This is a course in physical chemistry focusing on statistical thermodynamics, and chemical kinetics. Kinetics of complex reactions: (reversible reactions, consecutive reactions, parallel reactions and chain reaction). Pre-equilibrium, steady-state approximation, Kinetics of the reaction in solution. Statistical thermodynamics and microscopic properties, probability and entropy, Boltzmann distribution law, determination of partition functions and its application, thermodynamics parameter in terms of partition function, partition function of polyatomic molecules (translational, rotational, vibrational, electronic partition function). Equilibria constant in terms of partition function. Calculation of the factor eα and eβ. Velocity Distribution Function of Maxwell-Boltzmann.