Heating and cooling curves - · PDF file• Investigate and record a cooling curve. •...

Heating and cooling curves

17/05/2016 Cooling off

©cgrahamphysics.com 2016

Where is the best place to cool off? Antarctica

Yakutsk, Russia

North Ice, Greenland

Yukon, Canada 17/05/2016 ©cgrahamphysics.com 2016

Where is the best place to warm up?

Death Valley, California

TIRAT ZVI, ISRAEL

DEHLORAN, IRAN

OODNADATTA, AUSTRALIA

17/05/2016 ©cgrahamphysics.com 2016

Starter

• State what is meant by heat.

• State what is meant by temperature

• Does heating always result in a rise in temperature? If not, why not?


Aim • Describe the difference between heat and temperature.

• Know what energy changes are taking place during changes of state.

• Investigate and record a cooling curve.

• Describe and understand heating and cooling curves.

Key words

• Heat 열

• Temperature 온도

• Energy 에너지,

• State change 상태 변화


The bigger picture Have you ever wondered

Which has more heat?

450𝐶

Which has more temperature?


Definition

• Heat is the transfer of energy from one object to another. It is the total energy the particles in a substance have

• Temperature is a measure of how much heat energy something has. It is the average kinetic energy of the particles in the substance.


What happens to the particles?

• Melting

• Freezing

• Boiling

• Condensing

• A) what state is it occurring? (i.e. solid to gas)

• B) what happens to the amount of energy the particles have? Increasing, decreasing

• C) What is happening to the attractive forces pulling the particles together? Getting stronger, getting weaker


Changing state • Take the temperature of ice melting until water

starts boiling every 30 second.

• Watch the temperature carefully.


Reading No. Temperature / C 1 20 2 21 3 22 4 23 5 25 6 25 7 25 8 25 9 25

10 25 11 28 12 31 13 34 14 37 15 41 16 45 17 49 18 53 19 57 20 61

Reading No. Temperature / C 21 65 22 69 23 73 24 77 25 81 26 85 27 89 28 89 29 89 30 89 31 89 32 93 33 98 34 103 35 108 36 113 37 118 38 123 39 128


5 10 15 20 25 30 35 40

140

130

120

110

100

90

80

70

60

50

40

30

20

10

0

Tem

pera

ture

/ °

C

Heating a Solid

Reading

Number


5 10 15 20 25 30 35 40

140

130

120

110

100

90

80

70

60

50

40

30

20

10

0

Tem

pera

ture

/ °

C

Heating a Solid

Reading

Number

0

20

40

60

80

100

120

140

0 10 20 30 40 50 60 70

Tem

pera

ture

/ C

Reading Number

Heating a Solid


Results

a) Where on your graph does temperature increase

smoothly each minute? (3 places)

b) What is the substance doing when there is no

change in temperature?

c) Where does the inputted heat energy go when the

temperature doesn’t increase?


1.To get a material to change state requires heat

energy.

2.When we heat ice, the temperature of the ice doesn’t

change while its melting, even though we’re still

supplying heat.

3.The energy goes to breaking bonds between atoms,

allowing them the move with more freedom!

Time

4.This can be seen in a

graph when we heat

a material and record

its temperature:

Heating and State Changes


Plenary: Fill in the blanks • When a heated solid turns into a _____the bonds of the

solid are been______. This requires _____and as such is keeping the temperature _____than you would expect.

• eg. Flat line despite continuous heating. Similarly...

• When a liquid goes to a _____the bonds of the solid are been_____. This ______energy and as such is keeping the substance temperature ______than you would expect.

• eg. Flat line despite continuous cooling.

LIQUID

BROKEN ENERGY

LOWER

SOLID

MADE RELEASES

HIGHER


Plenary: MWB • Using simple particles drawings:

• Draw the structure of a piece of ice in a beaker.

• Draw the structure of water in the beaker.

• Have the water molecules gained or lost energy as the ice melted?

• Draw a simple heating curve showing temperature against time over the period that some ice is being melted and then boiled. Label the melting and boiling points.


Key words

• Heat - the transfer of energy from one object to another. It is the total energy the particles in a substance have

• Temperature - a measure of how much heat energy something has. It is the average kinetic energy of the particles in the substance

• Energy - given to a substance in form of thermal energy or power over time

• State change - a substance changes between the three states of matter, solid, liquid and gas


Heating and cooling curves - · PDF file• Investigate and record a cooling curve. •...

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