Primary and secondary amines are distinguished by
$(i)$ Hinsberg test
$(ii)$ Carbyl amine test
$(iii)$ Hofmann mustard oil test
$(iv)$ $HNO_2$ test

The product of this Hoffmann bromamide reaction is:

Consider the following sequence of reactions. Assuming that the reaction proceeds to completion, then $137 \ mg$ of $4-$nitrotoluene will produce . . . . . . $mg$ of $B$. (Given molar mass in $g \ mol^{-1}: H = 1, C = 12, N = 14, O = 16, Br = 80$)

Three isomers $A$,$B$,and $C$ (molecular formula $C_8H_{11}N$) give the following results:
$A$ and $C$ $\xrightarrow{\text{Diazotization}}$ $P + Q$ $\xrightarrow[(ii) \text{ oxidation } (KMnO_4 + H^{+})]{(i) \text{ Hydrolysis}}$ $R$ (product of $A$) and $S$ (product of $C$)
Identify $A$,$B$,and $C$ from the given options.

In which of the following reactions is a tertiary amine formed?

The correct sequence of reagents for the following transformation is: