# Specific Heat Capacity

In this worksheet, students will learn how heat is stored in objects and how to calculate how much heat is stored in an object.

Key stage:  KS 4

Curriculum topic:  Physics: Energy

Curriculum subtopic:  Calculating Energy Efficiency for Energy Transfers

Difficulty level:

### QUESTION 1 of 10

Particles are vibrating all of the time, moving around all over the place and bashing into their neighbouring particles. We have a special scientific term for this, we call it heat - I know, super technical word you’ve never come across before. This is literally all that heat is just movement (or vibration) of particles. This means that e can get stuff really hot here on earth, did you know that the hottest place in the solar system is not the sun, but a place called JET in Oxford! Its reached temperatures of over 50 million degrees – that over 20 times the temperature of the sun.

Okay, so we know that when we get stuff really hot all we are really doing is making the particles move around more – but did you know that some particles are harder to make move than others? Anyone who has put a pot of water on the stove to boil will tell you it takes AGES, but what about making a chunk of metal reach this same temperature? Well, it takes much less time thanks to something we call the specific heat capacity (or SHC for short).

SHC is literally just a measurement of the amount of energy it takes to heat up 1kg of a material by 1OC and it has the unit of (are you ready for this) -  joule per kilogram degree Celsius (J/kg °C).We can work this out by using the following equation:

energy transferred = mass × specific heat capacity × temperature change

To be really helpful, you will NOT need to remember this equation in the exam – you’ll just need to make sure that you can remember which number is which!

So, let’s go through an example question and how you might answer it:

A block of Aluminium has a specific heat capacity of 900J/kg oC and is heated from a starting temperature of 0 to a final temperature of 100oC. The mass of the block is 4kg. How much energy is transferred to the object?

You can answer a question like this in stages:

1 – find all of the numbers and underline them like this:

A block of Aluminium has a specific heat capacity of 900J/kg oC and is heated from a starting temperature of 0 to a final temperature of 100oC. The mass of the block is 4kg. How much energy is transferred to the object?

2 – good, now we need to find out where they all fit into the equation. I write them out and put the corresponding number next to them like this:

Mass = 4kg

Specific Heat Capacity = 900 J/kg oC

Temperature change = 0 – 100.

3 – Oh no! There is a temperature change, so work out what the difference is (super hard right?)

Mass = 4kg

Specific Heat Capacity = 900 J/kg oC

Temperature change = 100 – 0 = 100 oC

4 – finally, write them into the equation, put the numbers in the calculator and press =.

Energy = 4 x 900 x 100

Energy = 360,000 J

Don’t forget your units! And make sure you ALWAYS write out every step – this way the examiner can follow what you are thinking and might be able to give you some marks even if you don’t get the answer right.

What happens to the particles when you cool them down?

They vibrate more

They vibrate less

Nothing

Match the following measurements to their units.

## Column B

Energy
Degrees Celsius (oC)
Mass
Joule (J)
Temperature
Kilogram (kg)
Specific Heat Capacity
Joules per kilogram degrees Celsius (J/kgo

What is the correct definition for Specific Heat Capacity?

a measurement of the amount of energy it takes to heat up 1kg of a material.

a measurement of the amount of energy is needed to change from a liquid to a gas.

a measurement of how much energy is used to heat up water

a measurement of the amount of energy it takes to heat up 1kg of a material by 1OC

Is the following statement true or false?

A substance with a higher specific heat capacity takes more energy to heat up.

true

false

A 2kg block of aluminium is heated from 20<sup>o</sup>C to 80<sup>o</sup>C. How much energy is transferred in this heating experiment?

Specific heat capacity of aluminium = 900J /kg <sup>o</sup>C.

energy transferred = mass × specific heat capacity × temperature change

1kg of water is raised from 20<sup>o</sup>C to its boiling point, how much energy is used to do this?

Specific heat capacity of water = 4200J /kg <sup>o</sup>C.

Which will take more energy to heat up, 1kg of water or 1kg of lithium?

Specific heat capacity of water = 4200J /kg oC.

Specific heat capacity of lithium = 3.56J /kg oC.

Water

Lithium

Mercury has a specific heat capacity of 140 J/kg °C. Calculate the energy transferred in kJ when 50kg of mercury is heated from 20°C to 25°C

A skyscraper has 450,000,000 kg of steel in it. During the night the steel falls to a temperature of 10<sup>o</sup>C but in the peak midday sun, it has a high of 32<sup>o</sup>C.

If the steel has a specific heat capacity of 510J /kg <sup>o</sup>C, how much energy does the steel gain from the sun? Give your answer in Mega Joules.

energy transferred = mass × specific heat capacity × temperature change

Do the following items need a high or low specific heat capacity to be good at their jobs?

 High SHC Low SHC Frying Pan Wall Insulation Metal Heating Wire Plants Butter
• Question 1

What happens to the particles when you cool them down?

They vibrate less
EDDIE SAYS
Heat energy is stored as the movement of particles, so if you have more heat then that is more movement of those particles. Int he same way if there is less heat then the particles will move less. Always make sure you read the question thoroughly.
• Question 2

Match the following measurements to their units.

## Column B

Energy
Joule (J)
Mass
Kilogram (kg)
Temperature
Degrees Celsius (oC)
Specific Heat Capacity
Joules per kilogram degrees Celsi...
EDDIE SAYS
Thermal energy flows from hot to cold.
• Question 3

What is the correct definition for Specific Heat Capacity?

a measurement of the amount of energy it takes to heat up 1kg of a material by 1OC
EDDIE SAYS
Whilst you don't need to remember the equation as it will be given to you in the exam, you will need to remember all of the definitions. This means that you will have to remember this definition.
• Question 4

Is the following statement true or false?

A substance with a higher specific heat capacity takes more energy to heat up.

true
EDDIE SAYS
Specific Heat Capacity is a measurement of the amount of energy it takes to heat up a substance - this means that if it has a higher specific heat capacity it will take more energy to heat it to the same temperature as another substance with a lower specific heat capacity.
• Question 5

A 2kg block of aluminium is heated from 20<sup>o</sup>C to 80<sup>o</sup>C. How much energy is transferred in this heating experiment?

Specific heat capacity of aluminium = 900J /kg <sup>o</sup>C.

energy transferred = mass × specific heat capacity × temperature change

108000
EDDIE SAYS
mass = 2kg change in temperature = 80 - 20 = 60oC Specific heat capacity = 900J /kg oC. Energy = 2 x 900 x 60 Energy = 108000 J
• Question 6

1kg of water is raised from 20<sup>o</sup>C to its boiling point, how much energy is used to do this?

Specific heat capacity of water = 4200J /kg <sup>o</sup>C.

336000
EDDIE SAYS
mass = 1kg change in tempurature = 100 (boiling point of water) - 20 = 80 oC Specific heat capacity= 4200J /kg oC. Energy = 1 x 4200 x 80 Energy = 336000 J
• Question 7

Which will take more energy to heat up, 1kg of water or 1kg of lithium?

Specific heat capacity of water = 4200J /kg oC.

Specific heat capacity of lithium = 3.56J /kg oC.

Water
EDDIE SAYS
The higher the specific heat capacity, the more energy it takes to heat it up. You could try and work it out of just look at the specific heat capacity - the one with the highest will always take the most energy. Love those cheat methods!
• Question 8

Mercury has a specific heat capacity of 140 J/kg °C. Calculate the energy transferred in kJ when 50kg of mercury is heated from 20°C to 25°C

35
EDDIE SAYS
mass = 50 Specific heat capacity = 140J /kg oC change in termpurature = 25 - 20 = 5oC Energy transferred = 50 x 140 x 5 = 35 000 J then you need to convert this to kJ (kilojoules) so divide it by 1000. 35000/1000 = 35kJ You would still get some marks for writing 35000, just not full makes, so don't feel too bad if you forgot to convert it to kJ.
• Question 9

A skyscraper has 450,000,000 kg of steel in it. During the night the steel falls to a temperature of 10<sup>o</sup>C but in the peak midday sun, it has a high of 32<sup>o</sup>C.

If the steel has a specific heat capacity of 510J /kg <sup>o</sup>C, how much energy does the steel gain from the sun? Give your answer in Mega Joules.

energy transferred = mass × specific heat capacity × temperature change

275400
275,400
EDDIE SAYS
Don't be put off by the situation the question has been framed in, just look for the numbers and follow the path that has been laid out for you. mass = 450,000,000 kg SHC = 510J /kg oC change in temperature = 32 - 10 = 12 oC Energy = 450,000,000 x 510 x 12 Energy = 2.754x1011 Energy in MJ = 2.754x1011 / 1,000,000 Energy in MJ = 275,400
• Question 10

Do the following items need a high or low specific heat capacity to be good at their jobs?