III.
Post Lab Questions
1. Discuss the process of sublimation. (5 pts.)
Sublimation is a transition phase from a solid to a gas that does not include an intermediate liquid
phase. The capacity of any sort of solid to sublime is determined by the compound's triple point as
obtained by its phase diagram. A solid must have a greater than typical vapor pressure and weak
intermolecular interactions for sublimation to occur and this is usually the case for solids with
molecules shaped like a sphere or a cylinder. The principle behind the sublimation process is based
on basic chemical properties. Higher temperatures, for example, cause a rise in vapor pressure, which
increases the rate of evaporation. Dry ice or solid carbon dioxide (CO2) is one example of a solid
that undergoes sublimation. Furthermore, there are several methods for performing sublimation. It
might range from a very simple to a more sophisticated technique. A basic one would consist of merely
two Petri dishes, a heat source, and a beaker. This process comprises placing one of the Petri dishes
on the bottom of the beaker containing the crude material and the other dish on top of the beaker.
After heating the crude, the sublimate or purified material will surface on the top dish.
3. The sublimation of naphthalene was performed in a purification experiment. At the beginning of
the technique, 6.9 g of impure naphthalene was obtained. After the purification technique was
completed, 4.7 g of pure naphthalene was recovered. Calculate the percent of naphthalene that
was recovered. Show your solution. (5 pts.)