When a compound containing C H and O is completely combusted in air what reactant besides the hydrocarbon is involved in the reaction?

When a compound containing carbon (C), hydrogen (H), and oxygen (O) is completely combusted in air, the primary reactant besides the hydrocarbon is oxygen (O₂) from the air. During combustion, the carbon in the hydrocarbon reacts with oxygen to form carbon dioxide (CO₂), while the hydrogen reacts with oxygen to produce water (H₂O). This process releases energy in the form of heat and light.