Question

When treated with ammoniacal cuprous chloride, which one among the following forms copper derivative

• A. C₂H₆
• B. C₂H₄
• C. C₂H₂
• D. C₆H₆

Answer 1

The correct option is C

C₂H₂

Acetylene on reaction with ammonical cuprous chloride solution gives reddish brown or dark red prescipitate of copper acetylide.

$H-C\equiv C-H+\underset{2N{H}_{4}OH}{\overset{C{u}_{2}C{l}_2}{\to }}Cu-C\equiv C-Cu\downarrow$
$Copperacetylide$
In the above reaction $2N{H}_{3}Cl+2H_{2}O$ are also formed in the products' side.

$2R-C\equiv C-H\underset{2N{H}_{4}OH}{\overset{C{u}_{2}C{l}_2}{\to }}2R-C\equiv C-Cu+2N{H}_{4}Cl+2H_{2}O$

$R-C\equiv C-R+\underset{2N{H}_{4}OH}{\overset{C{u}_{2}C{l}_2}{\to }}$ No reaction