Question

Which among the following is haloalkyne?

• A. Halogen atom is bonded to $\mathrm{sp^2}$ hybridized carbon atom of aromatic a ring.
• B. Halogen atom is bonded to $\mathrm{sp^3}$ hybridized carbon atom next to $\mathrm{C = C}$ double bond in aliphatic chain.
• C. Halogen atom is bonded to $\mathrm{sp}$ hybridized carbon atom in aliphatic chain.
• D. Halogen atom is bonded to $\mathrm{sp^2}$ hybridized carbon atom in aliphatic chain.

Hint:

Associate hybridization states directly with bond types for carbon: $\mathrm{sp^3} \rightarrow$ single bonds (alkane), $\mathrm{sp^2} \rightarrow$ double bond (alkene), and $\mathrm{sp} \rightarrow$ triple bond (alkyne).

Answer 1

The Correct Option is C

Step 1: Break down the word.
Haloalkyne means a halogen bonded to an alkyne carbon, and alkyne carbons carry a $\mathrm{C \equiv C}$ triple bond.
Step 2: Fix the hybridisation.
A carbon in a triple bond is $sp$ hybridised, so a true haloalkyne has its halogen on an $sp$ carbon in an aliphatic chain.
Step 3: Test option A.
Halogen on an $sp^2$ aromatic carbon describes a haloarene, not a haloalkyne.
Step 4: Test options B and D.
Halogen on an $sp^3$ carbon next to $\mathrm{C=C}$ is an allylic halide; halogen on an $sp^2$ aliphatic carbon is a vinylic halide. Neither matches.
Step 5: Test option C.
Halogen on an $sp$ carbon of an aliphatic chain matches the alkynyl carbon exactly, so this is the haloalkyne.
Step 6: Conclude.
The correct description is halogen on an $sp$ hybridised carbon in an aliphatic chain, option (C).
\[ \boxed{\text{Halogen on } sp \text{ carbon (aliphatic)}} \]