New
New
Year 10
AQA
Higher

Calculating specific heat capacity (∆ E = m c ∆ θ)

I can make calculations using the equation ΔE = mcΔΘ.

New
New
Year 10
AQA
Higher

Calculating specific heat capacity (∆ E = m c ∆ θ)

I can make calculations using the equation ΔE = mcΔΘ.

Lesson details

Key learning points

  1. Energy transferred to increase the temperature of a substance by heating by a fixed amount is proportional to mass.
  2. Energy transferred to a substance by heating a fixed amount is proportional to the increase in temperature.
  3. Energy transferred to increase the temperature of a substance by heating is proportional to its specific heat capacity.
  4. Specific heat capacity equals the energy transferred to/by 1 kg of a material when its temperature changes by 1ºC.
  5. Specific heat capacity, c, is measured in joules per kilogram per degree Celsius.

Common misconception

Often, after teaching, pupils often do not understand what specific heat capacity means.

Discuss the size of a substance’s specific heat capacity in terms of how hard it is to heat up a certain mass of the substance and of how much energy needs to be transferred to heat it up.

Keywords

  • Specific heat capacity - The change in internal energy when the temperature of 1 kg of the material changes by 1°C.

  • Joules/kilogram/degree C - The unit for the specific heat capacity of a material.

Provide pupils with examples of exam questions to practise so that they become familiar with thinking about specific heat capacity in a range of different contexts.
Teacher tip

Equipment

None required.

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

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6 Questions

Q1.
Which of the following is the correct unit used for temperature change?
Fahrenheit (F)
Celsius (C)
degrees (°)
Correct answer: degrees Celsius (°C)
joules (J)
Q2.
Why does having thick carpets help people save money on heating bills?
Heat rises to the top of a house.
Correct answer: They are poor thermal conductors and reduce heat loss to the ground.
They are good thermal conductors.
They are much more comfortable than hard surfaces.
This is the only place energy can escape from a house.
Q3.
Which of the following is the correct unit for specific heat capacity?
J
J/°C
J/kg
°C/kg
Correct answer: J/kg/°C
Q4.
Three identical kettles are used to heat water from the same starting temperature. Kettle A contains 0.5 kg, kettle B contains 1.0 kg and kettle C contains 1.5 kg. Which statements are correct?
All the kettles will boil at the same time.
Correct answer: Kettle A will boil first.
Kettle C will boil first.
Kettle A will boil last.
Correct answer: Kettle C will boil last.
Q5.
Which of the following has the largest store of thermal energy?
A glass of fizzy pop at a temperature of 4°C.
A cup of tea at a temperature of 80°C.
A bath full of cold water at 5°C.
A bath full of warm water at 20°C.
Correct answer: A bath full of hot water at 30°C.
Q6.
A small piece of red-hot metal is dropped into a large bucket of water. Which of the following statements are correct?
Correct answer: The temperature of the metal changes more than the temperature of the water.
The temperature of the metal changes less than the temperature of the water.
The temperature change of the metal and water are equal.
Correct answer: The water and metal will eventually reach the same temperature.
The water will all boil and evaporate.

6 Questions

Q1.
Match the following key words or phrases to their definition.
Correct Answer:specific heat capacity,change in energy of 1 kg of a material when it is heated by 1°C

change in energy of 1 kg of a material when it is heated by 1°C

Correct Answer:joules,the unit of energy

the unit of energy

Correct Answer:kilogram ,the unit of mass

the unit of mass

Correct Answer:degree Celsius,a unit of temperature

a unit of temperature

Correct Answer:joules / kilogram /degree Celsius,the unit of specific heat capacity

the unit of specific heat capacity

Q2.
Which of the following is the energy required to heat an object and change its temperature directly proportional to?
Correct answer: mass
Correct answer: change in temperature
starting temperature
Correct answer: specific heat capacity
starting energy
Q3.
Water has a specific heat capacity of 4200 J/kg/°C, calculate the energy required to increase the temperature of 1.5 kg of water from 30°C to 80°C.
140 kJ
189 kJ
210 kJ
Correct answer: 315 kJ
504 kJ
Q4.
A heater increases the temperature of samples of different materials by 10°C. The masses and energy required are shown. Starting with the greatest, sort them in order of specific heat capacity.
1 - mass: 200 g; energy required: 900 J
2 - mass: 200 g; energy required: 300 J
3 - mass: 100 g; energy required: 100 J
4 - mass: 100 g; energy required: 50 J
5 - mass: 400 g; energy required: 100 J
Q5.
A sample of a new plastic has a mass of 250 g. When provided with 6.0 kJ, its temperature increases from 20°C to 50°C. Calculate the specific heat capacity of the sample.
0.8 J/kg/°C
50 J/kg/°C
500 J/kg/°C
Correct answer: 800 J/kg/°C
8000 J/kg/°C
Q6.
In a test, a 500 g sample of a liquid with specific heat capacity of 1500 J/kg/°C is heated with 60.0 kJ of energy. The starting temperature of the sample was 5.5°C. Calculate the final temperature.
7.5°C
40.0°C
45.5°C
80.0°C
Correct answer: 85.5°C