Concept:Incomplete combustion occurs when a hydrocarbon burns in a limited supply of oxygen.
Explanation:When oxygen is insufficient, hydrocarbons do not burn completely.
Instead of producing only carbon dioxide, they produce carbon monoxide and carbon soot.
Water is still formed during the reaction.
Carbon monoxide is written as
CO.
Carbon soot is elemental carbon, written as
C.
Carbon dioxide,
CO2, is mainly the product of complete combustion.
Therefore, the products formed are I (carbon monoxide) and III (soot).
Answer:C. I and III only