- Concepts of heat, work, and energy
- Laws of thermodynamics
- Enthalpy, entropy, and Gibbs free energy
- Thermochemical equations and Hess's law
- Spontaneity and equilibrium
- Chemical potential and phase equilibria


- Rate of reaction and rate laws
- Order of reaction and rate constants
- Integrated rate equations
- Collision theory and transition state theory
- Catalysis and enzyme kinetics


- Wave-particle duality
- Schrödinger equation and wave functions
- Quantum numbers and atomic orbitals
- Electronic configuration and periodic properties
- Molecular orbital theory and bonding


- Electrochemical cells and cell potential
- Nernst equation and its applications
- Conductivity, molar conductivity, and equivalent conductivity
- Faraday's laws of electrolysis
- Corrosion and its prevention


- Law of mass action and equilibrium constant
- Le Chatelier's principle
- Factors affecting equilibrium position
- Acid-base equilibrium and pH calculations
- Solubility product and precipitation reactions


- Electromagnetic radiation and types of spectroscopy
- UV-Visible spectroscopy and Beer-Lambert law
- Infrared spectroscopy and functional groups identification
- Nuclear magnetic resonance spectroscopy and chemical shifts


- Microscopic and macroscopic systems
- Boltzmann distribution and partition function
- Maxwell-Boltzmann, Fermi-Dirac, and Bose-Einstein distribution functions
- Entropy and probability
- Thermodynamic functions and their relationships


- Crystal structure and unit cells
- Bravais lattices and Miller indices
- X-ray diffraction and determination of crystal structure
- Ionic and metallic solids
- Defects in crystals and their consequences

These topics are frequently asked in the UPSC exam to assess the candidate's understanding of the principles and concepts in physical chemistry. It is important to have a strong foundation in these topics and be able to apply them to solve problems and analyze chemical phenomena.