Maths for Chemists
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I have done an experiment to measure the enthalpy of combustion of some alcohols. If I have calculated the energy transferred to the water, the number of moles of fuel burnt and the mass of one mole of fuel, how do I calculate the enthalpy of combustion?
Do I multiply the energy transferred to the water by the mass of one mole of fuel and then dividing this by the mass of fuel burnt or some other way around?
A good way to approach this type of question is to look at the units of the answer you are looking for. Here you are trying to calculate the enthalpy of combustion of an alcohol in kJ mol-1.
So you will get the answer by dividing the energy transferred to the water by the amount of fuel burnt in moles.
You have worked out the energy transferred to the water.
Amount of fuel burnt (mol) = Mass of fuel burnt (g)/Molar mass of fuel (g mol-1)
Orion
Risk assessment
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updated: 27 November 2003
