Fuels and alcohols

• A fuel is something which burns to produce energy
• Combustion is when fuel is burnt and reacts with oxygen to produce energy
• Exothermic reaction is when a reaction gives out heat energy . The temperature will increase. Eg combustion and hand warmers. Products have LESS energy than reactants
• Endothermic reactions is one which absorb out heat energy. The temperature will decrease. Eg cold packs. Products have MORE energy that reactants
• What is the formula for an alcohol?

  CnH2n+1OH
• What is the equation to work out the energy realeased?

  Eh - cm triangleT
• Alcohols are often used as solvents
• As alcohol increase in size their melting and boiling points increase due to the increasing strength of intermolecular forces.
• Alcohols make good fuels due to their high flammability and because they burn with a clean flame
• The boiling points of the alcohols increase as the number of carbon atoms in the molecules increase. The longer the hydrocarbon chains the greater the forces of attraction between molecules. This means more energy will be required to seperate bigger molecules and so boiling points will increase.