Required Practical 14: Specific Heat Capacity
About this practical...
The specific heat capacity of a material links the amount of energy needed to raise its temperature per kg. Rather than simply completing a calculation, you will measure the mass of the substance, measure the change in temperature and calculate the energy input. After calculating the specific heat capacity, your value will differ from the official number, look at ways that you could improve the experiment.
Method:
1. Collect all of the equipment and set it up on your bench.
2. Check the circuit diagram, voltmeter is parallel and ammeter in series.
3. Find the mass of your metal block and record the initial temperature.
4. Start the clock at the same time that you turn on the power supply
5. Every 60 seconds, record the potential difference from the voltmeter and the current from the ammeter.
6. After 10 minutes, turn off the power and record the final temperature. Leave the equipment to cool down.
7. Calculate the mean voltage and mean current recorded.
8. Use the equations to calculate the energy input: Power = voltage x current also use Energy = power x time
9. Now use the value of the energy input along with the mass of the block and the change in temperature to find the specific heat capacity of the block.
Extension - find out the official value and explain why your value was different. You can then design another method that would give you an answer that is closer to this official value.
Safety & Managing Risks
Usual lab rules must be followed: Bags and stools tucked away and notify the teacher of any breakages immediately. Take care with sources of electricity. The heaters will remain hot for some time, do not touch while hot, ask for help. When hot, the heaters expand and may become stuck in the metal blocks, do not try to pull them out. Don't pull the heaters by their wires. For more detailed information, please consult CLEAPSS.
Technician notes:
Selection of metal cylinders with heater and thermometer holes pre-drilled
Heating elements
Ammeters
Voltmeters
Powerpacks (limited to 6V)
Wires
Timers
Thermometers
This page was updated on: 8th January 2022