IBDP chemistry Mandatory Experiment on Enthalpy of Combustion of Ethanol
To determine the enthalpy of combustion of ethanol experimentally using metal can and method of specific heat capacity.
specific heat capacity is defined as the heat require to raise temperature of 1 gram of a substance by 1 Kelvin.
where q is heat supplied,
m= mass of water,
∆T= change in temperature
Ethanol( 100 g)
spirit lamp/burner with thread (1)
copper can or cold drink can or aluminium can or glass beaker) (1)
clamp stand (1)
0 – 50 °C thermometer (1)
100 cm3 measuring cylinder (1)
weighing balance (0.01 g accuracy)
Safety glasses or Eye protection
1. Record the Weight of the spirit lamp filled with ethanol along with its lid so the ethanol is not evaporated.
2. Measure 100 cm3 water by using measuring cylinder and pour it into the metal can.
3. Fix the experimental set up as required.
4. Use the thermometer to Measure and record the initial temperature of the water in the can.
5. Now light the spirit lamp and start heating the water sample.
6. Use thermometer to stir the water to evenly distribute the heat .
7. Measure the weight of spirit lamp along with ethanol to record the mass of ethanol burned to heat water.
Safety and health caution: Ethanol is highly flammable so keep it safe. Wear safety glasses. Always Use lab coat always to keep your clothes protected.
Use the Raw Data to get the processed data with the help of specific heat capacity formula q=mc∆T.
So for example 0.3 g of ethanol had been burned and the temperature of the water had risen by 1o °C.
Hence q= 4.18 x 0.10 x 10 = 4.18 kJ
The heat evolved on burning 0.3 g of ethanol = 4.18 kJ
Molar mass = 2×12 + 6×1 + 16 = 46 g
You can now determine the heat evolved on burning 1 mole of ethanol.
0.3 g =4.18 kJ
46 g =4.18 x 46/0.3
= 640.9 kJ
Thus with the above IBDP chemistry Mandatory Experiment on Enthalpy of Combustion of Ethanol , you can learn the Energetic topic very well.