Which compound is produced during the incomplete combustion of alkanes along with carbon monoxide?

During the incomplete combustion of alkanes, several products can be formed, but carbon and carbon monoxide are common byproducts. Incomplete combustion occurs when there is not enough oxygen available to fully convert the alkane into carbon dioxide and water. Instead, some of the carbon atoms in the alkane do not completely oxidize and result in the formation of solid carbon, often referred to as soot.

When considering the reaction of alkanes with limited oxygen, the general outcome leads to carbon monoxide (which is a result of partial oxidation) and elemental carbon (the solid form). Water is typically also produced, but the question specifically asks for a compound produced alongside carbon monoxide, making carbon the more relevant answer in this context.

Thus, the presence of carbon in addition to carbon monoxide underlines the conditions of insufficient oxygen during the reaction, highlighting the incomplete nature of the combustion process.