The reagent needed for converting $Ph-C \equiv C-Ph$ to trans-stilbene is:

Give the method of preparation of ethyne (acetylene) from vicinal dihalides.

Write the following reactions:
$1$. Complete combustion of ethyne in the presence of air.
$2$. Reaction of propyne with alkaline $KMnO_4$.

The reaction of acetylene with acetic acid in the presence of $Hg^{2+}$ at room temperature yields ....

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.

Which one of the following compounds will react with methyl magnesium iodide?