During a chemical reaction, bonds are broken in the reactants and new bonds are formed in the products. The energy required to break and make bonds is also called enthalpy. Combustion (or burning) reactions are examples of exothermic reactions; in these chemical reactions more energy is released when making the bonds in the products than is taken when breaking the bonds in the reactants. Consequently exothermic reactions transfer energy to the surroundings. Enter the experiment to collect data of water temperature and alcohol mass during the combustion of different alcohols and then determine their enthalpy of combustion.