Which reagent will you use for the following reaction ?
`CH_(3)CH_(2)CH_(2)CH_(3)toCH_(3)CH_(2)CH_(2)CH_(2)Cl+CH_(3)CH_(2)CHClCH_(3)`

Options

A. `Cl_2//UV` light
B. `NaCl+H_2SO_4`
C. `Cl_2` gas in dark
D. `Cl_2` gas in the presence of iron in dark

Explanation

To determine the reagent needed for the reaction converting butane (C₄H₁₀) to a mixture of 1-chlorobutane and 2-chlorobutane, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants and Products**:
- Reactant: Butane (C₄H₁₀) - CH₃CH₂CH₂CH₃
- Products: 1-Chlorobutane (CH₃CH₂CH₂CH₂Cl) and 2-Chlorobutane (CH₃CH₂CHClCH₃)

2. **Understand the Reaction Type**:
- The reaction involves the substitution of hydrogen atoms in butane with chlorine atoms, which indicates a halogenation reaction.

3. **Recognize the Mechanism**:
- The halogenation of alkanes typically proceeds via a free radical mechanism. This involves the formation of radicals that react with chlorine.

4. **Select the Reagent**:
- The appropriate reagent for this reaction is chlorine gas (Cl₂). However, since the reaction requires the formation of radicals, it must be done in the presence of ultraviolet (UV) light.

5. **Write the Reaction**:
- The reaction can be summarized as follows:
\[ \text{C₄H₁₀} + \text{Cl₂} \xrightarrow{\text{UV light}} \text{C₄H₉Cl} + \text{C₄H₉Cl} \]
- This indicates that butane reacts with chlorine to form both 1-chlorobutane and 2-chlorobutane.

### Final Answer:
The reagent used for the conversion of butane to 1-chlorobutane and 2-chlorobutane is **Cl₂ (chlorine gas) in the presence of UV light**.

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