application of substitution reaction ?

Those reactions in which an atom or group of atoms of a compound is replaced by other atom or group of atoms are called substitution reactions. Substitution reaction has various applications. Saturated hydrocarbons are less reactive and do not react with most reagents. Substitution reactions help to form different compounds which can be used for further reactions. Here a particular example of reaction of chlorine with methane is taken. On complete replacement of all hydrogen atoms with chlorine atoms carbon tetrachloride is formed.