A basic volatile nitrogen compound gave a foul smelling gas when treated with chloroform and alcoholic KOH. A 0.295 g sample of the substance dissolved in aq. HC1 and treated with NaNO2 solution at 0°C, liberated a colourless, odourless gas whose volume corresponds to 112 mL at STP. After evolution of the gas was complete, the aqueous solution was distilled to give an organic liquid which did not contain nitrogen and which on warming with alkali and iodine gave a yellow precipitate. Identify the original substance assuming that it contains one N-atom per molecule.

Question

A basic volatile nitrogen compound gave a foul smelling gas when treated with chloroform and alcoholic KOH. A 0.295 g sample of the substance dissolved in aq. HC1 and treated with NaNO2 solution at 0°C, liberated a colourless, odourless gas whose volume corresponds to 112 mL at STP. After evolution of the gas was complete, the aqueous solution was distilled to give an organic liquid which did not contain nitrogen and which on warming with alkali and iodine gave a yellow precipitate. Identify the original substance assuming that it contains one N-atom per molecule. (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

Starting compound is a primary amine. R-NH2+CHCI3 +KCI arrow foul smellR-NC Also, R-NH2+HNO2 arrow R-OH+N2 Moles of N2 =(112/22500)=5 × -3 ∵ One mole of N2 2 is obtained from 1.0 mole of R- NH2, mole of R-NH2=5 × 10-3 ⇒ 5 × 10-3 mol R-NH2 weight=0.295 g 1 mole of R-NH2 will weigh =(0.295/5 × 10-3)=59 g In R-NH2 -NH2has molar mass =16 ⇒ R-has molar mass=43 Also, the alcohol R-OH gives iodoform test; it must has the following skeleton :