Question

Identify the Alkane (molecular formula \( C_8H_{18} \)) which yields only a single monochloride on Chlorination in the presence of sunlight.

• A. 2,2,4-Trimethylpentane
• B. 2,4-Dimethylhexane
• C. 2,2,3,3-Tetramethylbutane
• D. 3,4-Dimethylhexane

Hint:

For single monochlorination product, always check molecular symmetryIf all hydrogens are equivalent, only one product forms.

Answer 1

The Correct Option is C

Step 1: Understand the concept of monochlorination.
Monochlorination of an alkane involves substitution of one hydrogen atom by chlorine. If all hydrogen atoms in a molecule are equivalent, only one monochlorinated product will form.

Step 2: Analyze symmetry requirement.
For a single monochloride to form, the alkane must be highly symmetrical so that all hydrogen atoms are chemically equivalent.

Step 3: Evaluate option (C).
In \( 2,2,3,3\text{-Tetramethylbutane} \), the structure is highly symmetrical. All hydrogen atoms are attached to equivalent methyl groups.
Thus, substitution at any hydrogen position gives the same product.

Step 4: Check other options.
(A), (B), and (D) have different types of hydrogen atoms (primary, secondary, tertiary), so they give multiple monochlorinated products.

Step 5: Conclusion.
Only \( 2,2,3,3\text{-Tetramethylbutane} \) gives a single monochloride due to complete symmetry.
Therefore:
\[ \boxed{2,2,3,3\text{-Tetramethylbutane}} \]