What is complete combustion?

Complete combustion refers to a chemical reaction in which a fuel reacts completely with an oxidizing agent, typically oxygen, to produce carbon dioxide and water as the primary products. When complete combustion occurs, it signifies that all the fuel has been fully utilized in the reaction, ideally leading to no leftover fuel and minimal byproducts such as carbon monoxide or unburned hydrocarbons.

In this context, the correct answer indicates that complete combustion involves burning all fuel using more than the theoretical amount of air. This implies that sufficient oxygen is provided for the fuel to react completely. While theoretically, the precise stoichiometric ratio of air is needed, in practical applications, it is common to provide a surplus of air to ensure all fuel is combusted thoroughly. This surplus eliminates the potential for incomplete combustion, which can produce undesirable pollutants and decrease efficiency.

In contrast, the other statements do not align with the definition of complete combustion. The option suggesting the use of the exact amount of air describes stoichiometric combustion, which can lead to incomplete combustion if there are any variations in conditions. The choice referring to creating smoke without air is inaccurate because smoke indicates incomplete combustion, and combustion cannot occur without oxygen. Finally, burning fuel to waste without efficiency does not encapsulate the principles of