$A$ colourless organic compound gives brisk effervescence with a mixture of sodium nitrite and dil. $HCl$. It could be

The carbylamine test is used to detect the presence of a primary amino group in an organic compound. Which of the following compounds is formed when this test is performed with aniline?

Which among the following reagents is used to distinguish primary $(1^{\circ})$,secondary $(2^{\circ})$,and tertiary $(3^{\circ})$ amines according to their solubility in an alkaline medium?

Which one of the following compounds gives a blue color when treated with nitrous acid $(HNO_2)$?

Which of the following reacts with Hinsberg reagent to give a product which is soluble in alkali?

Carbylamine test is performed by heating alcoholic $KOH$ with: