Question

Ethyne can be prepared from

• A. Calcium carbide
• B. Ethylene dibromide
• C. Both (a) and (b)
• D. None of the above

Answer 1

The correct option is C Both (a) and (b)

$Ca{C}_2+2H_{2}O\to H-C\equiv C-H+Ca(OH{)}_2$
This is the industrial method of preparation of ethyne.

Vicinal dihalides on treatment with alcoholic KOH undergo dehydrohalogenation. One molecule of HX is eliminated to form alkenyl halide which on treatment with sodamide gives alkyne.

So, the correct answer will be option (c).