In today’s session we began an investigation into thermodynamic principles. We observed an exothermic reaction that occurs when baking soda and acetic acid are mixed. We then studied the relationships between pressure, volume, and temperature. We energized (heated) air in a cup, then sealed it to a flat plate using butter. When the temperature decreases, so must the pressure, creating a vacuum that held 500 grams! We briefly looked into the equations that govern these processes.