Lesson 3.4. Distillation and Boiling Point

constant temperature

A pure liquid generally boils at a ________________________ or over a narrow temperature range, provided the total pressure in the system remains constant.

nonvolatile and volatile impurities

However, the boiling point of a liquid is affected by the presence of both _______________________________, and most mixtures of liquids boil over a fairly wide range.

Simple distillation

allows separation of distillates from less-volatile substances that remain as pot residue at the completion of the distillation

distillate

In the ideal case of simple distillation, only a single component of the mixture will be volatile, so the ________________ will be a pure compound.

greater than 40–50 °C

Simple distillation allows isolation of the various components of the mixture in acceptable purity if the difference between the boiling points of each pure substance is ___________________________.

simple distillation

For example, a mixture of diethyl ether, bp 35 °C (760 torr), and toluene, bp 111 °C (760 torr), could easily be separated by ________________________, with the ether distilling first.

solvents

The ____________ are usually more volatile than the product and are readily removed from it by simple distillation.

Fractional distillation

allows separation of distillates from volatile substances

narrow or near

Fractional distillation allows isolation of the various components of the mixture in acceptable purity if the difference between the boiling points of each pure substance is _____________ each other.