Import Question JSON

$\text{Hint: Chlorination of methane proceeds via a free radical chain mechanism.}$ $\text{The whole reaction takes place in the given three steps.}$ $\text{Step 1: Initiation:}$ $\text{The reaction begins with the homolytic cleavage of Cl – Cl bond as:}$ $\text{Cl – Cl} \xrightarrow{h\nu} \text{Cl} \cdot + \text{Cl} \cdot$ $\text{Chlorine free radicals}$ $\text{Step 2: Propagation:}$ $\text{In the second step, chlorine-free radicals attack methane molecules and}$ $\text{break down the C–H bond to generate}$ $\text{methyl radicals as:}$ $\text{CH}_4 + \text{Cl} \xrightarrow{h\nu} \text{CH}_3 + \text{H – Cl}$ $\text{Methane}$ $\text{These methyl radicals react with other chlorine-free radicals to form methyl}$ $\text{chloride along with the liberation of a}$ $\text{chlorine-free radical.}$ $\text{CH}_3 + \text{Cl – Cl} \rightarrow \text{CH}_3 – \text{Cl} + \text{Cl} \cdot$ $\text{Methyl chloride}$ $\text{Hence, methyl-free radicals and chlorine-free radicals set up a chain}$ $\text{reaction. While HCl and CH}_3\text{Cl are the major}$ $\text{products formed, other higher halogenated compounds are also formed as:}$ $\text{CH}_2\text{Cl} + \text{Cl – Cl} \rightarrow \cdot \text{CH}_2\text{Cl} + \text{HCl}$ $\text{CH}_3\text{Cl} + \text{Cl} \rightarrow \cdot \text{CH}_2\text{Cl}_2 + \text{Cl} \cdot$ $\text{Step 3: Termination:}$ $\text{The formation of ethane is a result of the termination of chain reactions}$ $\text{taking place as a result of the consumption of}$ $\text{reactants as:}$ $\text{Cl} \cdot + \text{Cl} \cdot \rightarrow \text{Cl – Cl}$ $\text{H}_3\text{C} \cdot + \cdot \text{CH}_3 \rightarrow \text{H}_3\text{C – CH}_3$ $\text{(Ethane)}$ $\text{Hence, by this process, ethane is obtained as a by-product of the}$ $\text{chlorination of methane}$