Transcript Separations Magnets Settling Decanting Filtering Evaporation Distillation Chromatography Writing Down Results When you do a scientific investigation make sure you WRITE DOWN your RESULTS.

Separations
Magnets
Settling
Decanting
Filtering
Evaporation
Distillation
Chromatography
Writing Down Results
When you do a scientific investigation make
sure you WRITE DOWN your RESULTS.
Magnets
What
How
could
types
you
ofattract
materials
separate
will
a mixture
magnets
of
attract?
sulfur and
filings?as well).
By
Magnets
using
will
a MAGNET!
IRON,
STEEL
(NICKEL
andiron
COBALT
Separating iron and sulfur
1. Your teacher will give you a mixture of
iron and sulfur and a magnet.
2. Wrap the magnet in a paper-towel.
3. Use the magnet to separate the iron
filings from the sulfur.
Questions
1. What did you observe?
The iron filings are attracted to the magnet.
2. Could you use a magnet to separate gold
and sulfur?
No, gold is not magnetic.
Exercise 1: Describe How You Could Use a
Magnet to Separate some Steel Coins from
some Copper Coins
Settling
Separating sand and water
1. Fill a beaker with water.
2. Add some sand to the water.
3. Stir the sand using a glass rod. What
do you observe?
4. Wait a couple of minutes. What can
you see now?
What happened?
The sand particles are pulled to the base of the beaker by GRAVITY.
Extension activity
Repeat the experiment above but instead of just sand use a mixture
of sand and gravel. What do you observe?
Decanting
Separating sand and water
1. Take a beaker containing water with
sand settled at the bottom.
2. Carefully pour away the water whilst
trying not to disturb the sand.
3. How clean is the water you have
poured off (decanted)?
Is there a better method of separating sand and water?
It is very difficult using the decanting method to obtain pure water
that contains no sand particles. There is a better way of separating
sand and water, we will look at that next.
Filtration
Separating
By
using
could
FILTER
sand
you use
PAPER.
and
a water
similar
Filter
method
paper
to
contains
separate
small
sand
holes
If How
By
you
using
have
a
sieve!
cooked
some
pasta
in
a pan
at
home,
how
that
andwill
water?
let liquidsthe
pass through
but pasta?
not insoluble solids.
do
separate
froma the
1. you
Your
teacher willwater
give you
mixture of
sand and water.
2. Set up the apparatus as shown on the
right.
3. Take a piece of filter paper and fold it
in half, then fold it in half again.
4. Open up a ‘pocket’ in the filter paper
and place it in the filter funnel.
5. Carefully pour the mixture of sand and
water through the filter paper.
6. Note your observations.
Exercise 2: Filtrate and Residue
Residue
1. Which substance was left on the filter paper
(this is called the RESIDUE)?
The sand was the residue.
2. Which substance passed through the filter
paper (this is called the FILTRATE)?
Water was the filtrate.
3. Could you use the filtration method to separate
salt and water?
No, salt is soluble in water and would therefore
pass through the filter paper with the water.
Filtrate
Evaporation
The
When
If
How
youwater
could
heat
wet clothes
on
a
you
solution
the
use
clothes
are
a of
similar
left
salt
evaporates
onand
method
a washing
waterto
(changes
and
separate
linethen
theyleave
salt it for a few
Separating
salt
and
water
eventually
days
and
from
water?
athe
liquid
water
become
into
will
a gas).
EVAPORATE
dry.
Why?
and leave the salt behind.
1. Your teacher will give you a solution of
salt and water.
2. Set up the apparatus as shown on the
right.
3. Pour some of the solution into the
evaporation dish.
4. Place the evaporation dish onto the
gauze.
5. Heat the solution for 30 seconds using
a blue Bunsen flame.
6. Let the evaporation dish cool and then
leave in a safe place for a few days.
7. After a few days note down your
observations.
Evaporation
You can separate a soluble solid from a liquid using evaporation.
When a liquid evaporates it changes into a gas.
If a solid is dissolved in the liquid,
when the liquid evaporates the
solid is left behind.
If you heated some water that
had salt dissolved in it, then the
water would evaporate leaving
behind crystals of salt.
If you go swimming in the sea on
a sunny day, evaporation can
cause salt crystals to be left on
your skin.
Exercise 3: Evaporation Results
1. What was left behind in the evaporation dish after a few days?
Crystals of salt.
2. Where did the water go to?
It evaporated (changed from a liquid to a gas) and went into
the air.
3. Could you use this method to collect water?
No, if you wish to separate salt and water, whilst collecting both
substances you would need to use another method.
Exercise 4: Plan an Investigation
Your task is to plan an experiment that will allow you to
separate a mixture of soot and copper sulfate.
You will then perform your investigation.
Soot is a substance that is insoluble in water.
Copper sulfate is a substance that is soluble in water.
You must be able to collect the soot and the copper
sulfate.
You can use any standard laboratory apparatus you may
require.
Distillation
Separating salt and water
1. Your teacher will give you a solution of salt and water.
2. Set up the apparatus as shown below.
Leibig
Condenser
3. Add some of the solution into the flask.
Delivery tube
4. Fit the delivery tube and bung into
the conical flask.
5. Heat the solution using
a blue Bunsen flame.
6. Note your
observations.
Distillate
Bung
Exercise 5: Distillation
1. At what temperature does water boil?
100ºC
2. What was left in the conical flask at the end of the experiment?
Salt
3. In the delivery tube, boiled water condenses, what does the
word condense mean?
A gas changes into a liquid
Research homework
1. What does the Leibig condenser do?
2. Find out two uses of distillation in industry.
Chromatography
1. Take a piece of filter paper and
draw a large dot in the middle with a
coloured felt-tip pen.
2. Then using a dropper add a couple
of drops of water onto the ink dot.
3. Write down what you observe.
What did you observe?
The ink drop separates out into
colours. The pattern you get
depends upon the colour of
felt-tip pen you use.
Exercise 6: Chromatography
1. Four coloured felt-tip pens produce the ink patterns below.
a) Which ink dot contains only one colour?
b) Which ink dot contains three colours?
c) Which two ink dots contain two colours?
A
D
B&C
Exercise 7: Link the Separation Techniques
Iron and sulfur
Chromatography
Evaporation
Sand and water
Ink from water
Distillation
Salt from water
Filtration
Colours in brown ink
Magnet
Exercise 8: Write a Sentence about Each of the
Words Below
Decanting
Pouring off the liquid leaving the solid
behind
Settling
Letting gravity pull the solid particles to
the bottom of a liquid
Filtering
Using filter paper to separate an
insoluble solid from a liquid
Evaporation
Using heat to change a liquid into a
gas, leaving a soluble solid behind
Chromatography
Using water to separate colours