Final answer:
Vacuum distillation has a lower boiling point than simple distillation because it reduces the pressure above the liquid, thereby decreasing the boiling point and allowing for the distillate to be collected at lower temperatures.
Step-by-step explanation:
The main difference between simple and vacuum distillation in terms of boiling point is that vacuum distillation has a lower boiling point.
This is because by reducing the pressure above a liquid in vacuum distillation, you reduce the boiling point of the substance, enabling the distillation of compounds at temperatures lower than their standard boiling points. This process is beneficial for separating mixtures of liquids that may decompose or react at high temperatures.
In contrast, simple distillation is carried out at atmospheric pressure, where the boiling points of the liquids remain unchanged, and thus the temperature required to boil the liquid is higher.
For example, water boils at 100°C at atmospheric pressure during simple distillation, whereas under vacuum conditions, the boiling point can be significantly lower.