Physics

An experiment to measure the enthalpy change of combustion for four different fuels; methanol, ethanol, propan-1-ol and butan-1-ol.

In this experiment we lit a spirit burner underneath a beaker of water and heated for a sufficient length of time. Our results showed us the enthalpy change of combustion for each spirit burner.

Method

• 50cm³ of water was placed into a 100cm³ beaker. This beaker was supported by a tripod and gauze mat.

• A thermometer was placed into the beaker and held upright by a clamp and stand with the bulb of the thermometer in the centre of the water.

• A spirit burner was placed underneath the beaker on the tripod and on a heat proof mat. The mass of the spirit burner was recorded at the start of the experiment.

• The temperature of the water at the start of the experiment was taken and recorded.

• The wick on the spirit burner was lit and a draught screen placed around it, concluding in the spirit being burned and the water being heated.

• When the water had heated up an appreciable amount the flame was blown out and the final temperature of the water was measured and recorded.

• The final mass of the spirit burner was measured and recorded.

Results

Alcohol in spirit burner methanol ethanol Propan-1-ol Butan-1-ol

Volume of water placed in calorimeter/cm³ 50 50 50 50

Mass of water placed in calorimeter/cm³ 50 50 50 50

Temperature of water at the start/K 17.5 19.0 28.5 35.5

Temperature of water at the end/K 24.5 35.5 45.0 46.5