Experiment
Lehrerheft description/Manual
zur Experimentierbox
Heat
With
worksheet
Heat
2
Heat
Science kit
Heat
Order no. 31799
This Science kit is recommended for students at the age of 7 – 10.
Contents
List of components............................................................................................... 4
Storage plan.......................................................................................................... 5
1Experiments................................................................................................ 6
1.2
Experiment 1: Heating and cooling water.................................................... 6
1.3
Experiment 2: Heating and cooling methylated spirits.................................. 6
1.3
Experiment 3: How does a thermometer function?....................................... 7
1.4
Experiment 4: What is a thermometer for?................................................... 7
1.5
Experiment 5: The Celsius scale.................................................................... 7
1.6
Experiment 6: Taking temperature measurements and reading exercises...... 8
1.7
Experiment 7: Converting a liquid into a gas................................................ 8
1.8
Experiment 8: Water evaporates, vaporizes too............................................ 9
1.9
Experiment 9: Vaporizing liquids are cooling................................................ 9
1.10 Experiment 10:Can a gas be re-converted into a liquid?............................... 9
1.11 Experiment 11:What happens when steam cools down?............................ 10
1.12 Experiment 12:The water cycle.................................................................. 10
1.13 Experiment 13:How water particles unite................................................... 11
2
Underlying principles............................................................................... 11
Worksheet........................................................................................................... 13
© 2008 Cornelsen Experimenta, Berlin
All rights reserved.
The work and parts of it are protected by copyright.
Every use for other than the legal cases requires the previous written agreement by Cornelsen Experimenta.
Hint to §§ 46, 52a UrhG: Neither the work or parts of it are allowed to be scanned, put into a network or
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This includes intranets of schools or other educational institutions.
Cornelsen Experimenta products are designed for educational use only and are not intended for use in
industrial, medical or commercial applications.
We assume no liability for damages which are caused by inappropriate usage of the equipment.
3
Heat
List of components
Illustr. no. Qty. Description
1
2
3
4
5
6
7
7
7
8
9
10
11
12
12
12
13
14
15
16
17
18
19
–
Order no.
16 Glass tubes, 220 x 6 mm Ø............................................................ 12859
15 Droppers, plastic............................................................................ 12875
20 Candles in metal holders................................................................ 12816
15 Thermometers, without graduation................................................ 12743
15 Thermometers, -3 °C to +103 °C.................................................... 12735
1Atomizer........................................................................................ 12999
1 Food colouring, blue...................................................................... 12913
1 Food colouring, red....................................................................... 12921
1 Food colouring, yellow................................................................... 12930
15 Insulating cases for beaker.............................................................. 12808
15 Beakers, 100 ml, plastic, with graduation....................................... 12794
15 Erlenmeyer flasks, glass, heat resistant, 25 ml................................. 12832
15 Safety pins, 40 mm........................................................................ 12867
15 Red pegs........................................................................................ 12751
15 Yellow pegs.................................................................................... 12760
15 Blue pegs....................................................................................... 12778
1 Immersion heater, 300 W/230 V.................................................... 12891
1 Funnel, plastic, 70 mm Ø............................................................... 12956
1 Tube brush..................................................................................... 12964
1 Beaker, glass, 250 ml, heat-resistant, with graduation.................... 12905
15 Plastic containers for activities........................................................ 12883
15 Rubber stoppers with bore............................................................. 12840
15 Bridge-shaped stands..................................................................... 12824
1 Thermometer model for demonstration......................................... 12948
Enclosed printed material
–
1
Experiment description/Manual ‘Heat’......................................... 317996
–
1
Storage plan ‘Heat’.................................................................... 3179936
Additional set ‘Heat 2’
–
3
Thermos flasks (For the transportation of hot water and ice cubes
into the classroom.)....................................................................... 36680
Please note:Some experiments of the Science Kit “Heat” use an unshielded flame or
an immersion heater as heating source. Therefore all experiments have
to be accomplished with a maximum of accuracy and cautiousness to
prevent accidents like burns or scalds.
4
Heated elements must cool down before being restored in the kit.
Heat
Storage plan
5
Heat
1Experiments
1.2 Experiment 1
Heating and cooling water
Fill the Erlenmeyer flask to the brim with (coloured) water. The rubber stopper is then inserted in the flask. The glass tube is inserted in the hole in the
stopper, which causes the water to rise in the glass tube. The level of the
liquid in the tube is marked using the blue plastic peg.
Now place the flask, filled with water, on the bridge-shaped stand and heat
it using a candle in a metal holder. As it is heated the level of the water in the
tube rises, because its volume is increasing. The new water level is marked
with a red peg.
To cool the flask, place it in the plastic beaker, which should be filled with
cold water, and possibly ice cubes as well.
Materials: 1 glass tube (1)
1 candle in metal holder (3)
1 food colouring (7)
1 plastic beaker (9)
1 Erlenmeyer flask (10)
1 peg, red (12)
1 peg, blue (12)
1 rubber stopper (18)
1 bridge-shaped stand (19)
Additionally: 1 thermos flask containing cold water or ice cubes
1.3 Experiment 2
Heating and cooling methylated spirits (inflammable!!)
The Erlenmeyer flask is filled to the brim with coloured methylated spirits.
Then the rubber stopper is inserted in the flask. The glass tube is inserted
in the stopper.
Because methylated spirits is inflammable for heating the spirits we do not
use any candles. Instead a beaker filled with hot water is placed in the
insulating case.
Then the Erlenmeyer flask with rubber stopper and glass tube is placed in the
plastic beaker. As it expands the methylated spirits rises up the glass tube.
When it cools the level falls again. When heated, methylated spirits expands
more than water.
Materials: 1 glass tube (1)
1 food colouring (7)
1 insulating case (8)
1 plastic beaker (9)
1 Erlenmeyer flask (10)
1 rubber stopper (18)
Additionally: 1 thermos flask containing hot water (70 °C), 1 thermos flask
containing cold water or ice cubes, methylated spirits
6
Heat
1.3 Experiment 3
How does a thermometer function?
The thermometer without graduation is alternately dipped into the beakers
containing water at different temperatures.
The thermometer functions in the same way as the equipment set up in
experiments 1 and 2: when it is heated the alcohol in the thermometer
expands, and it contracts as it cools.
Materials: 1 thermometer without graduation (4)
2 plastic beakers (9)
Additionally: 1 thermos flask containing hot water, 1 thermos flask containing ice cold water
1.4 Experiment 4
What is a thermometer for?
Fill the beakers with water at varying temperatures: approx. 55 °C, 25 °C
and ice cold. Test the temperature by placing your hand in it.
Water at 25 °C feels cold if your hand has previously been held in hot water.
However, if you first place your hand in cold water and then in water at
25 °C, the water feels warm.
If a thermometer is used to measure the temperature it will always indicate
the same temperature in the lukewarm water, regardless of whether it has
been held in hot or cold water beforehand. Therefore, thermometers have
to be used for exact temperature measurements.
Materials: 1 thermometer, –3 °C to +103 °C (5)
3 insulating cases for beaker (8)
3 plastic beakers (9)
Additionally: 1 thermos flask containing hot water, 1 thermos flask containing ice cold water, tap water
1.5 Experiment 5
The Celsius scale
The Celsius scale is defined between two specific temperatures, the melting
point of ice (0 °C) and the boiling point of water (100 °C).
On a thermometer without graduation these two temperature points can
be determined as follows: The teacher fills a large heat-resistant beaker with
water. An immersion heater is used to bring the water to boil. (Never use
the heater without any water!)
Each group places the thermometer without graduation into the boiling
water and waits until the liquid in the thermometer stops rising. This point
is to be marked with a red peg.
Then the pupils fill the plastic beaker with water and ice cubes. They place
the thermometer in the water and wait until the liquid in it stops moving.
This point is to be marked with a blue peg.
7
Heat
Compare with the thermometer with Celsius scale, which shows 100 equal
divisions between the marked two points (0 °C to 100 °C).
Materials: 1 thermometer without graduation (4)
1 thermometer -3 °C to 103 °C (5)
1 plastic beaker (9)
1 red peg (12)
1 blue peg (12)
1 immersion heater (13)
1 beaker, heat-resistant (16)
Additionally: 1 thermos flask containing hot water, 1 thermos flask containing ice cold water
1.6 Experiment 6
Taking temperature measurements and reading exercises
The thermometer can be used to measure different temperatures e.g. classroom temperature, temperature of cold and warm water, hot tea, temperature of bulb after light has been switched on for a few minutes etc.
For reading exercises and entries the worksheet at the end of this manual
should be photocopied.
Material: 1 thermometer, -3 °C to +103 °C (5)
1.7 Experiment 7
Converting a liquid into a gas
Close the Erlenmeyer flask with the rubber stopper, invert it and place on the
stand. Place a drop of Eau-de-Cologne or methylated spirits on the middle
of the base of the flask using a dropper.
The drop becomes smaller and smaller until it is no longer visible. The liquid
has vaporized/evaporated. It has turned into a gas.
A gas consists of tiny particles, invisible to the naked eye. However, it is sometimes possible to smell these particles even when the liquid has evaporated
completely, e.g. in the case of Eau-de-Cologne or methylated spirits.
Materials: 1 dropper (2)
1 Erlenmeyer flask (10)
1 rubber stopper (18)
1 bridge-shaped stand (19)
Additionally: Eau-de-Cologne or methylated spirits
8
Heat
1.8 Experiment 8
Water evaporates, vaporizes too
The Erlenmeyer flask is set up as in experiment 7 but now a drop of water
is placed on its base.
In this case too, the drop of water evaporates after a while even though this
happens slower than it did in experiment 7. (Different liquids evaporate
at different speeds.)
Examples of water vaporization/evaporation in every-day life:
•Wet laundry dries
•Rainwater on car windows
(the drops gradually become smaller and smaller until the window is
completely dry)
•Water in an aquarium evaporates
(water must be added from time to time)
Materials: 1 dropper (2)
1 Erlenmeyer flask (10)
1 rubber stopper (18)
1 bridge-shaped stand (19)
Additionally: some water
1.9 Experiment 9
Vaporizing liquids are cooling
With a thermometer you determine the room temperature and the temperature of methylated spirits (inflammable!) filled in a plastic beaker.
As the thermometer is pulled out of the liquid the temperature shown by
the thermometer is decreasing. (Due to the evaporating methylated spirits
on the thermometer.)
This cooling effect can also be felt by wetting a finger with methylated
spirits.
Materials: 1 thermometer, -3 °C to +103 °C (5)
1 plastic beaker (9)
Additionally: methylated spirits
1.10 Experiment 10
Can a gas be re-converted into a liquid?
Add some hot water (at least 70 °C) to the Erlenmeyer flask. Close the flask
with a rubber stopper.
The glass fogs up. The water particles which have evaporated deposit on
the glass. A gas has been converted into a liquid.
Materials: 1 Erlenmeyer flask (10)
1 rubber stopper (18)
Additionally: 1 thermos flask or glass with very hot water
9
Heat
1.11 Experiment 11 (Demonstration)
What happens when steam cools down?
Fill a heat-resistant beaker with water and bring the water to the boilingpoint with an immersion heater. Now hold the plastic container filled with
ice cubes over the steam.
The water boils. Numerous particles escape from the water, some of which
rise as gas bubbles (steam).
The steam becomes mist (clouds) in the cooler air as the particles become
more densely packed.
Drops form on the cool base of the container. They condense.
Materials: 1 immersion heater (13)
1 heat-resistant beaker (16)
1 plastic container (17)
Additionally: 1 thermos flask with ice cubes
1.12 Experiment 12
The water cycle
Water evaporates everywhere: Invisible water particles rise from the sea, from
fields and forests. These evaporated water particles condense where the air
is colder and form (mist) clouds.
When the air becomes even colder or the wind moves these clouds to cooler
regions, the mist particles unite to form larger drops which, because of their
weight, fall downwards: It rains.
The water cycle is complete. The rain evaporates, the invisible particles
rise etc.
10
Heat
1.13 Experiment 13
How water particles unite
Fill the atomizer with water. Spray the water onto a window or blackboard
from a distance of approximately 30 cm. The tiny particles from the atomizer form a barely visible water cloud, but on the sprayed surface they unite
after a while and form drops of increasing size.
Materials: 1 atomizer (6)
Additionally: some water
2 Underlying principles
Heat and thermometer
When solid bodies, liquids or gases are heated their volume (the amount
of space that they occupy) generally increases. For example, when warmed
by 1 degree Celsius (= 1 Kelvin), 1 litre of water and 1 litre of mercury both
expand by 0,2 millilitre (= 0.2 cubic centimetre), alcohol by 1.1 millilitre
(= 1.1 cubic centimetre).
When cooled, the volume decreases again. However, if water (under normal pressure) is cooled, its volume only decreases until it reaches 4 °C (Celsius). If the water is cooled further to 0 °C its volume increases again. When
water at 0 °C changes to ice at 0 °C there is a sudden increase in volume.
This they cool and solidify.
Temperatures are measured using thermometers. Liquid thermometers
consist of a liquid-filled container (the bulb) connected to a very narrow
tube. If the temperature rises, the liquid will expand. The level of the liquid
in the tube at any given time can be read from a scale. Thermometers are
usually filled with alcohol or mercury.
On the Celsius thermometer scale the freezing point of water is marked at
zero degrees Celsius (0 °C), and the boiling point of water at 100 degrees
Celsius (100 °C). On the Fahrenheit thermometer scale the freezing point
of water is shown as +32 °F and the boiling point of water as +212 °F. Readings in degrees Fahrenheit are still used in Britain and North America.
The clinical thermometer
Whereas outdoor, room and bath thermometers always show the temperature to which they are being exposed, the clinical thermometer is a so-called
maximum thermometer. In other words, once the reading has reached its
highest level, it remains there.
This is achieved by means of a constriction between the bulb and the tube.
As the mercury expands it is able to pass through this constriction, but as it
cools it retracts, causing a break in the thread of mercury at this point. This
enables a permanent reading.
Only by shaking the clinical thermometer the liquid is forced back
­through the contriction into the bulb.
11
Heat
Some selected temperatures in degrees Celsius (°C)
6000
surface of the sun
2500
filaments in a lamp
1535
iron melts
1063
gold melts
950 to 1200
flame of gas burner
800
match flame
357
mercury boils
327
lead melts
270
electrical soldering iron
220
smoothing iron (linen setting)
100
water boils
78
57,8
36 to 37
0
-39
-89,2
lowest air temperature ever measured on Earth
-180
air liquefies
-273
lowest possible temperature (absolute zero)
alcohol boils
highest air temperature ever measured on Earth
body temperature of healthy human being
water freezes
mercury solidifies
Evaporation
The conversion of a substance from the liquid state into the gaseous state
is referred to as evaporation.
There are two methods of evaporation: boiling and vaporization.
If water is heated to 100 °C, bubbles rise to the surface because the water
particles start moving rigorously as a result of the heat supply. The water
“boils”. The rising bubbles contain an invisible gas: water vapour.
Vaporization is the name given to the process when a liquid evaporates
at a temperature below its boiling point. In this case, only particles on the
liquid surface enter the gaseous state.
Condensation
The reverse process to evaporation, i.e. the conversion of a substance from
the gaseous state into the liquid state, is known as condensation.
Small droplets of liquid form from the invisible gas over the boiling water
upon cooling and can be observed as a cloud or mist.
12
1 Reading exercises
Heat
Write down the temperatures shown by the thermometers.
Worksheet © Cornelsen Experimenta
13
Heat
Additional set ‘Heat 2‘
Insulated wide neck vessels, 3 pcs.
For the appropriation of warm and cold water as well as
ice cubes for thermometer- and temperature-compound
experiments.
In a storage tray with lid.
Content of each vessel: 1 liter
Order no. 36680
14
Experiment description/Manual ‘Heat‘
Order no. 31799 6
Holzhauser Straße 76
D-13509 Berlin/Germany
© 2008 Cornelsen Experimenta, Berlin Tel.: +49 30 435 902-0
Fax: +49 30 435 902-22
eMail: [email protected]
Internet: www.corex.de
03.00