Physical Chemistry: Branches and Principles

Physical Chemistry

Branches of Physical Chemistry

• Thermochemistry: study of heat changes in chemical reactions
• Chemical Kinetics: study of rates of chemical reactions
• Electrochemistry: study of chemical reactions involving electron transfer
• Quantum Mechanics: study of behavior of atoms and molecules at atomic and subatomic level
• Spectroscopy: study of interaction between matter and electromagnetic radiation

Laws and Principles

• Zeroth Law of Thermodynamics: if two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other
• First Law of Thermodynamics: energy cannot be created or destroyed, only converted from one form to another
• Second Law of Thermodynamics: total entropy of an isolated system always increases over time
• Third Law of Thermodynamics: as temperature approaches absolute zero, entropy approaches a minimum value

Important Concepts

• Thermodynamic Systems: isolated, closed, and open systems
• State Functions: properties that depend only on the current state of the system, not on the path by which it was reached (e.g. internal energy, entropy)
• Phase Equilibria: equilibrium between different phases of a substance (e.g. solid-liquid, liquid-gas)
• Chemical Potential: measure of the energy associated with a substance's chemical reactions

Physical Chemistry

Branches of Physical Chemistry

• Thermochemistry is the study of heat changes in chemical reactions.
• Chemical Kinetics is the study of rates of chemical reactions.
• Electrochemistry is the study of chemical reactions involving electron transfer.
• Quantum Mechanics is the study of behavior of atoms and molecules at atomic and subatomic level.
• Spectroscopy is the study of interaction between matter and electromagnetic radiation.

Laws and Principles

• The Zeroth Law of Thermodynamics states that if two systems are in thermal equilibrium with a third system, they are also in thermal equilibrium with each other.
• The First Law of Thermodynamics states that energy cannot be created or destroyed, only converted from one form to another.
• The Second Law of Thermodynamics states that the total entropy of an isolated system always increases over time.
• The Third Law of Thermodynamics states that as temperature approaches absolute zero, entropy approaches a minimum value.

Important Concepts

Thermodynamic Systems

• Isolated systems exchange neither matter nor energy with the surroundings.
• Closed systems exchange energy but not matter with the surroundings.
• Open systems exchange both matter and energy with the surroundings.

State Functions

• State functions are properties that depend only on the current state of the system, not on the path by which it was reached.
• Examples of state functions include internal energy and entropy.

Phase Equilibria

• Phase equilibria occurs when a substance is in equilibrium between different phases (e.g. solid-liquid, liquid-gas).
• The equilibrium is characterized by equal chemical potential of the substance in each phase.

Chemical Potential

• Chemical potential is a measure of the energy associated with a substance's chemical reactions.
• It is a driving force behind chemical reactions and phase transitions.

Explore the various branches of Physical Chemistry, including Thermochemistry, Chemical Kinetics, and more. Learn about the fundamental laws and principles that govern chemical reactions and interactions.