CH4, C3H8 and C5H12 are the hydrocarbons which have substitution reactions. This happens because CH4 (Methane), C3H8 (Propane) and C5H12(Pentane) are all saturated hydrocarbons (alkanes). Substitution reaction, which is a characteristic of saturated hydrocarbons, is the reaction in which one or more hydrogen atoms of a hydrocarbon are replaced by some other atoms (such as chlorine).