The reaction between `CH_4` and chlorine in presence of sunlight is an example of-

Options

A. Substitution reaction
B. Combination reaction
C. Addition reaction
D. Decomposition reaction

Explanation

To determine the type of reaction that occurs when methane (CH₄) reacts with chlorine (Cl₂) in the presence of sunlight, we can analyze the process step by step.

### Step-by-Step Solution:

1. **Identify the Reactants and Conditions**:
- The reactants are methane (CH₄) and chlorine (Cl₂).
- The reaction occurs in the presence of sunlight.

2. **Understand the Reaction Mechanism**:
- In the presence of sunlight, the chlorine molecule (Cl₂) undergoes homolytic fission, breaking into two chlorine radicals (Cl·).
- This process generates free radicals, which are highly reactive species.

3. **Substitution Process**:
- One of the chlorine radicals (Cl·) reacts with methane (CH₄).
- The chlorine radical replaces one hydrogen atom in methane, resulting in the formation of chloromethane (CH₃Cl) and a hydrogen radical (H·).
- The hydrogen radical then reacts with another chlorine radical to form hydrogen chloride (HCl).

4. **Identify the Type of Reaction**:
- The key feature of this reaction is that one atom (hydrogen) is replaced by another atom (chlorine) without changing the overall number of reactants and products.
- This is characteristic of a substitution reaction, where an atom or group of atoms in a molecule is replaced by another atom or group of atoms.

5. **Conclusion**:
- Therefore, the reaction between CH₄ and chlorine in the presence of sunlight is an example of a **substitution reaction**.