1.1.8 Required Practical: Investigating SHC

• Aim of the Experiment

  To determine the specific heat capacity of a material by measuring the amount of energy supplied to it and the corresponding temperature change
• Equipment Needed

  • A solid metal block
  • An electric immersion heater
  • A thermometer
  • A power supply
  • A joulemeter (or an ammeter, voltmeter, and stopwatch)
  • Insulation material
  • A balance
  • A stopwatch
• Method

  1. Measure the mass

  2. Set up the apparatus

  3. Record the initial temperature

  4. Heat the block

  5. Record the final temperature

  6. Energy measurement

  7. Calculate the specific heat capacity

  8. Repeat and average
• Measure the Mass

  Measure the mass of the metal block using a balance and record it in kilograms (kg)
• Set Up the Apparatus

  1. Place the immersion heater into the metal block's hole

  2. Insert the thermometer into the other hole

  3. Wrap the metal block in insulation

  4. Connect the immersion heater to the power supply and the joulemeter
• Initial Temperature

  Record the initial temperature of the metal block before switching on the heater
• Heat the Block

  1. Turn on the power supply to start heating the block

  2. Continue heating until the temperature rises by about 10-15°C

  3. Record the final temperature
• Energy Measurement

  1. If using a joulemeter, record the total energy supplied directly

  2. If using a voltmeter and ammeter, calculate power and multiply by time to get energy supplied
• Calculate the Specific Heat Capacity

  Use the formula: c=EmΔT
• c is the specific heat capacity in joules per kilogram per degree Celsius (J/kg°C)
• E is the energy supplied (in joules, J)
• m is the mass of the block (in kilograms, kg)
• ΔT is the temperature change (in degrees Celsius, °C)
• Repeat and Average

  For accuracy, repeat the experiment at least twice more and take the average of the calculated specific heat capacities
• The temperature change ΔT is: ΔT=30−20=10 °C
• Using the formula: c=8400 J2 kg×10 °C=420 J/kg°C
• The specific heat capacity of the material is 420 J/kg°C
• Sources of Error and How to Minimize Them

  • Energy loss to the surroundings
  • Inaccurate temperature measurement
  • Energy measurement errors
• Minimize energy loss by using better insulation and conducting the experiment quickly
• Ensure the thermometer is placed correctly and is sensitive enough to detect small changes
• Ensure the joulemeter is calibrated correctly, or take consistent readings and minimize delays in recording time