The Physical Separation of

Substances

Distillation Filtration •

By: Allan Y, Pauline W, Alex W, and Justus S

•

•

• Evaporation

Recrystallization

Paper Chromatography

Hand Separation

Solvent Extraction

Gravity Separation

Allows for the separation of liquids from

solids

Usually involves a liquid (filtrate) that is

passed through a filter; the material that

remains on the filter is called the residue

Filtration

Filtration

Filtration cannot be used to separate

dissolved solids from a liquid (filtration

only works when the solid particles are big

enough to be seen)

Distillation

As a liquid with the lowest boiling temperature

in the solution boils first, the vapor produced

ascends to the top of the distillation flask, passes

a thermometer, and enters the side-arm of the

flask which leads to the condenser. As the vapor

enters the cold inner surface of the condenser, the

gas cools and condenses back into a liquid,

which drips out the end of the condenser as the

distillate

Hand Separation

Separation of

MECHANICAL

MIXTURES

Can often be separated

by HAND or by use of

SIEVE or MAGNET

Evaporation

Separation of SOLID-IN-LIQUID

SOLUTIONS

Can often be separated by allowing liquid to

EVAPORATE or to be BOILED AWAY,

leaving solid

SOLVENT EXTRACTION

There are two ways in which this

technique can be used …

# 1…

Extraction of a solid from a mechanical

mixture

This method requires a liquid that

dissolves one or more solids present so

the desired product is left behind or

dissolved and separated by evaporation

#2 …

Extraction of a dissolved liquid or solid

from a liquid solution

To carry out this technique, a solution

with one or more solid and/or liquid

substances dissolved in a liquid solution,

a solvent must contain two properties:

The added solvent is immiscible with the

solvent present

The added solvent dissolves one or more

desired substances from the substances and

leaves behind the unwanted

After the solvent is added, the mixture is mixed

in a separatory funnel and the added solvent is

drained from the original solvent

RECRYSTYALLIZATION

Recrystallization is a variation of

evaporation in which a solid in a solid-in-liquid solution is separated in a pure crystalline state

A saturated solution must be prepared in order for recrystallization to occur

A solid is added to a solvent until no more solid can dissolve and adding just enough hot solvent to dissolve the solid, the mixture is allowed to cool and evaporate, forming crystals

Once the crystals have formed, they are

removed by either hand separation or

filtration

Gravity Separation

Separation of two components of a homogeneous mixture

Clarification and thickening are two different products from the same method

Method: in a mix of a solid and liquid, the solid will gradually gather at the bottom of the container while the liquid remains on top

Gravity Separation

Clarification wishes the purified liquid at the end

Thickening wishes the purified solid at the end

When feasible, centrifugal force may also be used in place of gravity (faster separation due to higher pressure upon contents)

Paper Chromatography

Separates small amounts of Solid-in-Liquid

solutions containing two or more dissolved

solids

It requires a drop of the mixture placed near

the end of a sheet of absorbent paper

That end is dipped in the “developing”

mixture

Paper Chromatography

As the solvent gradually travels up the sheet

it will carry along the dissolved solids

The edge of the solvent’s travels is known

as the “solvent front”

Depending on how readily the solids are

dissolved by the solvent, various streaks of

color will appear behind the solvent front

The END!!!!!!!!