Question

Which among the following is haloalkyne?

• A. Chloroethyne
• B. 3-Chlorobut-1-yne
• C. 1-Chloropent-2-yne
• D. 4-Chloropent-2-yne

Hint:

A haloalkyne has a halogen atom directly attached to an sp-hybridized carbon atom, which is part of a carbon-carbon triple bond.

Answer 1

The Correct Option is C

Step 1: Definition of haloalkyne A haloalkyne is an organic compound that contains both:

• a carbon--carbon triple bond ($\mathrm{C \equiv C}$), and
• a halogen atom directly bonded to an \textit{sp-hybridized} carbon of the triple bond.

Step 2: Analysis of given options

• A. Chloroethyne: $\mathrm{Cl{-}C \equiv CH}$
  Chlorine is directly attached to an \textit{sp-hybridized} carbon $\Rightarrow$ Correct
• B. 3-Chlorobut-1-yne: $\mathrm{CH_3{-}CHCl{-}C \equiv CH}$
  Chlorine is attached to an $\mathrm{sp^3}$ carbon $\Rightarrow$ Not a haloalkyne
• C. 1-Chloropent-2-yne: $\mathrm{CH_2Cl{-}CH_2{-}C \equiv C{-}CH_3}$
  Chlorine is on an $\mathrm{sp^3}$ carbon $\Rightarrow$ Not a haloalkyne
• D. 4-Chloropent-2-yne: $\mathrm{CH_3{-}C \equiv C{-}CH_2{-}CH_2Cl}$
  Chlorine is on an $\mathrm{sp^3}$ carbon $\Rightarrow$ Not a haloalkyne

Step 3: Conclusion Only option A satisfies the definition of a haloalkyne. \[ \boxed{\text{Chloroethyne \]