Identify the $X$ in the reaction.
$R-NH_2 + HNO_2 \underset{273-278 \ K}{}$ ${\xrightarrow{NaNO_2 + HCl}} X$ $\xrightarrow{H_2O} R-OH + N_2 + HCl$

Identify the major product formed in the following sequence of reactions:
Aniline $\xrightarrow{Br_2/H_2O}$ $2,4,6-$Tribromoaniline $\xrightarrow{NaNO_2/HCl}$ $2,4,6-$Tribromobenzenediazonium chloride $\xrightarrow{H_3PO_2/H_2O}$ Product.

$X \ g$ of ethylamine is subjected to reaction with $NaNO_2 / HCl$ followed by water; evolved dinitrogen gas which occupied $2.24 \ L$ volume at $STP$. $X$ is . . . . . . $\times 10^{-1} \ g$.

The correct order of basicity of the various nitrogen atoms in $LSD$ is:

Write structures of different isomers corresponding to the molecular formula $C_{3}H_{9}N$. Write $IUPAC$ names of the isomers which will liberate nitrogen gas on treatment with nitrous acid.

The major product $B$ in the following reaction sequence is:
$CH_3-CH_2-CH(CH_3)-CONH_2$ $\xrightarrow{Br_2/KOH, \Delta} (A)$ $\xrightarrow{(1) CH_3I (excess), (2) AgOH/\Delta} (B)$