The chlorination of methane is an example of

Options

A. elimination reaction
B. substitution reaction
C. addition reaction
D. oxidation reaction

Answer

To determine the type of reaction that occurs during the chlorination of methane, we can break down the process step by step.

### Step-by-Step Solution:

1. **Identify the Reactants**: The reaction involves methane (CH₄) and chlorine (Cl₂).

2. **Understand the Reaction Process**: The chlorination of methane occurs in the presence of light or heat, which initiates the reaction.

3. **Initiation Step**: In the presence of light, chlorine molecules undergo homolytic cleavage, resulting in the formation of two chlorine radicals (Cl•). This step is crucial as it generates the reactive species needed for the reaction.

\[ \text{Cl}_2 \xrightarrow{\text{light}} 2 \text{Cl}• \]

4. **Propagation Steps**:
- The chlorine radical (Cl•) reacts with methane (CH₄), substituting one hydrogen atom to form methyl radical (CH₃•) and hydrogen chloride (HCl).

\[ \text{Cl}• + \text{CH}_4 \rightarrow \text{CH}_3• + \text{HCl} \]

- The methyl radical (CH₃•) then reacts with another chlorine radical (Cl•) to form chloromethane (CH₃Cl) and regenerate the chlorine radical.

\[ \text{CH}_3• + \text{Cl}• \rightarrow \text{CH}_3\text{Cl} + \text{Cl}• \]

5. **Termination Step**: The reaction can terminate when two radicals combine. This can happen in several ways:
- Two chlorine radicals can combine to form Cl₂.
- Two methyl radicals can combine to form ethane (C₂H₆).
- A methyl radical and a chlorine radical can combine to form chloromethane (CH₃Cl).

\[ \text{Cl}• + \text{Cl}• \rightarrow \text{Cl}_2 \]
\[ \text{CH}_3• + \text{CH}_3• \rightarrow \text{C}_2\text{H}_6 \]
\[ \text{CH}_3• + \text{Cl}• \rightarrow \text{CH}_3\text{Cl} \]

6. **Conclusion**: Since one hydrogen atom in methane is replaced by a chlorine atom, this process is classified as a **substitution reaction**.

### Final Answer:
The chlorination of methane is an example of a **substitution reaction**.

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