Exam Date -
L/O :- To understand and be able to calculate specific heat capacity
It is easy to measure how hot something is by using a thermometer. It is much more difficult to measure how much heat energy is in something. However, we can measure how much energy is put into something.
The amount of energy it takes to heat up 1kg of a substance by
1˚C is called the specific heat capacity of a substance
How could you test which liquid has the highest thermal capacity?
A 50 watt heater can be placed into liquids. The heater transfers
50 J of energy every second. How could you use this to work out which liquid has the highest specific heat capacity
Remember the more energy the liquid needs to heat it up, the higher the specific heat capacity
What variables will you need to control to make sure the results are accurate?
1 Kg of liquid
Which had the highest thermal Capacity?
Can you explain why??
09/04/2020
How could you test the thermal conductivity of a metal like aluminium or copper?
You can work out the energy you will need to heat something using the equation
Energy (J) = Mass (Kg) x Specific Heat capacity x Change in Temp (˚C)
Energy (J)
Mass (Kg)
E = m x c x θ
Specific Heat
Capacity (J/Kg˚C)
Change in
Temp (˚C)
Specific Heat
Capacities
• Aluminium 0.9
• Copper 0.39
• Lead 0.13
• Ethanol 2.44.
• Water 4.18
Which of these would require the most energy?
1) Heating 10Kg of Aluminium to increase by 4˚C
2) Heating 5.8 Kg of Copper from 15˚C 25˚C
3) Heating 5Kg of water from 6˚C 10˚C
Radiators use water to heat a house. Water has a high specific heat capacity (4.18 J/ Kg˚C ). So it heats up quickly but it also loses heat quickly
Storage heaters use concrete. Concrete has a low specific heat capacity (0.18 J/ Kg˚C ). These means that they heat up slowly but release their heat over a long period of time
What are the advantages and disadvantages of using storage heaters?
Some materials heat up faster than others
The amount of energy it takes to heat up 1kg of a substance by
1˚C is called the specific heat capacity of a substance
Water has a high specific heat capacity. Concrete has a low specific heat capacity
Energy (J) = Mass (Kg) x Specific Heat capacity x Change in Temp (˚C)
E = m x c x θ
The oceans are often said to be really important in regulating the world temperature. How does what you have learned today help you to explain this?
09/04/2020
• Can you explain what specific heat capacity is?
• Can you explain how to measure the amount of energy given to a substance?
• Can you work out how much energy will be needed to heat a substance by a certain temperature?