Closed system : In a closed system, exchange of energy with the
surroundings is possible, while matter can neither enter into nor leave the
system.
 Isolated system: In this system, there is no exchange of matter or energy
between the system and the surroundings.
 Open system: In an open system, both matter and energy can enter into
or leave the system and thus there can be an exchange of matter and
energy between the system and the surroundings.

5.  If a system is kept at constant temperature, it is called an isothermal
system.
 If the system is so insulated from its surroundings that no heat flows
in or out of the system, it is called an adiabatic system.
 A system is said to be homogeneous when it consists of only one
phase, i.e., when it is completely uniform throughout.
 For example, a solution of salt is a homogeneous system.
4.1 Types of Thermodynamic Systems

6.  A system is said to be heterogeneous when it consists of two or
more phases, i.e., when it is not uniform throughout.
 For example, a mixture of two immiscible liquids is a heterogeneous
system.
4.1 Types of Thermodynamic Systems

7. 4.2 Thermodynamic Processes
 Isothermal process: A process is said to be isothermal if the
temperature of the system remains constant throughout the whole
process.
This is obtained by making a perfect thermal contact of the system
with a thermostat of a large heat capacity.
 Isobaric process: A process is said to be isobaric if the pressure
remains constant throughout the whole process.

8.  Adiabatic process: A process is said to be adiabatic if no heat is allowed
to enter or leave the system during the whole process.
In such a process, therefore, the temperature gets altered because the
system is not in a position to exchange heat with the surroundings.
It is obtained by having the wall of the system made of perfect heat
insulating substance.
4.2 Thermodynamic Processes

9.  Isochoric process: A process is said to be isochoric if the
volume remains constant throughout the whole process.
 Cyclic process: A process in which a system undergoes a
series of changes and finally comes back to the initial state is
known as a cyclic process.
4.2 Thermodynamic Processes

10. 4.3 Reversible and Irreversible
Processes
 A process which is carried out infinitesimally slowly so that the driving
force is only infinitesimally greater than the opposing force is called a
reversible process.
In short, it is a process which is carried out infinitesimally slowly so
that the driving force is only greater than the opposing force
 In a reversible process, the direction of the process can be reversed at
any point by making a small change in a variable like pressure,
temperature etc.

11.  Any process which does not take place in the above way, i.e., a
process which does not occur infinitesimally slowly, is called an
irreversible process.
 A reversible process cannot be realised in practice, it would require
infinite time for its completion.
4.3 Reversible and Irreversible
Processes

12. 4.4 Thermodynamic Equilibrium
 A system in which the macroscopic properties do not undergo any
change with time is said to be in thermodynamic equilibrium.
 Thermodynamic equilibrium means the existence of three kinds of equilibria in
the system. These are termed as thermal equilibrium, mechanical equilibrium
and chemical equilibrium.

13.  Thermal equilibrium : A system is said to be in thermal equilibrium if there
is no flow of heat from one part of the system to another.
This is possible when the temperature remains the same throughout in all
parts of the system.
 Mechanical equilibrium : A system is said to be in mechanical equilibrium
if there is no mechanical work done by one part of the system or the other.
This is possible when the pressure remains the same throughout in all parts
of the system.
4.4 Thermodynamic Equilibrium

14.  Chemical equilibrium: A system is said to be in chemical
equilibrium if the concentration of the various phases remain the
same throughout in all parts of the system.
4.4 Thermodynamic Equilibrium

15. Group Presentation Assignment

16. Group One: Laws of thermodynamics
Group Two: Enthalpies of formation and Hess’ Law
Group Three: Calorimetry and Gibbs Free Energy
Group Four: Laws of Gases and partial pressures
Group Five: Diffusion structures of solids and liquids and the
concept of intermolecular forces

17.  Submit a write up of not more than three pages
 Illustrate your work with equations and diagrams where applicable.
 Make a seven minutes power point presentation
 Submission and presentation are slated for not later than 8th April
2021