Question

A translucent white waxy solid (a) on heating in an inert atmosphere is converted to its allotropic form (b).Allotrope (a) on reaction with very dilute aqueous koh liberates a highly poisonous gas (c) having rotten fishsmell. With excess of chlorine forms (d) which hydrolyses to compound (e). Identify compounds (a) to (e). 5

Answer 1

‘A’ is white phosphorus.When white phosphours is heated in an inert atmosphere at 573K, it changes to red phosphorus ‘B’.‘A’ on heating with KOH liberates phosphine ‘C’ which is poisonous gas with rotten fish smell. White phosphorus burns with excess of Cl2 to form phosphorus pentachloride ‘D’. Hydrolysis of ‘D’ gives phosphoric acid ‘E’.