1. Use the specific heat capacity formula to answer the following:
1) How much heat is required to raise the temperature of 2kg of lead by 30°C if the specific heat capacity of lead is 130 J/kg°C?
2) What is the specific heat capacity of paraffin if 2200J raises the temperature of 0.1kg from 10°C to 20°C?

2. Learning Objectives
By the end of this lesson you should…
Be able to describe the change in temperature of a substance as heat energy is supplied or removed
Understand qualitatively and quantitatively the concept of the specific latent heat of a material.
Be able to explain the variation in temperature in terms of intermolecular forces

3. EXTENSION – include temperature values on your axis
Learning Objectives
By the end of this lesson you should…
Be able to describe the change in temperature of a substance as heat energy is supplied or removed
Understand qualitatively and quantitatively the concept of the specific latent heat of a material.
Be able to explain the variation in temperature in terms of intermolecular forces
YOUR TASK:
On a post-it-note sketch a graph of temperature against time for ice (-50°C) being turned into steam (150°C)
EXTENSION – include temperature values on your axis

4. Now complete the experiment following the method provided
Learning Objectives
By the end of this lesson you should…
Be able to describe the change in temperature of a substance as heat energy is supplied or removed
Understand qualitatively and quantitatively the concept of the specific latent heat of a material.
Be able to explain the variation in temperature in terms of intermolecular forces
Now complete the experiment following the method provided
The plot of your results will provide you with a section of your sketch graph.
When you are finished compare the results – does the pattern match? If not, why not? If so then how did you know?

5. This flat line shows where energy is being used to push the particles further apart and break the final intermolecular bonds
Temp/OC
This slope shows how energy is being used make molecules vibrate more and move faster so further increasing the KE of molecules
150
100 50
-50
This slope show how energy is being used make molecules move faster – NO intermolecular bonds left
Is this a heating curve for ice?
Write a description of what is happening at each stage of this heating curve.
You also need to estimate /calculate energy input needed at each stage on graph
This slope shows how energy is being used make molecules vibrate more and so increase KE of molecules
Time/s
This flat line shows where energy is being used to break intermolecular bonds – this has to be done during melting

6. Condensing water 150 Temp/OC 100 50 Time/s -50
-50
As the question what happens to latent heat when steam condenses all freezes?
Heat energy is given out.
Time/s

7. LATENT HEAT Energy needed to break bonds and melt or boil
Learning Objectives
By the end of this lesson you should…
Be able to describe the change in temperature of a substance as heat energy is supplied or removed
Understand qualitatively and quantitatively the concept of the specific latent heat of a material.
Be able to explain the variation in temperature in terms of intermolecular forces
Energy needed to break bonds and melt or boil
a material is known as
LATENT HEAT
Hidden:
Additional heat energy doesn’t show
as temperature change

8. The energy required to change the state of 1kg of a substance
Learning Objectives
By the end of this lesson you should…
Be able to describe the change in temperature of a substance as heat energy is supplied or removed
Understand qualitatively and quantitatively the concept of the specific latent heat of a material.
Be able to explain the variation in temperature in terms of intermolecular forces
Specific Latent Heat
The energy required to change the state of 1kg of a substance
Specific latent heat of fusion = melting or freezing
Specific latent heat of vaporisation = boiling or condensing

9. Learning Objectives
By the end of this lesson you should…
Be able to describe the change in temperature of a substance as heat energy is supplied or removed
Understand qualitatively and quantitatively the concept of the specific latent heat of a material.
Be able to explain the variation in temperature in terms of intermolecular forces
A jeweller wants to melt 100 g of silver. The specific latent heat of fusion for silver is J/kg. How much energy will be required?
Energy = mass x specific latent heat
m = 100g = 0.1 kg
L = 100,000J/kg
E =mL
E =0.1 x
=10 000J
= 10kJ

10. Learning Objectives
By the end of this lesson you should…
Be able to describe the change in temperature of a substance as heat energy is supplied or removed
Understand qualitatively and quantitatively the concept of the specific latent heat of a material.
Be able to explain the variation in temperature in terms of intermolecular forces
YOUR TASK:
Calculate the energy required to change the temperature of 1kg of ice from -50˚C to 150˚C

11. Temp/OC
150
100 50
-50
210,000J
2,260,000J
420,000J
More energy to boil water than melt it – breaking 2 bonds during melting and rest during boiling.
330,000J
Time/s
210,000J

12. Name that key term... Learning Objectives
By the end of this lesson you should…
Be able to describe the change in temperature of a substance as heat energy is supplied or removed
Understand qualitatively and quantitatively the concept of the specific latent heat of a material.
Be able to explain the variation in temperature in terms of intermolecular forces
Name that key term...

13. The amount of energy required to raise the temperature of 1kg of a substance by 1˚C

14. The temperature at which a substance turns from liquid to gas

15. These are present in solids and liquids but not in gases

16. A picture that uses colour to represent different temperatures

17. The point reached when all temperatures are equal