# Do different fuels produce different amounts of energy?

Do different fuels produce different amounts of energy?

## Planning

I am going to investigate the energy released by burning alcohol. I will try to find out how the carbon atoms in each alcohol vary with the energy release.

Alcohols are a series of related organic molecules. The general formula of an alcohol is:

n = number of Carbon atoms

The complete combustion of an alcohol will produce Carbon Dioxide and Water by reacting with Oxygen.

Combustion involves breaking and making chemical bonds. Breaking bonds requires energy input, making bonds releases energy.

In exothermic reaction, the reactants has a higher energy level than the products, the difference is given off as heat energy. In endothermic reaction, the reactants has a lower energy level than the product, the difference is the amount of energy taken in from the surroundings.

I will need to investigate whether different fuels produce different amount of energy. To do this, I am going to do an experiment. I predict that the experiment will be an exothermic reaction and the amount of energy given off per mole of each alcohol will be the same for all the alcohols because:

Energy = mass of water used x specific heat capacity x temperature rise

(j)               (kg)                    J/kg ˚C                          (˚c)

As the mass of water used is known.

That means no matter how much alcohol we burned to increase the temperature of the water, the energy given off will stays the same according to the formula.

Apparatus

• Spirit burners (containing ethanol, propanol, butanol, pentanol, hexanol)
• Heat proof mats
• Clamps and stands
• ...