Question

distillation lab

explain why the boiling point rises during distillation

Answer 1

The observation that the boiling point of a pure material does not change during the course of distillation is an important property of a pure material.

The boiling point and boiling point range have been used as criteria in confirming both the identity and purity of a substance.

For example, if we synthesized a known liquid that boiled at 120-122 °C, this value could be used to confirm that we prepared what we were interested in and that our substance was reasonably pure.

Of course, additional criteria must also be satisfied before the identity and purity of the liquid are known with certainty. In general, a boiling point range of 1-2 °C is usually taken as an indication of a pure material.