The document discusses different methods for separating mixtures, including sieving, decanting, gravity separation, evaporation, filtration, magnetic separation, and re-crystallization. Each method is described and an example is given of how it could be used, such as using sieving to separate nails from toothpicks or magnetic separation to remove iron filings from sand. The key is choosing the appropriate separation technique depending on the type of mixture and properties of the substances involved.

1. Separating Mixtures

2. Separating Mixtures
Different methods of separating are used
depending on the type of mixture we need
to separate and the properties of the
substances making it up.
Sieving
Decanting
Gravity Separation
Evaporation
Filtration
Magnetic Separation
Re-crystallisation

3. Separating Mixtures

4. Separating Mixtures

5. Separating Methods Assessment
Separation Method Description of the Separating Method Example of the Separation Method
Magnetic Separation
Used for separating solids of different density/weights. A stream of water is
used to move the light particles away from the heavier particles.
Removing and collecting salt from salt water.
Sieving
A method used to separate solutions. The unwanted liquid is removed via
evaporation, leaving the solid behind. Removing a bunch of nails from a bunch of
toothpicks
Evaporation
Used if a higher purity is required. A solvent is used to dissolve the mixture,
the solvent is then evaporated off to make a saturated solution. Crystals are
then made by seeding the solution, only a pure substance will form,
impurities are left in the solution. Taking the dirt out of muddy water
Filtration
Used when separating two solids, where particles of one solid are larger
than particles of the other solid. Use of sieves, containers with different
sized holes to allow certain sized particles through. Removing water from a bucket of river pebbles
Re-crystallisation
Used to separate solids, where one of the solids is magnetic. A large
magnet attracts to it the magnetic material any other material passes
straight by thus separating the mixture. Removing the lumpy bits from a cup of cocoa
Gravity Separation
Used to separated solids from liquids. A special type of paper, known as
filter paper traps the solid as the liquid is allowed to pass straight through.
Making nice pure sugar crystals
Decanting
Not a perfect method of separation. Used for separating a solid from a
liquid. Involves carefully pouring a liquid off once the solid particles have
settled to the bottom of the container. Some liquid remains.
Panning for gold.
Separation Method Description of the Separating Method Example of the Separation Method
Magnetic Separation
Used for separating solids of different
density/weights. A stream of water is used to move
the light particles away from the heavier particles.
Removing and collecting salt from salt
water.
Sieving
A method used to separate solutions. The unwanted
liquid is removed via evaporation, leaving the solid
behind.
Removing a bunch of nails from a bunch
of toothpicks
Evaporation
Used if a higher purity is required. A solvent is used to
dissolve the mixture, the solvent is then evaporated
off to make a saturated solution. Crystals are then
made by seeding the solution, only a pure substance
will form, impurities are left in the solution.
Taking the dirt out of muddy water
Filtration
Used when separating two solids, where particles of
one solid are larger than particles of the other solid.
Use of sieves, containers with different sized holes to
allow certain sized particles through.
Removing water from a bucket of river
pebbles
Re-crystallisation
Used to separate solids, where one of the solids is
magnetic. A large magnet attracts to it the magnetic
material any other material passes straight by thus
separating the mixture.
Removing the lumpy bits from a cup of
cocoa
Gravity Separation
Used to separated solids from liquids. A special type
of paper, known as filter paper traps the solid as the
liquid is allowed to pass straight through.
Making nice pure sugar crystals
Decanting
Not a perfect method of separation. Used for
separating a solid from a liquid. Involves carefully
pouring a liquid off once the solid particles have
settled to the bottom of the container. Some liquid
remains.
Panning for gold.

6. Separating Methods Assessment
Separation Method Description of the Separating Method Example of the Separation Method
Magnetic Separation
Used for separating solids of different density/weights. A stream of water is
used to move the light particles away from the heavier particles.
Removing and collecting salt from salt water.
Sieving
A method used to separate solutions. The unwanted liquid is removed via
evaporation, leaving the solid behind. Removing a bunch of nails from a bunch of
toothpicks
Evaporation
Used if a higher purity is required. A solvent is used to dissolve the mixture,
the solvent is then evaporated off to make a saturated solution. Crystals are
then made by seeding the solution, only a pure substance will form,
impurities are left in the solution. Taking the dirt out of muddy water
Filtration
Used when separating two solids, where particles of one solid are larger
than particles of the other solid. Use of sieves, containers with different
sized holes to allow certain sized particles through. Removing water from a bucket of river pebbles
Re-crystallisation
Used to separate solids, where one of the solids is magnetic. A large
magnet attracts to it the magnetic material any other material passes
straight by thus separating the mixture. Removing the lumpy bits from a cup of cocoa
Gravity Separation
Used to separated solids from liquids. A special type of paper, known as
filter paper traps the solid as the liquid is allowed to pass straight through.
Making nice pure sugar crystals
Decanting
Not a perfect method of separation. Used for separating a solid from a
liquid. Involves carefully pouring a liquid off once the solid particles have
settled to the bottom of the container. Some liquid remains.
Panning for gold.
Separation Method Description of the Separating Method Example of the Separation Method
Magnetic Separation
Used for separating solids of different
density/weights. A stream of water is used to move
the light particles away from the heavier particles.
Removing and collecting salt from salt
water.
Sieving
A method used to separate solutions. The unwanted
liquid is removed via evaporation, leaving the solid
behind.
Removing a bunch of nails from a bunch
of toothpicks
Evaporation
Used if a higher purity is required. A solvent is used to
dissolve the mixture, the solvent is then evaporated
off to make a saturated solution. Crystals are then
made by seeding the solution, only a pure substance
will form, impurities are left in the solution.
Taking the dirt out of muddy water
Filtration
Used when separating two solids, where particles of
one solid are larger than particles of the other solid.
Use of sieves, containers with different sized holes to
allow certain sized particles through.
Removing water from a bucket of river
pebbles
Re-crystallisation
Used to separate solids, where one of the solids is
magnetic. A large magnet attracts to it the magnetic
material any other material passes straight by thus
separating the mixture.
Removing the lumpy bits from a cup of
cocoa
Gravity Separation
Used to separated solids from liquids. A special type
of paper, known as filter paper traps the solid as the
liquid is allowed to pass straight through.
Making nice pure sugar crystals
Decanting
Not a perfect method of separation. Used for
separating a solid from a liquid. Involves carefully
pouring a liquid off once the solid particles have
settled to the bottom of the container. Some liquid
remains.
Panning for gold.