1. What substances can be purified by sublimation? What should be noted about the operation of sublimation?

At room temperature, such as iodine monomers and other melting and boiling points of the Krakowski dragon curve of the intersection of the substances closer to the origin, in other words, in the same pressure under the influence of temperature on the state of its more rapid.

If the ultra-low temperature, such as dry ice purification in industry, it is obtained by sublimation of solid air at elevated temperatures.

Sublimation should pay attention to the proper control of the temperature, and the receiving device should have a certain condensation, and can discharge the condensate in time.

If the laboratory method, just add cold water to the bottom of the round-bottomed flask to collect, but also pay attention to the sublimation of the container mouth to be moderate, it is best to use a water bath to heat the experiment.