Which product is obtained from the reaction of calcium carbide with water?

$CH_3-CH_2-C \equiv CH \xrightarrow{R, H_2O} \text{Butanone}$. $R$ is:

When $1,2-$dibromopropane is treated with $X$ moles of $NaNH_2$,the resulting compound reacts with ethyl bromide to form pentyne. What is the value of $X$?

Acetylene is obtained by the electrolysis of

Acetylene reacts with dilute $H_2SO_4$ in the presence of $HgSO_4$ to produce .......

Propyne on hydration in the presence of $H_2SO_4$ and $HgSO_4$ gives: