The reaction of $1,1,2,2$-tetrabromoethane with zinc dust produces .............

In the reaction sequence $CaC_2$ $\xrightarrow{H_2O} A$ $\xrightarrow[dil. H_2SO_4]{Hg^{+2}} B$ $\xrightarrow{Ni} H_2 C$,the product $C$ is:

Which one of the following carbonyl compounds cannot be prepared by addition of water on an alkyne in the presence of $HgSO_4$ and $H_2SO_4$?

What is the product formed when $CH_3CH_2CHCl_2$ is treated with $NaNH_2$?

$But-1-yne$ and $But-2-yne$ can be distinguished by

Which reactant is used to prepare trans alkene from alkyne?