Complete combustion of hydrocarbons occurs in the presence of excess oxygen and produces carbon dioxide (CO₂) and water (H₂O) as exclusive products. In incomplete combustion, carbon monoxide (CO) can form, but it is not always guaranteed.

To determine the empirical formula, divide each element’s mass by its atomic mass: C (24 ÷ 12) = 2, H (4 ÷ 1) = 4, O (32 ÷ 16) = 2, giving a 1:2:1 ratio. Thus, the simplest whole-number formula is CH₂O