Final answer:
When enough heat energy is absorbed by liquid ethanol, it undergoes evaporation and changes to a gas state.
Step-by-step explanation:
When enough heat energy is absorbed by liquid ethanol, the change of state that will occur is evaporation. Evaporation is the process in which a liquid changes into a gas state by gaining heat energy. As the liquid ethanol absorbs enough heat energy, its molecules gain kinetic energy and overcome the intermolecular forces holding them together, resulting in the transition from a liquid to a gaseous state.