Distillation and Sublimation

Distillation and Sublimation

The process of heating a liquid and turning it into gas is called evaporation
or vaporization. When water from a hot tea is converted to vapors, that is an
example of vaporization.

Again, if we cool that vapor, the vapor turns into liquid. This process is
called condensation. For example, water vapor emits heat and turns into water,
which is condensation. The process of heating a liquid into vapor and then
retrieving the liquid from the vapor by cooling it is called distillation.

That means, Distillation = Vaporization + Condensation

The process in which heating a solid directly turns that solid into a
gaseous substance instead of a liquid is called sublimation.

Ammonium Chloride (NH₄Cl), Camphor (C₁₀H₁₆O),
Naphthalene (C₁₀H₈), Solid Carbon-dioxide
(CO₂), Iodine (I₂) Aluminium Chloride
(AlCl₃), etc. are matters that do not turn liquid if heat is
applied. Instead, they vaporize. These substances are called sublimated
substances.

Experiment-1:

Take some solid aluminum chloride salt in a beaker. Put a glass lid on its
open face. Put some ice cubes on the lid. Now, apply heat slowly to the
beaker. You’ll see the solid AlCl₃ is turning into a gaseous
form absorbing heat. This gaseous AlCl₃ again reaches the lid
and under the influence of ice, condenses itself underneath the lid.

If a sublimated substance is mixed with some solid matter, it can be retrieved
by means of the sublimation process. For example, if some ammonium chloride
(NH₄Cl) is mixed with some edible salt (NaCl), it can be separated
by the process of sublimation. If heat is continuously applied to the
sublimated substance, it vaporizes. In iodized salt, iodine is a sublimated
substance. If you apply heat to that salt, the iodine will be vaporized from
there.

The vapor can be cooled into solid iodine. However, since the mixture of sand
and glucose does not contain any sublimated substance, therefore, you cannot
separate them by sublimation.