This lecture covers the distribution of gas velocities described by the Boltzmann and Maxwell functions, the behavior of real gases using the Van der Waals equation, and the phase transitions of gases. It explains how to determine the distribution of velocities experimentally and the modifications needed in the ideal gas law for real gases. The lecture also discusses the critical temperature and pressure, the coexistence of liquid and gas phases, and the concept of humidity relative to vapor pressure. Additionally, it explores the phase transitions of gases and the importance of studying phase transitions in various states of matter.