Ethyne can be obtained from.......

Explain the polymerization of alkynes. Or,give the types of polymerization of alkynes and provide a note on each.

Identify the structure of the final product $(D)$ in the following sequence of reactions:
$Ph-CO-CH_3$ $\xrightarrow{PCl_5, \Delta} A$ $\xrightarrow{3 \text{ eq. } NaNH_2/NH_3} B$ $\xrightarrow{\text{Acidify}} C$ $\xrightarrow{1. B_2H_6, 2. H_2O_2/OH^-} D$
Total number of $sp^2$ hybridised carbon atoms in product $D$ is:

Which reaction converts $2$-hexyne into $trans$-$2$-hexene?

Which of the following has the shortest $C - C$ bond length?

$A$ $\xrightarrow[1\% \ HgSO_4]{20\% \ H_2SO_4} B$ $\xrightarrow{I_2 + NaOH} C + C_6H_5COONa$. The reactant $A$ is