Question

Which reagent will be used for the following reaction? 
CH₃CH₂CH₂CH₃ → 

Hint:

Free radical substitution in alkanes requires halogen (\( Cl_2 \) or \( Br_2 \)) and UV light. It proceeds via initiation, propagation, and termination steps.

Answer 1

Step 1: Identifying the Reaction Type 
- The given reaction involves a simple alkane (butane, \( C_4H_{10} \)).
- Alkanes undergo free radical substitution reactions in the presence of halogens and UV light. 
Step 2: Reaction Mechanism 
The reaction follows a free radical chain mechanism consisting of three steps: 1. Initiation Step: Formation of chlorine radicals under UV light \[ Cl_2 \xrightarrow{UV} 2Cl\cdot \] 2. Propagation Step: Substitution of a hydrogen atom in butane \[ C_4H_{10} + Cl\cdot \rightarrow C_4H_9\cdot + HCl \] \[ C_4H_9\cdot + Cl_2 \rightarrow C_4H_9Cl + Cl\cdot \] 3. Termination Step: Combination of free radicals to stop the chain reaction \[ Cl\cdot + Cl\cdot \rightarrow Cl_2 \] 
Step 3: Conclusion 
- The reagent required for this reaction is chlorine (\( Cl_2 \)) and ultraviolet (UV) light.
- The UV light helps break the Cl-Cl bond, generating chlorine radicals that drive the reaction.