Specific Heat Capacity - Todmorden High...

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Specific Heat Capacity

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Temperature and kinetic energy


Heat and temperature

The heat energy stored in a material may be thought of as

the total kinetic energy of all the particles.

Compared to a spark, the particles in a bath of

water move slowly, so it has a relatively low

temperature, but there is a large amount of

energy stored since there are many particles.

Which contains more heat energy: a bath of hot water or a

small spark from a fire?

The particles in a spark from a fire move

around very quickly, so it has a high

temperature. However, there are only a few

particles, so it has very little stored heat energy.


Investigating temperature change


What factors affect temperature change?


How does energy affect materials?

Do different materials need the same amount of energy to

increase their temperature by the same amount?

To increase the

temperature of 1kg

of water by 1 °C,

requires 4200J.

To increase the

temperature of 1kg

of copper by 1 °C,

requires 390J.

Water and copper require different amounts of energy because

they have different values for a property called specific heat

capacity (SHC). SHC is the amount of energy required to

increase the temperature of 1kg of a material by 1°C.

So, the specific heat capacity for water is 4200J/kg°C

and for copper is 390J/kg°C.


Factors affecting temperature change


What is specific heat capacity?

The specific heat capacity of a material is the amount of

energy required to raise 1kg of the material by 1 °C.

Energy is measured in joules (J).

It can be used to work out how much energy is needed to

raise the temperature of a material by a certain amount:

energyspecific heat

capacitytemperature

change= mass × ×

Mass is measured in kilograms (kg).

Temperature change is measured in °C.

Specific heat capacity is measured in J/kg°C.


Specific heat capacity example

How much energy is needed to

increase the temperature of 600g

of water by 80°C in a kettle?

energy = 0.6kg × 4,200J/kg°C × 80°C

= 201,600J

Note: mass = 600g = 0.6kg and

the specific heat capacity

of water is 4,200J/kg°C.

energyspecific heat

capacitytemperature

change= mass × ×


Choosing suitable materials

Different materials have different specific heat capacity

values. A high value means that the material can store a large

amount of heat energy for a minimal temperature change.

For example, concrete is used in night

storage heaters. Concrete has an SHC

of 880J/kg°C. This is high compared

with other suitable materials such as

granite (SHC = 790J/kg°C).

Radiators use closed liquid systems.

Water is used because it has an extremely

high SHC of 4200J/kg°C. This is much

higher than oil, for example, with a typical

SHC of 1800J/kg°C.


Specific heat capacity of metals


The specific heat capacity equation


Specific heat capacity calculations


Glossary


Multiple choice quiz

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