Concept Explanation: Identifying Compound X

The given reaction shows a compound X reacting with chlorine in the presence of sunlight to produce chloromethane and hydrogen chloride. This is a characteristic substitution reaction of alkanes.

Step 1: Recognize the Reaction Type

The reaction: X + Cl₂ → CH₃Cl + HCl indicates a free radical substitution reaction that occurs with alkanes under UV light/sunlight.

Step 2: Analyze the Products

The product is chloromethane (CH₃Cl), which suggests that the original compound X must be methane (CH₄). The reaction follows this equation:

$CH 4 + Cl 2 \overset{sunlight}{\to} CH 3 Cl + HCl$

Step 3: Eliminate Other Options

Other options would produce different products:

Ethane (H₃C-CH₃) would give chloroethane
Cycloalkane structures would give different substitution patterns

Final Answer

Therefore, compound X is CH₄ (methane).

Related Topics

Alkane halogenation reactions
Free radical substitution mechanism
Photochemical reactions in organic chemistry

Important Formulae

General reaction for alkane chlorination:

$R - H + Cl 2 \overset{hv}{\to} R - Cl + HCl$

Theory

Methane undergoes free radical substitution with chlorine in the presence of sunlight through a chain reaction mechanism involving initiation, propagation, and termination steps. The reaction is highly specific for alkanes and follows Markovnikov's rule for more complex alkanes.