Required practical 1 - specific heat capacity

equipment needed

• 1 KG block of metal or a beaker containing a known mass of water - substance to calculate the specific heat capacity

• Thermometer to measure the temperature rise of the substance

• Immersion heater to heat the substance

• Power supply to supply power to the heater

• Stopwatch to measure the time taken for the substance to heat up by certain temperature

• Volt meter to determine potential difference to the heater

• ammeter to to determine the current from the power supply to the heater

method

1. Start by assembling the apparatus, placing the heater into the top of the block

2. Measure the initial temperature of the aluminium block from the thermometer

3. Turn on the power supply and start the stopwatch

4. Whilst the power supply is on, the heater will heat up the block. Take several periodic measurements, eg. every 1 minute of the voltage and current from the voltmeter and ammeter respectively, calculating an average for each at the end of the experiment up to 10 minutes

5. Switch off the power supply, stop the stopwatch and leave the apparatus for about a minute. The temperature will still rise before it cools

6. Monitor the thermometer and record the final temperature reached for the block

errors

Systematic Errors:

• Make sure the voltmeter and ammeter are initially set to zero, to avoid zero error

Random Errors:

• Not all the energy transferred from the heater will be transferred to the block, some will be dissipated

  • This means the measured value of the specific heat capacity is likely to be higher than what it actually is

  • To reduce this effect, make sure the block is fully insulated

• A joulemeter could be used to calculate energy directly

  • This would eliminate errors from the voltmeter, ammeter and the stopwatch

• Make sure the temperature value is read at eye level from the thermometer, to avoid parallax error

• The experiment can also be repeated with a beaker of water of equal mass, the water should heat up slower than the aluminium block

safety considerations

• Make sure never to touch the heater whilst it is on, otherwise, it could burn skin or set something on fire

  • Run any burns immediately under cold running water for at least 5 minutes

• Allow time for all the equipment, including the heater, wire and block to cool before packing away the equipment

• Keep water away from all electrical equipment

• Wear eye protection if using a beaker of hot water