Final answer:
The standard enthalpy combustion of liquid ethanol is exothermic, meaning that the reaction releases heat energy.
Step-by-step explanation:
The standard enthalpy combustion of liquid ethanol, C₂H5OH, is exothermic. This means that the reaction releases heat energy. In the combustion process, ethanol reacts with oxygen to form carbon dioxide and water. The balanced chemical equation for the combustion of ethanol is:
C₂H5OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O(g)
The combustion of ethanol is exothermic because the products have a lower energy than the reactants. When the reaction occurs, energy is released in the form of heat.