Y9 Science: Matter, Mixing and Separating

At the end of this unit you will be able to……………

1 Describe the macroscopic properties of the states of

matter and explain why solids, liquids and gases are used

for particular jobs in terms of their macroscopic

properties.

2 Measure density and compare the density of different

materials

3 Name the changes of state and relate these changes to the

loss or gain of energy

4 Use a particle model to explain the properties of solids,

liquids and gases, and discuss what happens to the

particles when a substance changes state

5 Explain diffusion in terms of particle behaviour

6 Explain expansion and contraction of a substance in

terms of particle behaviour

7 Find by experiment whether substances are soluble or

insoluble; distinguish between solutes and solvents; create

saturated solutions and explain the effect of temperature

on solubility

8 Describe the difference between a solution and a

suspension

Habits of Mind development

9 Separate suspensions by the following techniques, and

explain what happens: decanting, centrifugation and

filtration (distinguish between a residue and a filtrate)

10 Separate solutions by the following techniques to re-gain

either the solvent or the solute, and explain what happens:

evaporation and distillation

11 Use and explain a variety of techniques for separating

solids to include: magnetism, gravity

12 Separate different solutes from a solution by

chromatography and explain what happens

13 Evaluate the different separation methods and identify a

suitable method to separate various mixtures

14 Be able to use each word from the list below in a sentence

(that makes sense)

By the end of the unit you should have developed your ability to....

15 Question and Pose Problems

16 Applying past knowledge to new situations

17 Create, Imagine and Innovate

18 Remaining open to continuous learning

19 Thinking Interdependently

20 Persisting

You should be able to define these words and write intelligent

sentences using them:

Matter

Mass

Volume

States of matter

Density

Changes of state

Melting

Evaporation

Boiling

Solidify

Sublimation

Reverse

sublimation

Particles

Particle theory

Theory

Expand

Boiling point

Diffusion

Contract

Conductor (of

heat)

Insulator (of heat)

Properties

Pure substances

Mixtures

Solution

Solute

Solvent

Soluble

Insoluble

Suspension

Dilute

Concentrated

Saturated

Solubility

Decanting

Centrifuge

Filtering

Residue

Filtrate

Distillation

Chromatography

Activity 1.1 Compressing solids, liquids and gases.

1. Carry out the following activities and record your

observations below: Put your thumb over the end of the

syringe and push the plunger in.

Syringe with air Syringe with water syringe with sand

2. Write inferences for each of the syringes:

Air filled:

Water filled:

Sand filled:

Activity 1.2 Describing Matter

1. List the properties of solids liquids and gases in the table

(think about particle proximity, particle movement and shape

and volume)

Solid Liquid Gas

2. Name the two states of matter that can change shape –

explain why they can.

3. Explain why you can pour sand even though it is a solid.

4. Explain how you can prove that you cannot change the

volume of a solid or liquid.

5. Why do gases take the shape of their container?

Activity 1.4 Heating Ice

Your teacher will give you some crushed ice, a conical flask and a

balloon. Set up a Bunsen and tripod with gauze as shown below.

OBSERVATIONS

Before heating During heating During cooling

Take photographs at each stage.

Inferences (explanations using scientific knowledge).

Record your observations as you heat

flask over the Bunsen and then as you

allow it to cool (lift it off the tripod and

onto the heat proof mat. Then write an

explanation about what is happening in

the flask and to the ice/water particles

and give reasons for your observations.

Activity 1.4 Describing phase changes

1. Write the phase change names beside:

Solid → liquid

Liquid → solid

Liquid → gas

Gas → liquid

Gas → solid

Solid → gas

2. Fill in the gaps in the diagram

Liquid

Gas Solid Gas Liquid

3. Complete the table:

Phase change Heat energy in or out?

Melting

Subliming

Freezing

Evaporating

Reverse subliming

condensing

4. Complete the table:

Phase change situation

Frost forms on grass

Ice-cream becomes liquid

Fruit juice is made into ice-blocks

Water forms on the mirror in the

bathroom

Dry ice ‘smokes’

The kettle boils

5. Explain why water forms on the outside of a glass of

iced drink.

6. Explain why your glasses ‘steam up’ when you open the

oven door?

7. Decide whether each statement is true or false.

Write corrected statements for the false one (underneath

the false statement)

A Solids have a fixed shape. T/F

B Matter is anything that exists.

C Liquids and solids can be poured.

D Particles in gases move fast and are not attracted

to each-other.

E Liquids take the shape of their container as the

particles are not attracted to each-other.

F The particles in solids can move around each-

other

G Gases and liquids have a fixed volume.

H As the temperature increases the particles in all

states move more.

I Solids have a fixed shape.

J Matter is anything that exists.

8. Complete the following sentences:

a. In solids the particles ______ because the particles cannot

_______.

b. Diffusion occurs in ______ and ______ because the

particles are moving.

c. Solids have a fixed shape because…….

d. Write a paragraph about the information in the diagram:

Activity 2.1 Measuring Density

Your teacher will give some objects and ask you to find their

density. You will need to find the mass of each object first and

then their volumes. You will need to exactly measure a volume of

water and then put the object into the water to find its volume

(volume with object – volume without object). Calculate the

density by dividing the mass of the object by the volume of the

object. Complete the table below:

Object Mass

(g)

Initial

volume

(mL)

Final

volume

(mL)

Volume

Of object

(mL)

Density

(g/mL)

Answer the questions below:

1. What is the unit of density?

2. Which object has the highest density?

3. Which object/s sink in water?

4. Water has a density of 1.0 g/mL which can also be written as

1.0 gmL-1. Why do objects sink in water?

Activity 2.2 Density calculation practice

Calculate the densities of the objects below and answer the

questions:

Object Object

mass (g)

Volume

of object

(mL)

Density

of

object

(g/mL)

A 27 2

B 15 4

C 30 12

D 65 12

E 17 1

F 83 13

G 19 2

Questions:

1. Which object has the highest density?

2. Which object has the lowest density?

3. List the objects from highest to lowest density:

4. Which objects will float on water? (density of water is 1.0

g/mL)

5. Why are aluminium cans able to float on water when the

density of aluminium is 2.7 g/mL?

6. Fill in the table:

Volume of

water in

millilitres (mL)

Volume of

water in L

(litres)

Mass of

water in g

Mass of

water in kg

(kilograms)

6

75

120

500

2000

5500

10 000

Activity 2.3 Density in different liquids

Measure out 10 mL of water and 10 mL of glycerine in separate

measuring cylinders. Slowly pour the glycerine down the side of

the measuring cylinder containing water so that the glycerine

flows gently in. Place a small piece of Perspex in the top of the

measuring cylinder and record your observations.

Observations:

Inferences:

Activity 3.1 Observing diffusion in air/gases

Your teacher will use some kind of spray or perfume to

demonstrate diffusion. Record your observations and then explain

using particle theory why the smell eventually reaches the back of

the room.

Questions:

1. Would you expect smells to move faster on a hot or cold

day? Explain your answer.

2. Why do smells move faster around a room when there is a

fan going?

Activity 3.2 Observing diffusion in liquids

Your teacher will demonstrate diffusion in water using purple

potassium permanganate crystals and a straw in three different

beakers. One will be iced water, another will have room

temperature water from the tap and the last will have boiled water

in it.

Questions:

1. Record your observations: (take a photograph too)

Iced water Room temp water Boiling water

2. Why did your teacher use a straw to put the crystals down

the bottom of the beaker in each case?

3. In which beaker was the diffusion fastest? Explain using

particle theory why this is so.

4. What makes the purple colour spread?

Activity 4.2 Observing expansion and contraction in gases

Your teacher will demonstrate expansion of gases using a balloon,

some hot water and a tape measure.

Record your observations: (take a photograph)

Questions:

1. Why did the balloon expand?

2. Why do gases take the shape of their container?

3. Why did the balloon have to be held down in the water?

Activity 4.2 Observing expansion and contraction in liquids

1. Your teacher will demonstrate the expansion of water (with

purple colouring) in a round bottomed flask. He/she will

mark the water level on the neck of the flask before placing

the flask into a container with hot water.

Record your observations: (take a photograph)

2. Your teacher will demonstrate placing a gas jar with hot

purple water upside down on top of another gas jar with cold

clear water in it and sliding out the lid (carefully).

Record your observations: (take a photograph)

Questions:

1. Explain why the water level in the round bottomed flask

changed in terms of the energy of the water molecules and

what they are doing.

2. Explain your observations for the gas jar demonstration in

terms of the temperature and density of each liquid.

Activity 4.3 Observing expansion and contraction in solids

1. Your teacher will provide a ball and ring apparatus and

explain how to use it. You will be heating either the ball or

the ring strongly in a Bunsen flame and then trying to fit the

ball through the ring. After you have done this you will cool

the ball or ring under the tap and try again.

2. Your teacher will give you a bimetallic strip and ask you to

heat it in the Bunsen flame. After heating cool it under a tap.

Observations:

Before heating After heating

Observations:

Before heating After heating

Questions:

1. What caused the change you observed with the ball and

chain?

2. Did the particles themselves expand?

3. Describe the motion of the particles before and after heating.

4. Why did the bimetallic strip bend?

5. What could bimetallic strips be useful for?

Activity 5.1 Describing mixtures

A Pure Substance is made of just one kind of atom or molecule,

so it can be an element or a compound. You can write the

formula for a compound as it always has the same molecules.

A mixture is not a pure substance is as it is made of more than

one type or atom or molecule.

When you put salt into water you make a mixture. When a solid

dissolves in a liquid you get a solution. A solution is made of a

solute dissolved in a solvent.

Questions:

1. Write definitions for the words in bold above.

2. Label the boxes above with ‘element’, ‘compound’ or

‘mixture’.

3. Sometime solvents are used to dissolve solutes when they are

stains on clothes. Use the information in the table to decide

on what solvent you would use to remove ballpoint ink from

your shirt.

Solvent Nylon shirt Ball pen ink

Water insoluble insoluble

Toluene insoluble soluble

Methanol soluble soluble

Kerosene insoluble insoluble

4. Fill in the table:

5. A solution can be described as concentrated or dilute

depending on how much solute has been added. Circle the

most concentrated solution in each of the following

examples:

a. Coffee with one sugar/coffee with 3 sugars

b. Milo made with 4 spoonful/milo made with 1 spoonful

c. Dark tea/pale tea

6. Fill in the gaps:

a. Solutions that cannot dissolve any more solute are called

_________________.

b. If a mixture settles after standing a while it is a

_____________.

c. You can dissolve more ____________ in hot water than

you can in ___________ water.

d. If a mixture is not dissolved and the particles can settle

out we say that the particles are ________________ in

the liquid.

e. Two liquids that can be mixed are said to be

_______________.

Solute Solvent Solution

Sea water

Milo

Raro powder Raro drink

Washing powder

Black coffee

Flavouring Milk

f. Why two liquid form two layers when mixed we say

that they are _________________.

g. A solution with little solute dissolved is said to be

___________ whereas a solution with a lot of solute

dissolved is said to be _________________.

7. How do you tell the difference between a solution and a

suspension?

Activity 5.2 Observing solubility

Your teacher will give you some solids to try dissolving in water

and ethanol. Use small amounts and correct technique for mixing

(no finger over the top and shaking). Your teacher may give you

test tubes with stoppers.

Fill in the table with your observations:

Solid Soluble in

water?

Observations

Flour

Sugar

Salt

Copper sulfate

Coffee

Solid Soluble in

ethanol?

Observations

Flour

Sugar

Salt

Copper sulfate

Coffee

Questions:

1. What solids were soluble in water?

2. What solids are soluble in ethanol?

3. What happened to the insoluble solids? Describe them.

Activity 5.3 Observing and describing suspensions

Blow through a straw into limewater and it goes cloudy. It is

cloudy because the white solid calcium carbonate is being made.

Calcium carbonate is not soluble (it does not dissolve) it is just

suspended in the water. If you leave it long enough you will see a

white solid on the bottom. The same happens to muddy water.

Practical: Your teacher will give you some muddy water. In your

group decide how you could separate the mud from the water.

Check with your teacher and then use the equipment provided to

separate the mud from the water. Insert a photograph showing

your method below:

Questions:

1. Did your method work? Explain your answer.

2. How could you describe the mixture or mud and water?

3. Describe another method of separating this mixture.

Activity 6.1 Separating Techniques: Decanting

Questions:

1. How effective was this method for separating sand and

water? Explain your answer.

2. What other mixtures could you separate using this method?

3. Draw a scientific diagram of decanting and photograph it.

Insert it here:

You will be given a shaken mixture of sand

and water. Using a stirring rod across the top

of a beaker, carefully pour the water off the

sand.

Activity 6.2 Separating Techniques: Filtration

Questions:

1. How effective was this method for separating chalk

dust/silt/mud and water? Explain.

2. What other mixtures could you separate using this method?

3. Would it be possible to filter sea water (to get the salt out)

using this method? Explain your answer.

4. Draw a scientific diagram of filtration (label filtrate and

residue) and photograph it. Insert it here:

You will be given a mixture of sawdust and water or water with silt/mud in it. Using a filter funnel and filter paper filter the mixture. You teacher will show you how to fold the filter paper.

Activity 6.3 Separating Techniques: Centrifuging

Questions:

1. Explain in your own words how a centrifuge works.

2. A washing machine is a centrifuge. Explain this statement.

3. Centrifuges only work on a special type of mixture. Explain

with examples what this means.

A centrifuge is used to speed up sedimentation in suspensions.

Your teacher will show you a centrifuge and explain how it works.

Activity 6.4 Separating Techniques:

Evaporation or Crystalisation

Questions:

1. How effective was this method for separating the solution?

Explain your answer.

2. Where has the liquid gone?

3. Take a photograph of your evaporating dish after you have

finished heating and insert it here:

4. What other mixtures could you separate using this method?

5. Draw a scientific diagram of evaporating and photograph it.

Insert it here:

You will be given a copper sulfate solution.

Set up a Bunsen burner on a baseboard and

heat a small volume of the solution over the

Bunsen using an evaporating dish, tripod

(and gauze if needed). WEAR SAFTEY

GLASSES. *It may spit towards the end

Activity 6.5 Separating Techniques: Distillation

Questions:

1. How effective was this method for separating the solution?

Explain your answer.

2. Where has the liquid gone?

3. Where has the solute gone?

4. Explain why the distillate is not purple.

5. Take a photograph of your distillate after you have finished

heating and insert it here:

6. What other mixtures could you separate using this method?

7. Draw a scientific diagram of distillation and photograph it.

Insert it here:

You will be given a potassium

permanganate solution. Set up a Bunsen

burner on a baseboard and heat a small

volume of the solution over the Bunsen

using a conical flask with delivery tube,

tripod and gauze. Catch the distillate in

another conical flask as shown in the

photo. WEAR SAFETY GLASSES.

Activity 6.6 Separating Techniques: Magnetic Separation

Questions:

1. Describe how magnetic separation is used in industry.

2. What metals are magnetic?

Activity 6.7 Separating Techniques: Chromatography

Questions:

1. Take a photograph of your chromatography starting and

finishing. Insert the photographs here:

2. What colour did you start with and what colours did you see

at the end?

3. What other mixtures could you separate using this method?

Use a magnet to separate the sand from the

iron filings but be very careful not to get

iron filings on the magnet (or you will

spend your lunchtime picking them off!)

Follow your teacher’s instructions and set

up your chromatography as shown in the

photo.

Activity 6.8 Separating Techniques: Revision Questions

1. Name the separation techniques that you would use to

separate these mixtures:

a. blood

b. peas in water

c. sea water to get the salt

d. sea water to get the water

e. colours in beetroot juice

f. chalk dust in water

g. iron nails from sawdust

2. Describe how you would separate a mixture of salt, sand and

sawdust. Explain all steps and name what is separated in

each step.

3. Describe how you could get fresh water from seawater if you

were on a deserted island. You have access to fire.

4. Use the following words to fill in the blanks:

Gases, kinetic, constant, liquids, solids, close,

temperature, average, volume, expand, past, particles,

tightly, vibrate, fast, faster, energy.

_________________ in all substances are in

_________________ motion. In _______________ the

particles are _______________ packed together and can only

________________. In _________________ the particles are

close together but can move _____________ each other. In

____________ the particles are far apart and move very

_________.

When you heat a substance the particles gain ____________

energy and moves ______________ or vibrate more

vigorously.

_________________ is a measure of the ______________

kinetic ____________. Heating solids (especially metal)

causes them to ____________ because the particles tend to

vibrate a lot. In gases the particles move faster and further

apart when heated so their ______________ increases.

Solutions: Use these words to fill the gaps: solvent, evaporate,

dilute, miscible, immiscible, solute, saturated, concentrated,

unsaturated.

A solution is a (usually solid) dissolved in a

(liquid)

A solution is when not much solute is dissolved and

when a lot of solute is dissolved.

A solution cannot dissolve any more solute but an

solution can dissolve more solute.

Two liquids are if they mix and if they form layers

If you want the solute back you need to the liquid to

crystallise the solute.

Suspensions : Use these words for the gaps: centrifuge, faster,

sediment, filter, suspension.

An insoluble solid shaken in a liquid forms a . It

looks cloudy or milky at first, but as you watch it clears and the

particles settle to the bottom forming a . So a

suspension does not dissolve and eventually settles.

Suspensions are not transparent (you cannot see through them)

A centrifuge helps suspensions settle

You can a suspension.

Chromatography and Evaporation : Use these words to fill in the

gaps: smallest, bigger, evaporation, chromatography.

The process called is used to separate

large and small molecules by running a solvent through a

mixture.

Colours in ink can be separated by chromatography. The

__

molecules travel the most and the molecules don’t.

The process of is heating a solution so that

the liquid evaporates leaving crystals

Activity 6.9 Heads and Tails

Match the heads with the correct tails by putting the correct

number in the first column.

COMPRESSIBLE 1 An explanation of what is happening

CONDENSATION 2 Becoming larger due particles vibrating

more

CONTRACTION 3 Becoming smaller on cooling

DENSITY 4 Mass divided by volume

DIFFUSION 5 Particles are able to be pushed closer

together

EVAPORATION 6 Phase change

EXPANSION 7 Phase change gas to liquid

FREEZING 8 Phase change gas to solid

GAS 9 Phase change liquid to gas

INFERENCE 10 Phase change liquid to solid

LIQUID 11 Phase change solid to gas

MASS 12 Stat of matter where particles are close

together but can move

MATTER 13 State of matter where particles are held

in position

MELTING 14 State of matter with particles far apart

and moving fast

OBSERVATION 15 Takes up space and has mass

REVERSE

SUBLIMATION

16 The amount of matter in an object.

Unit : kg

SOLID 17 What can be seen, heard, smelt, felt or

tasted

SUBLIMATION 18 When a substance spreads slowly

through a liquid or gas

Activity 6.10 Crossword

Matter Mixing and Separating Across

1 made of one type of molecule

7 crystallisation

9 made of one type of atom

10 what goes through the filter

13 two liquids can mix

14 liquids form two layers

15 evaporating and condensing Down

2 describes a solution that can dissolve more solute

3 a solution that cannot dissolve any more solute

4 in raro the solute is the ___________

5 solute + solvent mixed

6 in raro the solvent is _________

8 what is caught on the filter

11 what is mixed into the solvent

12 the liquid that the solute is dissolved in

Extension Extension activities

1. Explain what is happening to the particles where the graph is

red:

2. Fill in the Venn diagram:

Solid Gas

Liquid

3. Explain the phase changes in the diagram and explain how

you could use distillation to get fresh water from seawater.

4. Explain in detail how the particles behave as a metal rod is

heated and then cooled again:

5. What makes a bimetallic strip useful in electrical circuits?

6. Explain how this thermometer works:

7. Explain why power lines sag on hot days and are less saggy

on winter days.

8. Explain why diffusion occurs only in liquids and gases.

9. Label the hottest and coldest beakers below and explain what

causes the difference in diffusion rate.

10. In chromatography the colours move at different rates.

Explain what makes the colours spread out.

11. Explain how a vacuum cleaner works using the terms

filter, filtrate and residue.

12. Describe how you would separate a mixture of salt, sand

and sawdust. Explain all steps and name what is separated

in each step.