The compound belonging to the homologous series of ethyne is .........

In which of the following cases is the bond length between carbon and nitrogen minimum?

Chloroform,on warming with $Ag$ powder,gives:

Acetylene can be obtained by the reaction:

In the reaction,$H_3C-C\equiv C-H$ $\xrightarrow[2. x]{1. NaNH_2, \Delta}$ $\xrightarrow{3. y} H_3C-CH=CH-CH_3$ (trans form),$x$ and $y$,respectively are

In the reaction
$HC \equiv CH \xrightarrow[(ii) CH_3CH_2Br]{(i) NaNH_2 / liq. NH_3} X$
$\xrightarrow[(ii) CH_3CH_2Br]{(i) NaNH_2 / liq. NH_3} Y$
$X$ and $Y$ are