Determining the specific heat capacity of a metal

• There are different ways to investigate methods of insulation. In this required practical activity, it is important to:

  • make and record potential difference, current and time accurately
  • measure and observe the change in temperature and energy transferred
  • use appropriate apparatus and methods to measure the specific heat capacity of a sample of material
• Aim of the experiment

  to measure the specific heat capacity of a sample material
• Method

  1. Place immersion heater into central hole at top of block.
  2. Place thermometer into smaller hole and put couple of drops of oil into hole to make sure thermometer is surrounded by hot material.
  3. Fully insulate block by wrapping loosely with cotton wool.
  4. Record temperature of block.
  5. Connect heater to power supply and turn on for ten minutes taking note of ammeter and voltmeter readings.
  6. After ten minutes temperature will still rise even though heater has been turned off and then will begin to cool. Record highest temperature it reaches and calculate temperature rise during experiment.
• The actual value for the specific heat capacity of aluminium is 900J/kg°C
• Evaluation

  • Not all of the heat from the immersion heater will be heating up the aluminium block, some will be lost to the surroundings
  • More energy has been transferred than is needed for the block alone as some is transferred to the surroundings, the thermometer and the heater itself
  • This causes the calculated specific heat capacity to be higher than for one kilogram (kg) of aluminium alone
• Hazard

  • Hot immersion heater
  • Sample material
• Consequence

  • Burn skin
• Control measures

  • Do not touch when switched on
  • Position away from the edge of the desk
  • Allow time to cool before packing away equipment
  • Run any burn under cold running water for at least 10 minutes