What happens to the temperature as vapors rise in the fractional distillation tower?

In fractional distillation, as vapors rise through the distillation tower, the temperature decreases. This phenomenon occurs due to the fact that the vapor interacts with the cooler surfaces of the tray or packing material within the column. As the vapor rises, it cools down, leading to condensation of the more volatile components and the less volatile components continuing to rise.

This temperature gradient is crucial to the separation process because it encourages the different components in the mixture to condense at varying heights in the column, depending on their boiling points. The more volatile substances will retain gaseous form longer and ascend higher in the column before condensing, while the less volatile substances will condense at lower heights.

Understanding this temperature behavior is essential for grasping the principles of fractional distillation, which is used to separate mixtures based on differences in boiling points.