Which fuel is better?

Decide which is the better fuel to use for boiling water, and hence which fuel to take with you on the expedition.

Equipment 

• Old tin cans
• Beakers
• Thermometers
• Tripods
• Gauzes
• Heat-resistant mats
• Measuring cylinders
• Clamp stands
• Woodblocks
• Aluminium foil
• Metre rulers
• Stop clocks
• Top-pan balances
• Two solid fuels

Health, safety and technical notes

• Read our standard health and safety guidance here.
• Wear eye or clothing protection if desired.
• This is an open-ended problem solving activity, so the guidance given here is necessarily incomplete.
• Two solid fuels are needed for comparison, eg charcoal for barbecues and paraffin or candle wax.
• Ensure students use only small quantities of fuel.
• Warn students that the fuel containers will become very hot – therefore do not touch.
• You need to check the current hazard classification of any fuel tablets, including their appropriate disposal. Some tablets absorb moisture from the air and can spit alarmingly when ignited.
• Paraffin wax is of low hazard, but for other solid fuels the manufacturer’s safety data sheet should be consulted.

Possible approaches

Learners must consider all the variables that they are going to control in the experiment in order to make a fair comparison. They must also ensure that the fuel is safely contained. Used tin cans are very good for this as they are easy to come by, and can be regarded as disposable. More advice on how to use these resources can be found here.

Possible extension

How would you improve this experiment if you were doing it again?