Heating Water and Air in a Sealed Container
Heating Water and Air in a Sealed Container
This Demonstration models the behavior of a container that is mostly filled with water at 25 °C, with air filling the space above the water. The container is then sealed and heated, as in the procedure used in zeolite synthesis. Vary the temperature of the sealed container and the initial volume of water with sliders; the temperature resets to 25 °C when the initial water volume is changed.
As the temperature increases, liquid water expands and its saturation pressure increases. At the same time, the gas-phase volume decreases, so the gas-phase oxygen and nitrogen partial pressures increase, according to the ideal gas law. The quantities of oxygen and nitrogen dissolved in the water increase with pressure but decrease with temperature. The amounts dissolved are shown in the bar chart (green = gas phase, purple = dissolved). Even at moderate temperatures, the pressure inside the sealed container can be quite high.