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Ideal-Gas Law and Phase Transitions, Isothermal Atmosphere

Ideal-Gas Law and Phase Transitions, Isothermal Atmosphere: The ideal-gas law is introduced, and the rate of momentum transfer from the gas molecules to the vessel walls is related to pressure. The concepts of phase diagrams and phase transitions are also introduced, and they are explored with fire extinguishers, boiling water, and cooled balloons filled with air. The ideal-gas law holds (approximately) when you have only gas; it doesn’t hold whenever there is any liquid present. Professor Lewin uses a demo of water boiling at room temperature but low pressure.