Which substances are involved in the combustion of ethanol?

The correct answer identifies the substances that react during the combustion of ethanol. When ethanol (C2H5OH) burns, it undergoes a chemical reaction with oxygen (O2) in the presence of heat. This reaction produces carbon dioxide (CO2) and water (H2O) as products, along with releasing energy in the form of heat and light.

In the case of combustion, both ethanol and oxygen are necessary to initiate and sustain the reaction. Ethanol serves as the fuel, while oxygen acts as the oxidizer that facilitates the combustion process. Without both of these substances, combustion cannot occur.

It is also essential to note that the products of the combustion reaction, carbon dioxide and water, do not directly participate in the reaction but are formed as a result of the combustion process. This differentiates them from ethanol and oxygen, which are the reactants involved in the initiation of combustion. Hence, ethanol and oxygen are the primary substances that need to be present for combustion to occur, making the specified answer accurate.