Thursday, 16 June 2016

Energy released from fuels

Equipment

Spirit burners with different fuels in (e.g. Ethanol, Propanol, Butanol)
Top pan balance (0.01g accuracy)
Boiling tube
Clamp and stand
Thermometer
Stopclock
Measuring cylinder
Goggles

Method

Place 50ml of water into the boiling tube and place into the clamp. Measure the water temperature.
Place spirit burner on the balance and record the initial mass.
Next place the spirit burner under the boiling tube, light it and start the stop clock, ensuring that the tip of the flame is just beneath the boiling tube.
After 2 minutes have passed snuff out the spirit burner and record the temperature of the water.
Place spirit burner on the balance and record the final mass.
Repeat this twice more using a fresh boiling tube and fresh water and then calculate the average temperature rise divided by the average change in mass.
Repeat the whole experiment three times for each fuel.

Risk assessment

Care should be taken with the spirit burner to ensure you do not spill any fuel. Goggles should be worn when heating liquids. When replacing the boiling tube take care as it will be hot - it should be left in a test tube rack to cool slowly so as not to crack the glass.