What are the reactants of the combustion of ethanol?

The correct response identifies that the reactants in the combustion of ethanol are ethanol (C2H5OH) and oxygen (O2). In a combustion reaction, a fuel (in this case, ethanol) reacts with oxygen to produce energy along with combustion products, typically carbon dioxide (CO2) and water (H2O).

During the combustion process, the carbon and hydrogen atoms in ethanol combine with oxygen from the air. The general equation for the complete combustion of ethanol can be represented as follows:

C2H5OH + 3O2 → 2CO2 + 3H2O + energy

This shows that for combustion to occur, both the fuel and oxygen must be present as reactants. Other choices do not accurately represent the necessary components involved in the initial reaction phase leading to the release of energy. For example, while carbon dioxide and water are products of the combustion reaction, they cannot be classified as reactants. Similarly, energy is a result of the reaction rather than a reactant itself.