24 cubic centimetres of water

 

We set up this experiment to show that the chemical energy store in a candle empties and the thermal energy store of the water fills. We had the candle 3cm below the tube and we heated for 2 minutes. We weighed the candle before heating and again after. The mass went down slightly showing that the chemical energy store of the candle had emptied. We measured exactly 24 cubic centimetres of water into the tube and measured the temperature at the beginning and end. The 24 cm^3 was chosen because with that volume, the thermal energy store of the water has increased by 100J for every 1 degree Celsius rise in temperature. Not all of the chemical energy from the candle goes to fill the thermal store of the water. Some is dissipated as thermal energy into the surroundings so just by knowing the energy absorbed by the water, we cannot be sure of the actual energy that left the candle. However, I may have a way of attacking this problem and finding the efficiency.