Identify a reagent from the following list which can easily distinguish between 1 -butyne and 2-butyne.

Question

Identify a reagent from the following list which can easily distinguish between 1 -butyne and 2-butyne. (A) bromine, CCl4 (B) H2, Lindlar catalyst (C) dilute H2 SO4, Hg SO4 (D) ammoniacal CuCl2 solution

Tardigrade Admin · Accepted Answer

Ammoniacal CuCl2 forms red precipitate with terminal alkynes, can be used to distinguish terminal alkynes from internal alkynes: CH3 - CH2- C ≡ C- H + CuCl2 xrightarrowNH3 (aq) CH3 - CH2- C ≡ C-Cu+ downarrow

Q. Identify a reagent from the following list which can easily distinguish between $1$ -butyne and $2$ -butyne.

bromine, $CC l_{4}$

$H_{2},$ Lindlar catalyst

dilute $H_{2} S O_{4}, H g S O_{4}$

ammoniacal $C u C l_{2}$ solution

Ammoniacal $C u C l_{2}$ forms red precipitate with terminal alkynes, can be used to distinguish terminal alkynes from internal alkynes:
$C H_{3} - C H_{2} - C \equiv C - H + C u C l_{2} N H_{3} (a q)$
$C H_{3} - C H_{2} - C \equiv C^{-} C u^{+} ↓$

Q. Identify a reagent from the following list which can easily distinguish between 1 -butyne and 2-butyne.

bromine, CCl4​

H2​, Lindlar catalyst

dilute H2​SO4​,HgSO4​

ammoniacal CuCl2​ solution