Heat Capacity and Degrees of Freedom in Thermodynamics

This lecture discusses the concepts of heat capacity and degrees of freedom in thermodynamics. It begins with an overview of heat capacity for various gases, including monatomic, diatomic, and polyatomic molecules. The instructor explains how the internal energy of a gas is influenced by its degrees of freedom, which are determined by the types of molecular motion: translational, rotational, and vibrational. The lecture emphasizes the importance of understanding how these motions contribute to the heat capacity of different molecules. The instructor also introduces the Mayer relation, which connects heat capacities at constant pressure and volume. The discussion includes practical examples, such as calculating the degrees of freedom for specific molecules like CO2 and H2O, and how temperature affects the activation of vibrational modes. The lecture concludes with a focus on the first law of thermodynamics and the significance of state functions in thermodynamic processes, highlighting the differences between work and heat as state functions.