Phosphorus Flamethrower: A Demonstration Using Red and White Allotropes of Phosphorus

A demonstration was created to display the unique behavior of a familiar element, phosphorus, and to make chemistry more accessible to the introductory student. The common allotropes of phosphorus and their reactivity are discussed. In this demonstration, the white allotrope of phosphorus is synthesized from the red phosphorus obtained from a matchbook. White phosphorus is exposed to oxygen in the air, and an eye-catching flame is produced. This simple, effective, and dramatic demonstration shows the conversion between red and white allotropes of phosphorus, its reaction with oxygen to form phosphorus oxides, and hydrolysis to form phosphoric acid. Care has been taken to minimize the hazards of burning white phosphorus and to identify proper methods of disposal.