Behavior of Gases

Not carried out.

N.B., the follow-on experiment mentioned at the right was performed with a mercury manometer connected to a side-arm flask. It was difficult to obtain good results, and using a mercury has obvious disadvantages.

Students use the pressure sensor to determine the pressure-volume and pressure-temperature behavior of air.

In a follow-on experiment, students make pressure-temperature measurements to determine the enthalpy of vaporization of a volatile compound. Two sets of pressure-temperature measurements are made. The first is for a sample of air alone. The second is for the same sample of air after a small amount of the volatile liquid is injected through a rubber septum. The data are combined to find the vapor pressure of the volatile liquid alone, as of function of temperature, and thus the enthalpy of vaporization.