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MAKING CLEAR

SOUP

INVESTIGATING

SOLUBILITY

5-14 Environmental Studies, Science,

Levels E and F

National Curriculum, Key Stage 3

MAKING CLEAR SOUP

Investigating Solubility

5-14 Environmental Studies, Science, Levels E and F Page

National Curriculum, Key Stage 3 1

Secondary:

Making Clear Soup. Investigating solubility:

This web based resource is written for 5-14 Environmental Studies, Science,

Levels E and F in Scotland and for the National; Curriculum, Key Stage 3, in

England and Wales. It includes many practical activities and background

information for these levels. There are Teacher, Technician and Pupil

sheets available. All the activities are freely available via the SAPS web

site: saps.org.uk

MAKING CLEAR SOUP




Acknowledgements:

The authors, Pam Ferguson and Marjorie Smith, would like to thank the

following for their involvement with this work.

ICI, in particular, Jane Gamble, formerly Education Officer

for ICI.

SAPS, Science and Plants for Schools

(http://www.saps.org.uk/)

Dollar Academy, particularly Cameron Smith of the Chemistry

Department and his classes, for allowing us to trial the topics.

(http://www.dollaracademy.org.uk/)

http://www.saps.org.uk/

http://www.dollaracademy.org.uk/

MAKING CLEAR SOUP




CONTENTS

Introduction to Soups and Solutions.

Investigation work on salt solutions with follow up questions

Examination of prepared packets of soups. Analysis of ingredients.

Alternative investigation into dissolving.

Solutions, suspensions and colloidal dispersions with an investigation into

the properties of colloidal dispersions and solutions.

Factors affecting the rate of dissolving.

Background information for group work on rate of dissolving.

Workcard 1: The Temperature of the Water.

Workcard 2: The Amount of the Solute.

Workcard 3: Stirring and how much Stirring?

Workcard 4: The Volume of the Water Used.

Workcard 5: The Particle Size.

Workcard 6: Pupil defined factor.

Teacher Supplementary Notes: Alternative route for investigating

solubility.

Investigation to test the hypothesis that: The time required to cause a

change in temperature increases as the amount of material dissolved in

the water increases. The more the dissolved substance the less the

rise in temperature.

Examining the concept of controls in experiments.

Further related investigations and identifying variables.

Pupil booklet

Technical Guide: Materials and equipment for the learning and assessing

activities.

Glossary

MAKING CLEAR SOUP




Making Clear Soup

Introduction to Soups and Solutions:

Many people like soup, especially when the days are cold and dark. In our

country more people prefer hearty, thick, creamy soups. In other countries

a clear soup is often the favourite. Soups are meant to stimulate the

appetite and get our digestion ready for the main course. A clear chicken

noodle soup is sometimes used to feed a sick person and some research

suggests that there may be ingredients in such a soup that helps to heal a

person suffering from a cold.

Your challenge is to help to design a soup that will satisfy the European

market for clear soup. You are going to look at many of the variables

involved in such a design. You will have to think about what ingredients could

go into the soup. If you have to keep it clear, you will need to look at

ingredients that dissolve into a solution.

What does dissolve mean? What does solution mean?

When you add a spoonful of sugar to a cup of hot tea, it

dissolves and forms a sweet solution. This means the

sugar appears to dissappear from view. However, it is still

there because when you taste the tea, it tastes sweet.

A substance which dissolves to make a solution is said to

be soluble. A substance which does not dissolve is said to

be insoluble (e.g. sand). The substance which is dissolved

is called the solute ( e.g. sugar in this case). And the substance which does

the dissolving is called the solvent, (e.g. the hot water in the tea). Water is

the commonest solvent but there are many others, ( e.g. ethanol, hexane).

MAKING CLEAR SOUP




Investigation work on salt solutions with follow up

questions.

How much salt will dissolve in 50 ml water?

Materials

Graduated cylinder

Beaker

Water

Salt ( about 25g on a small piece of

paper)

Stirring rod

Spatula

Balance

Method

Prepare a table in your notebook like this:

Mass of salt and paper before

dissolving

g

Mass of salt and paper when no more

salt dissolves

g

Mass of salt that dissolved in 50 ml

water

g

Find the mass of the salt and paper, and record the mass in your table.

Measure 50 ml water into the graduated cylinder and then pour it into

the beaker.

Using the spatula, place a small amount of salt into the water and using

the stirring rod, stir to dissolve.

When the salt has completely dissolved, continue

adding a small quantity of salt, stirring until

dissolved. Look for traces of undissolved salt in

the water. Eventually you will find that the salt

in the bottom will not dissolve, no matter how

much you continue to stir it.

When no more salt will dissolve, measure the

mass of the salt that remains on the paper.

Record this amount.

Calculate the mass of the salt that dissolved.

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Questions:

1. Was there a limit to how much solute would dissolve?

2. How much salt dissolved in the 50 ml of water?

3. Try to explain why there might be a limit to how much solute will dissolve

in a solvent.

4. Did every group in the class get the same value? If not, why not?

5. Was this investigation a fair test?

MAKING CLEAR SOUP




If we examine some ready prepared packets of soup we will get some ideas

about their contents.

Investigation:

What is in a packet of soup?

Each group will examine a packet of dried soup

mix.

Construct a table of the main contents found in

those packets examined. Each group to tabulate

their first six main ingredients from their

assigned packet. Pupils should note that

ingredients are listed in order of greatest quantity to least. The

completed table should reflect this.

A table could look like this:

Table to show the first six main ingredients in Minestrone soup.

ingredients

%

Dried

noodles

Dehydrated

vegetables

Potato

starch salt

Tomato

powder sugar

18.5 17.5 N.A. N.A. N.A. N.A.

N.A. = (% content) Not Available

Construct a bar graph of the most common ingredients, found in your

class survey of packet soups.

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Your research may show that the main ones are salt, potato starch and

sugar. Your first investigations will look at the variables involved in the

dissolving of salt, potato starch and sugar.

Can you make any predictions about the dissolving of salt, potato starch or sugar? You will notice that the packets of soup you have

examined must be ready in a relatively short time. You

may only have about five minutes from putting it into the

pan to serving the soup. Your ingredients have only this

time to dissolve.

How do the recommended cooking times given on the packets vary throughout the class? You will also notice that the instructions on the packet refer to stirring.

Some instructions say to use a whisk or fork rather than a spoon.

Can you think why a whisk or fork is better for stirring dried soup in water than a spoon?

MAKING CLEAR SOUP




Alternative investigation into dissolving:

What do we understand by the word dissolve?

We are going to conduct an investigation to see if the mass of salt affects

how fast the salt dissolves in the water. Using the same volume and

temperature of water, four different masses of salt ( e.g. 10, 20, 30, 40 ml,

use a measuring cylinder for this) will be stirred until no more crystals are

visible. Each mass of salt will be tested three times.

A table for results:

Amount of

salt (ml)

Time to dissolve ( min) Average time

to dissolve

(min)

Trials

1 2 3

10

20

30

40

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So far we have looked at salt dissolving in water. A clear, colourless

solution results from this.

If we take cornflour and try to dissolve it in water we get a cloudy mixture.

See what happens when you take a dry test tube and add a spatula of

cornflour. Then, add room temperature water half way up the test tube.

Shake the test tube and observe. Write down your observations in the table

below.

Let the test tube rest in a test tube rack for some minutes. You may leave

the test tubes overnight.

Record your observations.

Time ( minutes ) Observations

At start, cornflower just added and

shaken

1 minute

2 minutes

(overnight, optional)

You should have noticed that the test tube of cornflour and water was not

clear. The particles of cornflour were suspended in the water,for a while at

least. The suspension was cloudy. Solutions and suspensions are two

extremes of mixtures. In one the particle is very large. In the other, a

particle is very small. There is something in between and it is called a

colloidal dispersion.

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Solutions, Suspensions and Colloical Dispersions

Investigation: Observing the Properties of Colloidal Dispersions and

Solutions.

Materials:

2 250 ml beakers

powdered gelatine

sodium chloride

light beam source

Method:

Stir 4 g sodium chloride (table salt) into some very hot water in a beaker.

Does it dissolve?

Stir 4 g gelatine into some very hot water in a beaker. Does it seem to

dissolve?

Keep stirring. If some gelatine remains after a lot of stirring, try again

with less gelatine or hotter water.

Examine the beaker. Can you see any difference in it from a beaker of

salt solution?

Shine a narrow beam of light through the beaker. Compare the effect

with the effect of shining the same beam through a salt solution.

MAKING CLEAR SOUP




You may have seen an effect like this before. On a clear night, the light

beam from the car’s headlights is barely visible. On a foggy night the beam

is quite visible.

How do you account for this difference?

The particles of gelatine in a colloidal dispersion are called the dispersed

phase. They are like the solute of a solution. The water is called the

dispersing phase. It is like the solvent of the solution. A colloidal dispersion

has certain characteristics. It will scatter a beam of light. It will pass

unchanged through filter paper. Its particles, the dispersed phase, are

visible under a microscope. These characteristics tell us that the particles

of the dispersed phase are small enough to pass through filter paper but

large enough to reflect light. The reflecting of light by colloidal particles is

called the Tyndall effect.

Colloidal particles have unique properties due to their size. They expose

large surface areas and are useful in absorbing poisonous gases, dyes and

other materials.

Why might they be of great importance to our soup design?

Think about flavour and texture. You may have already

explored viscosity in another topic. The dispersal of the

flavouring molecules will be of much importance to the

soup designers.

Colloidal dispersions are not only solids dispersed in

liquids. A solid, liquid or gas may be the dispersed phase

or the dispersing phase. Other examples of colloidal

substances are starch dispersed in water, foam, jellies,

smoke, fog, cell contents of animal tissues, many foods,

drugs and plastics.

MAKING CLEAR SOUP




Factors affecting the rate of dissolving

So we have had a look at what is actually in the soup and what sort of state

these substances are. Now we will look at the rate of dissolving.

How can we get the contents to dissolve quickly?

Remember some soups are supposed to be ready in 3 minutes.

What factors will affect the rate of dissolving?

Here are some ideas.

1. The temperature of the water.

2. The amount of the solute. E.g. How much salt or sugar.

3. Stirring and how much stirring.

4. The volume of water used. This will affect the final concentration of

the soup and so the flavour of the soup.

5. The particle size.

For You To Think About:

When we investigate these factors we will have

to devise a fair test. What do we mean by this?

We will only change one variable at a time. How will we record our results?

MAKING CLEAR SOUP




Background information for group work on rate

of dissolving

An examination of the various factors that

affect the rate of dissolving.

You will work in groups to investigate the

various factors you have identified. Choose

one of the workcards. More than one group

could work on the same variable. If you want to

use each others results it will be critical that you

carry out the same investigation procedures. This will allow you to fairly

average the combined results. This is called standardising the technique. It

is also useful if there is an error in, e.g. measuring the masses of salt or the

volume of water to be used.

Why do the soup manufactures have to do this?

If your group has chosen to investigate particle size, how will you determine the sizes of the particles? A seive might have to be used here.

You should look at the instructions on the various packets of soup.

Do they all follow the same method? If not, can you suggest why not? Why is the heat reduced after adding the dried soup mix to the boiling water and stirring it?

When you have finished your investigation into your

chosen factor, a spokesperson from your group will

present the groups results to the class or you will

complete a lab write up of your work or you may

present a powerpoint presentation of your findings.

MAKING CLEAR SOUP




Workcard 1:

The Temperature of the Water.

Some of the instructions on the soup packets say to boil water before adding the dried

contents. You will investigate the rate of dissolving of salt in water of different

temperatures.

Materials:

4 100 ml

beakers

measuring cylinder

thermometer

hot plate/ kettle

sodium chloride

spatula

stirring rod

labels/waterproof pen

stopwatch

Method:

Label the four beakers 1,2,3, and 4. Add equal volumes of water at these temperatures. 10 oC, 20 oC, 40oC, 60oC. Add equal masses of sodium chloride to each of the four beakers. If

you decide to stir, all beakers must be stirred the same way.

Results:

Record you results in a table:

Beaker Temperature oC

At start At end Time (secs) to dissolve

1

2

3

4

Evaluation of Results:

How do you know the temperature was measured correctly?

What would be the advantage of repeating your investigation and taking an average of your

results?

Why measure the temperature at the start and at the end of the investigation?

Conclusion:

What does your investigation tell you about the effect of the temperature of the water on

the rate of dissolving? What advice would you suggest when heating water for dissolving

dried soup mix?

MAKING CLEAR SOUP




Workcard 2

The amount of the solute. E.g. How much salt or sugar will dissolve in a given amount

of water?.

Look at the soup packets. How much do they contain? You could work out how much sugar

there is in your packet of soup by examining the nutritional data. The data will be given for

100g. Your packet may contain less than this. You will investigate how much salt or sugar

will dissolve in a given amount of water.

Materials:

4 100 ml beakers

thermometer

measuring cylinder

hot plate/ kettle,

(optional)

sugar/salt

spatula/balance

stirring rod


stopwatch

Method:

Label the four beakers 1,2,3, and 4. Add equal volumes of water, all at the same

temperature. Add your selected numbers of spatulas of salt or sugar to each of the four

beakers. If you use a balance to weigh different masses of solute record that in the table

below. If you decide to stir, all beakers must be stirred the same way. Time how long they

take to dissolve.

Results:

Record your results in a table:

Beaker Numbers of spatulas of

salt/sugar or masses of solute Time (secs) to dissolve

1

2

3

4


How do you know the spatulas were all the same measurement?

What would be the advantage of repeating your investigation and taking an average of your

results? Do you think there will be a difference between salt or sugar?

Conclusion:

What does your investigation tell you about the effect of changing the masses of solute on

the time taken to dissolve? What restrictions do you think the soup manufacturers have as

to the mass of dried soup mix that can go in a packet?

MAKING CLEAR SOUP




Workcard 3

Stirring and How Much Stirring?

What will you stir with? What is suggested on the packet? How will you standardize your

stirring technique? A magnetic stirrer may be of use to you here.

Materials:

4 100 ml beakers

measuring cylinder

thermometer

hot plate/ kettle,

(optional)

sugar/salt

spatula/balance

stirring rod


stopwatch

Method:

Label the four beakers 1,2,3, and 4. Add equal volumes of water, all at the same

temperature. Add the same mass of salt or sugar to each of the four beakers. Decide what

you will use to stir your solution with. This could be a stirring rod, a spoon, a spatula, a fork

or a magnetic stirrer. All beakers must be stirred the same way but for different lengths

of time or at different rates. Time how long they take to dissolve.

Results:

Record your results in a table:

Beaker Stirring times or rates Time (secs) to dissolve

1

2

3

4


How could you ensure that the stirring rates were all changed in one aspect only? What

would be the benefits of a magnetic stirrer?

Conclusion:

What advice would you now give on the soup packet for stirring utensil? Do you think it

would be important as to when the soup was stirred? Are there any differences on this in

the instructions on your soup packets?

MAKING CLEAR SOUP




Workcard 4

The Volume of Water Used.

Why will it be important to use water at the same temperature? Is there a minimum volume

of water that could be used? How could this be determined?

Materials:

4 100 ml beakers

measuring cylinder

thermometer

hot plate/ kettle,

(optional)

sugar/salt

spatula/balance

stirring rod


stopwatch

Method:

Label the four beakers 1,2,3, and 4. Add your selected volumes of water,

all at the same temperature. Add the same mass of salt or sugar to each

of the four beakers. All beakers must be stirred the same way, at the

same rate.Time how long they take to dissolve.

Results:


Beaker Volume of water (ml) Time (secs) to dissolve

1

2

3

4


Did you choose an even range of volumes of water? Why might this be of importance?

Conclusion:

How much water do soup manufacturers allow for dissolving their soup mix? What factors

do you think they have had to consider? How many people are the packets, on average,

supposed to feed?

MAKING CLEAR SOUP




Workcard 5

The Particle Size. It would be possible to look at granulated, castor and icing sugar here.

You will have more particle size choices if you choose brown sugar.

Materials:

4 100 ml beakers

measuring cylinder

thermometer

hot plate/ kettle, (optional)

sugar ( granulated, castor, icing) /salt

(sea salt, powdered salt) You need four

choices here.

spatula/balance

stirring rod


stopwatch

Method:

Label the four beakers 1,2,3, and 4. Add the same volumes of water, all at the same

temperature. Add the same mass of salt or sugar ,of the chosen particle size, to each of

the four beakers. All beakers must be stirred the same way, at the same rate.Time how long

they take to dissolve.

Results:


Beaker Particle size Time (secs) to dissolve

1

2

3

4

Evaluation of Results: How did you decide the range of particle sizes? Why might this be

of importance? How could you measure particle size more scientifically? Your work on soil

particle size might help you here. What units can be used for particle size?

Conclusion: Do any soup manufacturers use brown sugar in their ingredients? Why might

they use brown instead of white sugar? What other factors about particle size do you think

they have had to consider? Might there be any disadvantages to using icing sugar?

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Workcard 6

Can you think of another factor the soup manufacturers might have to consider? How could

you investigate this? Make up your own work card, using the methods used before, to

investigate your chosen variable.

Variable:

Materials:

Method:

Results:

Evaluation of results:

Conclusion:

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Teacher Supplementary Notes

Teacher Demonstration

You have got two beakers of water, one has salt and the other

does not. You heat them both for the same length of time.

Do they both end up at the same temperature?

Make a prediction about your experiment.

Teacher Discussion of the hypothesis that:

The time required to cause a change in

temperature increases as the amount of material

dissolved in the water increases. The more

dissolved substance the less the rise in

temperature.

Investigation of the hypothesis

Your first experiment will look at collecting data to test this hypothesis/

prediction. The equipment list and directions you need are given below:

4 100 ml pyrex beakers

1 graduated measuring cylinder

1 spatula

1 hot plate/ bunsen burner + tripod

+ heat mat

1 thermometer

1 stopwatch

sugar or salt

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Method:

Label the beakers 0,1,2 and 3.

Measure 50 ml of water into each.

Dissolve one spatula of salt or sugar in beaker 1 and 2 spatulas in

beaker 2; and 3 in beaker 3.

Do not put any sugar or salt in beaker 0.

Heat each beaker for three minutes.

Record the change in temperature in the table below.

Amount of sugar or salt

(spatulas)

0 1 2 3

Temperature change

( oC)

Why did you use beaker 0?

What do your results show?

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Examining the concept of controls in experiments.

To know that the sugar or salt is causing the change, you

need to know what happens when no sugar or salt is used.

The beaker with no sugar or salt is a standard of

comparison to which all the other beakers can be

compared. Most experiments include a standard of

comparison, called a control or control group.

In some experiments, such as this one, the control is called the no

treatment control. In other experiments all groups receive a treatment

(some amount of the manipulated variable).

The experimenter must then select one of the levels of the manipulated

variable to serve as the control group. The

level selected is usually the normal or typical

case.

For example, in an experiment on the effect of

depth of seed on seed germination, the control

might be the recommended or normal planting

depth; other planting depths might be deeper

or shallower than the control. This kind of control is called an

experimenter-selected control.

Using the data collected from your experiment, construct

a graph and a statement about the relationship between

the amount of dissolved sugar or salt and the rate of

temperature change. Be sure to give the graph a title.

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Statement of Relationship

The temperature change decreases, as the amount of

dissolved sugar or salt increases. The addition of e.g.

more than two spatulas of sugar or salt results in no

increase in temperature change. The more dissolved

substance, the more heat required to get to a given

temperature. Your statement may be different depending on your

experimental results.

Questions:

1. What does this tell a soup manufacturer?

2. What advice could you now give to the soup manufacturer?

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Further related investigations and identifying variables.

Now we are going to use these findings and investigate soup solubility

further.

1. What is the effect of temperature on the time a stock cube takes to dissolve?

2. Does the mass of the stock cube have an effect on

the temperature change of the water? 3. Does the temperature of the water effect the change in temperature

when adding the stock cube?

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Investigation:

Examine the question in more detail.

What are some of the variables that could affect the dissolving time of the stock cube?

1. Amount of water

2. Mass of stock cube

3. Type of stock cube

4. Shape of container

5. Temperature of the water

6. Length of stirring time

If the variable, temperature of the water, was selected for your

investigation, you could make this prediction: The time required to totally

dissolve a given mass of stock cube decreases with an increase in the

temperature of the water acting as the solvent. You will now gather data to

test your hypothesis. The equipment list and directions on what to do are

given below.

Method



1 graduated measuring cylinder

1 knife

1 balance

1 hot plate

1 thermometer/ 4 stick-on

thermometers

stock cubes

stop watch

waterbaths at 10oC, 20oC, 40oC,

and 60oC

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Method (continued):

Label your 100 ml beakers 1,2,3, and 4.

Measure 50 ml of water into each as follows;

Beaker 1 2 3 4

Temperature of

water oC 10 20 40 60

Place the 100 ml beaker into a 500 ml beaker of water at the required

temperature. This will help to maintain the correct temperature.

Using your knife and the balance, measure four equal pieces of stock

cube.

Note the temperature of each beaker and add the pieces of stock

cube simultaneously to each.

Time how long it takes for the stock cube to dissolve. Once the

experiment is finished note the temperature in all beakers.

Beaker Temperature

oC

Time

(min) Observations on stock cube

1

2

3

4

Draw a pie chart to show the differences in each stock cube, using

different colours for each temperature.

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Skills needed when identifying variables

After completing this assignment you should be able to:

1. Identify the variables in a written statement or

description of an investigation.

2. Classify the variables as independent or dependent.

You will have to make several measurements in the following activities. This

will help you to identify the different variables involved.

Investigation

To identify different variables involved in the solubility of calcium chloride.

Method:

Safety goggles

4 small identical beakers

thermometer

spatula

stirring rod

1 litre beaker

calcium chloride ( this is a

chemical used to control ice

on roads)

graduated cylinder

labels/pen

Fill the litre beaker with tap water at room temperature.

Use the graduated cylinder to fill each small beaker with

75 ml of water.

Measure the temperature of the water in one of the

beakers.

Label it container A.

Add one spatula of calcium chloride and using a stirring rod,

stir until it dissolves.

Measure the temperature of the water as soon as the calcium chloride

has dissolved.

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Answer the following questions:

1. What was the initial temperature of the water before

adding the calcium chloride?

2. What was the temperature after adding the calcium chloride?

3. What happened to the temperature of the water in the beaker?

4. How many degrees did the temperature change when you added one

spatula of calcium chloride?

You may have found that the temperature increased about 3 to 6 degrees

Celcius. The temperature could be more or less than this depending on the

amount of water you used and the amount of calcium chloride.

You will now record your measurements in the table below.

You should record both the number of spatulas of calcium chloride

added and the change in temperature for each small beaker.

Beaker Number of spatulas of

calcium chloride

Temperature change

(oC)

A

B

C

D

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Repeat the procedure described for beaker A with beaker B. This

time add two spatulas of calcium chloride.

Again, determine how much the temperature changes from the initial

temperature of the water.

Record your data in the table.

Repeat the procedure for beakers C and D, using three and four

spatulas of calcium chloride respectively.

Answer the following questions:

1. Did you use the same amount of water in each beaker?

2. Did you use the same amount of calcium chloride in each beaker?

3. Did the temperature change the same amount for each beaker?

4. What prediction would you make if you added five spatulas of calcium

chloride to the same amount of water?

If you followed the directions carefully, you should have used the same

amount of water in all four beakers. You should have added different

amounts of calcium chloride to each beaker ( one spatula to beaker A, two to

beaker B, three to beaker C and four to beaker D,) The temperature should

have increased by different amounts in the beakers.

The increase was greater for those beakers in which

more calcium chloride was dissolved. Finally, you

probably predicted that the temperature change would

be even greater if five spatulas of calcium chloride were

added.

MAKING CLEAR SOUP




Technical Guide:

Graduated cylinders

Beakers

Water

Salt (25g on a piece of paper)

Stirring rods

Spatulas

Balances

Selection of packet soups to

compile list of ingredients

Graph paper

Thermometers

Graduated cylinders

Salt

Stirring rods

Spatulas

Cornflour

Test tubes

Test tube racks

Stock cubes

Measuring cylinder

Knife

Balance

Hot plate

Thermometer

Stopwatch

Torch/light source to show colloids

Gelatine

Beakers

Sodium chloride (salt)

Materials for Workcards 1-5

100 ml beakers ( need four per

group)

measuring cylinders

thermometers

hot plate/kettle

sodium chloride ( table salt, sea

salt, powdered salt) or sugar ( icing

sugar, caster sugar, granulated

sugar)

spatulas

stirring rods / magnetic stirrers

labels/ waterproof pens

stopwatches

balances

spoons, forks, knives

MAKING CLEAR SOUP




Materials needed to do workcards 1 – 5

100 ml beakers ( need four per group)

measuring cylinders

thermometers

hot plate/kettle

sodium chloride ( table salt, sea salt, powdered salt)

or sugar ( icing sugar, caster sugar, granulated

sugar)

spatulas

stirring rods / magnetic stirrers

labels/ waterproof pens

stopwatches

balances

spoons, forks, knives

MAKING CLEAR SOUP




Glossary

o Colloidal dispersion: a dispersion where the dispersed particles are

larger than molecules but smaller than the particles in true suspension

o Concentration: strength of a solution

o Diffusion: movement of molecules from an area of high concentration

to an area of low concentration

o Dissolve: to mix completely a solute with a solvent to form a solution

o Emulsion: a mixture in which one liquid is dispersed in another, such as

oil in water

o Heterogeneous: not of uniform composition

o Homogenous mixture:of uniform composition throughout

o Insoluble: unable to be dissolved

o Mechanical mixture: a mixture made up of two or more easily

identifiable parts

o Molecular: composed of molecules

o Molecules: the smallest part of a pure substance which retains the

properties of that substance. It may consist of one or more atoms.

o Phase: a uniform part of a mixture

o Saturated: not able to dissolve any more solute

o Solubility: the property of being able to dissolve. More specifically, it

refers to the mass of a solute that can dissolve in a given amount of

solvent to form a saturated solution at a particular temperature

o Soluble: able to be dissolved

o Solute: the substance that dissolves in a solvent to form a solution

o Solution: the product formed when a solute dissolves in a solvent

o Solvent: the substance that dissolves a substance to form a solution

o Supersaturated: a solution that contains more dissolved solute than

can normally be dissolved in a given mass of solvent at a particular

temperature

o Suspension: a mixture containing floating particles that will settle

after sometime

o Tyndall effect: the scattering of a beam of light by reflection from

tiny suspended particles

o Unsaturated: able to dissolve more solute

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