What is produced in a combustion reaction?

In a combustion reaction, the primary products formed are carbon dioxide and water. This type of reaction typically occurs when a hydrocarbon fuel reacts with oxygen. The general equation for a complete combustion reaction of a hydrocarbon can be represented as:

[ \text{C}_x\text{H}_y + O_2 \rightarrow CO_2 + H_2O ]

During combustion, the carbon in the fuel combines with oxygen to form carbon dioxide, while hydrogen combines with oxygen to form water. This process releases a significant amount of energy, which is why combustion reactions are commonly used as a means of generating energy in engines and power plants.

Oxygen gas is a reactant rather than a product; it's consumed during the reaction. A salt could be produced in different types of reactions, such as neutralization, but not specifically in combustion. Sodium chloride is a specific example of a salt produced in a different context (especially in reactions involving acids and bases) and is not a product of combustion reactions. Therefore, the formation of carbon dioxide and water accurately describes the outcome of a combustion reaction, making it the correct answer.