For a lecture-demonstration experiment, it is desired to construct a sealed glass vial containing a pure substance that can be made to pass through the critical point by heating the vial in a person’s hand. Thus, at room temperature the vial should contain a liquid and its vapor.

(a) From the list of critical properties, select a suitable substance to be sealed within the vial.

(b) What magnitude of pressures must the vial withstand?

(c) For a vial of 100 cm3, how much of the substance should be enclosed in the vial?

(d) Describe the changes within the vial as it is heated if it contains an amount of substance that is less than that calculated in part (c).