Page 2 - 3.Lesson Note-Distillation, Frac distillation, crystallisation

• This is the process of separation of chemical compounds by their boiling
point.
• The mixture is heated to a temperature at which one or more fractions will
vaporize.

Separation of different components of air

Process of obtaining different gases from the air
Air is a homogeneous mixture and can be separated into its components
by fractional distillation.

Air free from carbon dioxide, water vapour and dust particles is liquefied by applying
pressure and decreasing the temperature. This liquid air contains mainly three
components

o
o
o
Oxygen (b.p.-183 C) Argon ( b.p. -186 C) and Nitrogen (b.p. -196 C). On fractional
nd
st
distillation the different fractions obtained are 1 fraction with lowest b.p Nitrogen, 2
rd
fraction argon and 3 fraction Oxygen.
Fractional distillation of air