Propyne on cyclic polymerisation gives

When ethyl bromide reacts with sodium acetylide,the main product is:

Which of the following order of reagents is chosen to prepare $1, 3-$butadiene from $C_2H_2$?

Which of the following reactions gives $H_2C=C=C=CH_2$?

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

An unknown compound $X$ is an unsaturated hydrocarbon. It reacts with $HgSO_4$ and $H_2SO_4$ to give compound $(B)$. Compound $(B)$ on oxidation gives compound $(C)$. Compound $(C)$ on reaction with $NaOH$ and soda lime gives methane. Identify $A$ (which is $X$),$B$,and $C$ by providing the chemical reactions.