MY NOTES
Introduction to Thermodynamics in Physical Chemistry:
Thermodynamics is a branch of physical chemistry that deals with the study of energy, heat,
work, and how they interact within chemical systems. It provides a set of principles and laws
that govern the transformation of energy in both physical and chemical processes.
Thermodynamics is crucial for understanding processes such as chemical reactions, phase
changes, and the behavior of gases and liquids.
Key Concepts in Thermodynamics:
System and Surroundings:
System: The part of the universe we are focusing on, such as a
reaction vessel, gas in a container, or a chemical reaction.
Surroundings: Everything else outside the system that can
exchange energy or matter with the system.
The system is the part of the universe being studied, and the
surroundings are everything else.
Types of Systems:
Isolated System: No exchange of energy or
matter with the surroundings (e.g., thermos).
Closed System: Can exchange energy (heat or
work) but not matter with the surroundings
(e.g., a sealed container).
Open System: Can exchange both energy and
matter with the surroundings (e.g., a beaker of water).
State Functions and Path Functions:
State Functions: Properties that depend only on the current state of the system, not on how
the system got there. Examples include temperature (T), pressure (P), volume (V), enthalpy
(H), entropy (S), and internal energy (U).
Depend only on the current state of a system
Do not depend on the path taken to reach that state
Examples include temperature, pressure, volume, and internal energy
Ex: Displacement
The distance between two towns is a state function because it is the same for each route.
Path Functions: Properties that depend on the specific process taken to change the system’s
state, such as heat (Q) and work (W).
Depend on the path taken to reach a particular state
Are influenced by the specific conditions and steps followed during the process
Examples include work and heat
Ex: Work
