Year 7 Separating mixtures

Key Concepts



  1. 1. Solutions
  2. 2. Suspensions
  3. 3. Separating mixtures
  4. 4. Separating solutions
  5. 5. Separation in industry
NAME:

Pre-Test http://www.classroomclipboard.com/490625/Test/54318A6ED14D419AB5E284CD8BDCA4CB

Access code: 236K8

Science Quest 7
TEXTBOOK for staff reference
SCIENCE Quest 7 PRACTICALS / ACTIVITIES
SCIENCE Quest 7
HOMEWORK
OTHER ACTIVITIES/RESOURCES
1
5.1 What’s in a fizzy drink p.168
Investigation 5.2 Soluble in water? (Worksheet 5.1)

Investigation 5.3 Froth & bubble
Worksheet: solutions mix & match
introduction to separations

http://www.bbc.co.uk/education/clips/zb9c87h

Solution solvent and solute
https://www.youtube.com/watch?v=e-2EoyDYamg
Words to Learn
Dissolved, solution, solute, solvent, aqueous solutions, soluble, insoluble, concentrated, saturated, dilute
2
5.2 Kept in suspension p.171
Investigation 5.4: Filtration in the laboratory

Investigation 5.5: Making a simple water still

Worksheet: types of mixtures
Worksheet: separating mixtures mix and match
Pure and impure mixtures and separating

https://www.youtube.com/watch?v=nqc9ASP0tq0
Words to Learn
Suspension, sediment, filtration, colloid, emulsion, filtrate, residue, decanting, sieving, separating funnel, centrifuging,
3
5.4 Separating Solutions p.176

http://www.gcsescience.com/e1-element-compound-mixture.htm
Investigation 5.1 Design & separate (magnetic separation)

Investigation 5.6: Separating colours

Investigation 5.7: Crystallisation and distillation (Worksheet 5.5)

Demonstration: centrifuge

Worksheet: Methods of separation video task.

Worksheet 5.6: concept map
Worksheet 5.2: mailroom mayhem
Worksheet 5.3: the pool shop
Worksheet 5.4: heating and distillation

COMMON ASSESSMENT TASK - Experimental Design
Washing detergent task

Mixtures Lab Animation: http://www.harcourtschool.com/activity/mixture/mixture.html

Activity: Design a mixture that can be separated using as many as possible of the methods you have seen in this chapter. List the components of the mixture and challenge another student to find a step-by-step method of separation. Be sure to include answers.
e-lesson: centrifuge
e-lesson: distillation

Words to Learn
Distillation, evaporation, water condenser, condensation, distillate, distilled water, crystallisation, sustainable, chromatography
4
SCIENCE AS A HUMAN ENDEAVOUR
5.2 Separating Blood p. 174
5.3 Systems: Down the S Bend p.181
5.6 Fit to Drink p.183
5.7 Essential Separation p.185
5.8 Essential Recycling p. 188
Investigation 5.8: treating your own dirty water
Investigation 5.9: Separation by flotation
COMMON ASSESSMENT TASK: Science as a Human Endeavour

Worksheet 5.7: clean & clear
e-lesson: treating sewerage

Covered by student choice research task
5
Revision
Test
Worksheet 5.8: separation techniques
Worksheet 5.9: mind maps and flow charts
Worksheet 5.10: fill in the gaps
Worksheet 5.11: crossword
Worksheet 5.12: fill in the gaps










Class notes

Pure and Impure

A pure substance is made of one type of particle
An example of a pure substance is water

An impure substance is made of many types of particles
An example of an impure substance is dirt
Mixtures can be made of impure and pure substances mixed together.

Separating

( means to Divide into groups based on their properties)

We can separate a mixture back into its component parts if we know some of the components properties. For example we can separate iron pins from sand easily because we know iron is magnetic and sand is not. So we can use a magnet to attract the pins away form the sand.

Some other properties we can use are:
  • if a salt is dissolved in water we can evaporate the water leaving the salt
  • if dirt is in water we can filter out the dirt and leave the water
  • if oil is mixed with water we can let the oil settle on the surface and decant (tip) the oil off.



  • Testing for Solubility
  • When something dissolves in a liquid we say it is soluble. The liquid it dissolves in is called the solvent and the stuff that dissolves is called the solute.
  • If a solute does not dissolve in the solvent it is said to be insoluble.

  • Results of the experiment Testing for solubility

Substance to dissolve
Solute
Solvent
Observations
Sand
Water
Insoluble, sinks
Tea
Water
Partially soluble – turns water brown
Sugar
Water
Soluble, makes a sugar solution. Needed lots of stirring to dissolve completely
Salt
Water
Soluble
Copper carbonate
Water
Sinsoluble
Flour
Water
Insoluble

Copper Sulfate

Water

Soluble


Solubility Terms
When something dissolves in a liquid we say it is soluble. The liquid it dissolves in is called the solvent and the stuff that dissolves is called the solute.
If a solute does not dissolve in the solvent it is said to be insoluble.

Solute + Solvent --------> solution



What affects solubility
Temperature - the experiment where we heated the water in
a test tube and added copper sulfate showed us that we could
keep adding copper sulfate while the temperature of the water was high.

Surface area – If we increase the surface area of the solute by crushing it
it will dissolve faster.

Concentration.
If we have lots of a solute in a solution its called concentrated. If there is not much its dilute.

Suspensions
When a substance does not dissolves but floats in the solvent its called a suspension. Eventually it will settle to the bottom of the flask. Then its called a sediment.

Colloids
Are tiny insoluble particles that never settle as sediment. Examples are paint,

Filtration in the laboratory
Aim: to make a filtering cone out of filter paper and separate a mixture.
Method
Half fill your 100 mL beaker with water.
Add your insoluble substance to the water and stir with the stirring rod.up the equipment for filtering as shown in the top diagram in Sift and separate.
Fold filter paper into a fluted filter cone
Place the filter paper in the funnel and moisten with clean water to hold the filter paper in place.
Pour your mixture into the filter paper.

Results
What did you observe? yellow before we added it to water, When we added it to water it looked a bit green,
After we filtered it the yellow residue stuck to the filter paper while the blue filtrate was collected in the conical flask.

  • Filtration 5-2_source2.jpg
    Filtration in 3D from Dimensions yr7







  • Discussion
  • Describe the appearance of your mixture in the beaker before filtration. Did it form a suspension or sediment, or float on top? Formed a suspension and a sediment.
  • The liquid passing through the filter into the conical flask is called the filtrate. Describe your filtrate. The FIltrate was Green or blue in colour but we can see through it.
  • Examine your filter paper. The material trapped by the filter paper is called the residue. Describe your residue. The residue was yellow
  • Filter paper is like a sieve with small holes in it. Explain how the filter paper worked like a sieve in this experiment. The holes in the filter paper were smaller than the lumps of chalk that got stuck on the filter paper but big enough to let the water and copper sulfate pass through.



  • Separating techniques
  • You can separate solids from mixtures by using a range of techniques. To do the separating you need to know the properties of the substances in the mixture. Choose a property that is different to any others in the mixture and then choose a technique that will allow you to separate the solids
  • Example 1
  • Separating sand and iron filings

  • The properties of these are
  • || Properties of sand || Properties of iron filings ||
    || Does not dissolve in water || Does not dissolve in water ||
    || Sinks in water || Sink in water ||
    || Not magnetic || magnetic ||

  • So to separate these 2 we will use irons magnetic properties because sand is not magnetic.
  • Picture of how you did this.

Separating using density
Density is a property of a substance which describes how tight the particles (atoms) in a substance are packed.
Particles in foam are not tightly packed while particles in steel are tightly packed. It is also true that objects of the same size can have different weights (or mass) the heavier object will have the greatest density.
The following techniques separate components of a mixture because each component has a different density.

Using a centrifuge to separate substances
Substances with a greater density will separate out of solution that is spun at high speed before the lighter particles will settle. This method is used to separate red blood cells out of blood plasma.
Try this: muddy water in a bucket and spin it around- what happens?
Draw a picture.

Using a separating funnel
this is used to separate liquids of different densities. The tap at the bottom of the funnel can be opened to allow the most dense liquid to drain out.
Draw a picture of this device.

Separating solutions In a mixture

Chromatography.This can be used to separate the colour inks in a pen. It works because the different colours have a different weight. The lightest ones travel the furthest up the filter paper.
Paste in your results.



Distillation

This will separate different solutions if they have a different boiling point. Eg separating alcohol, from water. Copy the picture below
DistiallationCondensorFUnction.jpg

The distillation apparatus works because water boils at 100 degrees C. The liquid water is heated so it changes state from a liquid to a gas. The water gas is passed along a cooling tube – called the condenser. The condenser is a glass tube inside a glass tube. This forms a sleeve. Cold water is passed around the sleeve. In the condenser the water changes state back to a liquid. This liquid is now collected in a container.
On your diagram mark the direction the water flows.




Collecting water in the desert.We made a bush still by collecting leaves and putting it inside a closed container. We hope the water will evaporate out of the leaves and become a gas. The gas should cool down on the underside of the plastic and water should run into our collecting jar.
Draw a picture of our bush still


Absorption

Absorption is a separating technique that relies on one of the substances being able to be absorbed into something like a sponge or kitchen paper.
When you buy meat the packaging some times has a small sponge like pad that sits below the meat to separate the meat from meat juice and blood. It does this by soaking up the blood.
Describe example of absorption;


Froth flotation


  • Some times chemicals or ores will stick to bubbles of detergent or froth. because this floats we can use collect the froth along with the chemical using a scoop. They use this technique in mining copper where they separate the copper ore from the surrounding rock after all the rock is crushed.

  • Floculants or floculation.
  • This is a method to make a suspension clump together so its easy to pick up the bigger bits. You may use this to clean up the water in your pool. If the water is cloudy or murky or muddy you can use a flocculant whihc will make the bits clump. They then fall to the bottom of the pool and you can vacuum them up.
  • floculant index.jpg
    The muddy water is now clear because a flocculant made the mud clump and fall to the bottom of the beaker

  • Floculation 2 index.jpg


Distillation



Revision for this topic
Go to the cloze word passage to do some revision

More revision














|||||| Key Concepts || |||| ||
  • ||||||||
Liquid solutions
Soluble and insoluble
Suspensions and emulsions
Different separating techniques
Water treatment
Recycling
NAME:
  • || || Science Quest
TEXTBOOK |||| SCIENCE Quest PRACTICALS / ACTIVITIES || SCIENCE Quest
HOMEWORK /WORKSHEETS || OTHER ACTIVITIES/RESOURCES ||

  • 1

5 Separating mixtures

page 180
Your Quest
Separating mixtures
INQUIRY: INVESTIGATION 5.1
Design and separate

Assesson
Readiness Test
Chapter 5

  • 2

5.1 What’s in a fizzy drink?

page 182
INQUIRY: INVESTIGATION 5.2
Soluble in water?
INQUIRY: INVESTIGATION 5.3
Froth and bubble
Risk Assessment
5.2 Soluble in water?
Worksheet found in Jacplus
5.1 Soluble or insoluble?
5.2 Mail room mayhem
  • Assesson
Progress Test 5.1
Homework

  • 3

5.2 Kept in suspension

page 185
INQUIRY: INVESTIGATION 5.4
Filtration in the laboratory

Identify which commonly used mixtures can be separated by the process of filtration by completing the Filtration interactivity in your eBookPLUS.
int-0223
eLesson
Centrifuging
Learn how to separate a solid from a liquid using a centrifuge. eles-0061
Interactivities
Classify a series of liquid mixtures as suspensions, solutions or emulsions by completing the Time Out: ‘Mixtures’ interactivity in your eBookPLUS. int-0224

Questions from text book p 187 Ques 1, 3, 5

Ques from text book p 193 Ques 2, 3,
  • Worksheet found in Jacplus
5.3 The pool shop

Assesson

Progress Test 5.2
Homework

  • 4

5.3 Separating blood

page 188
INQUIRY: INVESTIGATION 5.5
Using a centrifuge (teacher demonstration)
Risk Assessment
5.5 Using a centrifuge
Assesson

Progress Test 5.3

  • 5

5.4 Separating solutions

page 190
INQUIRY: INVESTIGATION 5.6
Making a simple water still

INQUIRY: INVESTIGATION 5.7
Separating colours
eLesson
Distillation
Watch a scientist guide you through the process of distillation, which can be used to turn salty water into pure water. eles-0060
Assesson

5.4 Heating and distillation
5.5 Crystallisation and distillation

Assesson

Progress Test 5.4
Homework

  • 6

5.5 Systems: Down the S-bend

page 194

5.6 Fit to drink? page 197
eLesson

Treating sewage
Watch this video lesson to learn about water and sewage treatment and the use of recycled water in Australia.
eles-0059
eles-0059

eles-0059

INQUIRY: INVESTIGATION 5.8
Treating your own dirty water
  • Worksheet found in Jacplus
5.6 What do you know?
Risk Assessment
5.8 Treating your own dirty water

Worksheet found in Jacplus
5.7 Clean and clear?
ProjectsPLUS
The diamond flush
Investigate how sewage that leaves the house is processed, in particular the way in which separation methods are employed at different stages. **pro-0070**

  • 7

5.7 Separation in industry

page 199
5.8 Essential recycling
page 202
INQUIRY: INVESTIGATION 5.9
Separation by flotation
  • Worksheet found in Jacplus
5.8 Separation techniques
Assesson

Progress Test 5.7
Homework
Progress Test 5.8
Homework

  • 8

Looking back
page 207
  • Worksheet found in Jacplus
5.10 Summing up
5.11 Looking back: Separating mixtures
5.12 Science literacyTestmaker
Answers to chapter questions

Assesson

Achievement Practice test
Chapter 5
Achievement Test
Chapter 5 (Teacher Set)

















  • Class notes
  • Separating
  • Divide into groups


  • Testing for Solubility
  • When something dissolves in a liquid we say it is soluble. The liquid it dissolves in is called the solvent and the stuff that dissolves is called the solute.
  • If a solute does not dissolve in the solvent it is said to be insoluble.

  • Results of the experiment
*
Substance to dissolve
  • Solute
Solvent
Observations
  • || Sand || Water || Insoluble, sinks ||
  • || Tea || Water || Partially soluble – turns water brown ||
  • || Sugar || Water || Soluble, makes a sugar solution. Needed lots of stirring to dissolve completely ||
  • || Salt || Water || Soluble ||
  • || Sodium bicarbonate || Water || Soluble ||
  • || Flour || Water || Insoluble ||

  • Solubility Terms
  • When something dissolves in a liquid we say it is soluble. The liquid it dissolves in is called the solvent and the stuff that dissolves is called the solute.
  • If a solute does not dissolve in the solvent it is said to be insoluble.

  • What affects solubility
  • Temperature - the experiment where we heated the water in
  • a test tube and added copper sulfate showed us that we could
  • keep adding copper sulfate while the temperature of the water was high.

  • Surface area – If we increase the surface area of the solute by crushing it
  • it will dissolve faster.

  • Concentration.
  • If we have lots of a solute in a solution its called concentrated. If there is not much its dilute.

  • Suspensions
  • When a substance does not dissolves but floats in the solvent its called a suspension. Eventually it will settle to the bottom of the flask. Then its called a sediment.

  • Colloids
  • Are tiny insoluble particles that never settle as sediment. Examples are paint,

  • Filtration in the laboratory
  • Aim: to make a filtering cone out of filter paper and separate a mixture.
  • Method
  • Half fill your 100 mL beaker with water.
  • Add your insoluble substance to the water and stir with the stirring rod.
    • up the equipment for filtering as shown in the top diagram in Sift and separate.
    • Fold filter paper into a fluted filter cone
    • Place the filter paper in the funnel and moisten with clean water to hold the filter paper in place.
    • Pour your mixture into the filter paper.

  • Results
  • What did you observe? yellow before we added it to water, When we added it to water it looked a bit green,
  • After we filtered it the yellow residue stuck to the filter paper while the blue filtrate was collected in the conical flask.

  • Filtration 5-2_source2.jpg
    Filtration in 3D from Dimensions yr7







  • Discussion
  • Describe the appearance of your mixture in the beaker before filtration. Did it form a suspension or sediment, or float on top? Formed a suspension and a sediment.
  • The liquid passing through the filter into the conical flask is called the filtrate. Describe your filtrate. The FIltrate was Green or blue in colour but we can see through it.
  • Examine your filter paper. The material trapped by the filter paper is called the residue. Describe your residue. The residue was yellow
  • Filter paper is like a sieve with small holes in it. Explain how the filter paper worked like a sieve in this experiment. The holes in the filter paper were smaller than the lumps of chalk that got stuck on the filter paper but big enough to let the water and copper sulfate pass through.



  • Separating techniques
  • You can separate solids from mixtures by using a range of techniques. To do the separating you need to know the properties of the substances in the mixture. Choose a property that is different to any others in the mixture and then choose a technique that will allow you to separate the solids
  • Example 1
  • Separating sand and iron filings

  • The properties of these are
  • || Properties of sand || Properties of iron filings ||
    || Does not dissolve in water || Does not dissolve in water ||
    || Sinks in water || Sink in water ||
    || Not magnetic || magnetic ||

  • So to separate these 2 we will use irons magnetic properties because sand is not magnetic.
  • Picture of how you did this.


  • Using a centrifuge to separate substances

  • Substances with a greater mass will separate out of solution that is spun at high speed before the lighter particles will settle. This method is used to separate red blood cells out of blood plasma.



  • Try this: muddy water in a bucket and spin it around- what happens?

  • Draw a picture.



  • Separating solutions In a mixture

  • Chromatography.
    • This can be used to separate the colour inks in a pen. It works because the different colours have a different weight. The lightest ones travel the furthest up the filter paper.
    • Paste in your results.



  • Distillation
    • This will separate different solutions if they have a different boiling point. Eg separating alcohol, from water. Copy the picture (fig 3.3.2) on page 76 of the text
    • The distillation apparatus works because water boils at 100 degrees C. The liquid water is heated so it changes state from a liquid to a gas. The water gas is passed along a cooling tube – called the condenser. The condensor is a glass tube inside a glass tube. This forms a sleeve. Cold water is passed around the sleeve. In the condenser the water changes state back to a liquid. This liquid is now collected in a container.


  • Collecting water in the desert.
    • We made a bush still by collecting leaves and putting it inside a closed container. We hope the water will evaporate out of the leaves and become a gas. The gas should cool down on the underside of the plastic and water should run into our collecting jar.
    • Draw a picture of our bush still


  • Absorption
    • Absorption is a separating technique that relies on one of the substances being able to be absorbed into something like a sponge or kitchen paper.
    • When you buy meat the packaging some times has a small sponge like pad that sits below the meat to separate the meat from meat juice and blood. It does this by soaking up the blood.
    • Describe example of absorption;
  • Froth flotation


    Some times chemicals or ores will stick to bubbles of detergent or froth. because this floats we can use collect the froth along with the chemical using a scoop. They use this technique in mining copper where they separeate the copper ore from teh surrounding rock after all the rock is crushed.

    Floculants or floculation.
    This is a method to make a suspension clump together so its easy to pick up the bigger bits. You may use this to clean up the water in your pool. If the water is cloudy or murky or muddy you can use a flocculant whihc will make the bits clump. They then fall to the bottom of the pool and you can vacuum them up.

    floculant index.jpg
    The muddy water is now clear because a flocculant made the mud clump and fall to the bottom of the beaker


    Floculation 2 index.jpg





  • Revision for this topic
  • Go to the cloze word passage to do some revision

  • More revision