The reaction $R-C \equiv C-R \xrightarrow{H_2 / \text{Lindlar's catalyst}}$ gives the major product as ..............

Which of the following is(are) example$(s)$ of nucleophilic addition reaction in the case of acetylene?

What is the product formed when $4$-octyne reacts with $H_2$ in the presence of $Pd/CaCO_3$?

To convert $1$-butyne to $1-D$-butanal,one would carry out the following steps :
$(I)$ Sodium amide,then $D_2O$
$(II)$ Disiamylborane,then hydrogen peroxide/sodium hydroxide
$(III)$ The transformation can not be carried out with the indicated reagents.

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

When acetylene reacts with arsenic trichloride in the presence of anhydrous aluminium chloride,it produces