Final answer:
The statement about twin column distillation is true; as the descending alcoholic wash warms the rising vapors in the rectifier, it causes heavier alcohols to condense on the spirit plates.
Step-by-step explanation:
The statement provided in the question is True. In a twin column distillation system, often used for the purification of alcoholic beverages, the alcoholic wash descends in the rectifier where it comes into contact with rising alcoholic vapors. This process warms the vapors, causing heavier alcohols to condense on individual spirit plates. The heat exchange that takes place in the rectifier is essential for the separation of different components based on boiling points. As in fractionation of crude oil, substances with a higher boiling point will condense at lower levels of the column, whereas substances with a lower boiling point will condense at higher levels and are drawn off accordingly.
The utility of this process can also be explained by considering the thermal expansion of liquids, like alcohol in a thermometer. When a cold alcohol thermometer is placed in a hot liquid, the liquid inside the thermometer initially contracts slightly due to the immediate cooling effect of the colder glass on the liquid�s exterior, before expanding and causing the column of alcohol to rise. This is an example of the physical behavior of liquids when subjected to changes in temperature, not directly related but illustrates the general principle of thermal dynamics within a system.