$R-CH_2-CCl_2-R \xrightarrow{\text{Reagent}} R-C \equiv C-R$
The reagent is

$H_3C-C \equiv CH$ $\xrightarrow{NaNH_2} A$ $\xrightarrow{CH_3CH_2Br} B$ $\xrightarrow{H_2/Pd, BaSO_4} C$
Identify product $(C)$?

When acetylene is passed through dilute sulfuric acid containing mercuric sulfate,determine the number of $\pi$-bonds in the product formed.

Which of the following compounds is capable of reacting with ammoniacal $AgNO_3$ solution?

What is the product when $2-$butyne is treated with liquid $NH_3$ in the presence of lithium?

To carry out the above conversion,$(A)$ and $(B)$ respectively are: