Lab 5 Distillation and Boiling point

Purpose:

Purify a volatile organic compound from an impure mixture by simple microscale distillation

Boiling point

The temperature when a liquid is in equilibrium with its vapor

Equilibrium is the vapor pressure of the liquid

Vapor pressure

The pressure that the molecule exert at the surface of the liquid against external pressure (atmospheric pressure)

Normal Boiling Point

The temperature at which the vapor pressure of a liquid equals atmospheric pressure (1 atm)

Volatile

Easily evaporated at normal temperature

Distillation

The process of separating the component substances of a liquid mixture of two or more chemically discrete substances

Simple Distillation

Involves a single equilibrium b/t the liquid and vapor

-Has one theoretical plate

Fractional Distillation

Uses multiple theoretical plates, separates a mixture of liquids with similar boiling points by heating the mixture and collecting components at different heights in a fractionating column

Molecular weight and surface area

The more, the higher the boiling point

Simple microscale distillation setup

Simple microscale distillation setup Components

Reflux condenser, Clamp and aluminum block, round bottom flask, hickman still, thermometer, and boiling chips

Bumping

the sudden and uncontrolled boiling of a liquid, commonly observed when heating organic liquids

Results

Unknown is hexane