The process of distillation under reduced pressure, often referred to as vacuum distillation, is commonly used for the purification of sensitive liquids. The reason for utilizing reduced pressure in this process is primarily to lower the boiling point of the liquid being distilled.
By reducing the pressure in the distillation apparatus, the surrounding pressure exerted on the liquid is decreased. This reduction in pressure lowers the boiling point of the liquid, allowing it to vaporize and be collected at a lower temperature than it would at atmospheric pressure.
Sensitive liquids, such as those prone to decomposition, degradation, or evaporation at high temperatures, can be purified more effectively using vacuum distillation. By distilling the liquid at lower temperatures, the risk of thermal degradation or other undesirable reactions is minimized.
Additionally, reduced pressure distillation can help to remove impurities with high boiling points or compounds that may decompose at elevated temperatures. These impurities might otherwise contaminate the distilled product or interfere with its desired properties.
Overall, vacuum distillation provides a controlled environment that allows for the purification of sensitive liquids with reduced thermal stress and improved preservation of their desired characteristics.