Preparation

Nitrogen trichloride is prepared by passing chlorine gas into slightly acid solution of ammonium chloride. The product is continuously extracted with carbon tetrachloride: NH4Cl + 3Cl2 → NCl3 + 4HCl Hypochlorous acid, HOCl, also may be used instead of chlorine in such preparation. Nitrogen trichloride can be prepared by the action of anhydrous chlorine with anhydrous ammonia: 3Cl2 + NH3 → NCl3 + 3HCl Nitrogen trichloride is made commercially by electrolyzing an acidified solution of ammonium chloride.

Hazard

Explodes when heated to approximately 200F (93C) or when exposed to direct sunlight. Toxic by ingestion and inhalation, strong irritant.

Safety Profile

Moderately toxic by inhalation. An irritant to the eyes, skin, mucous membranes, and a systemic central nervous system irritant. An explosive sensitive to impact, light, and ultrasound. The solid explodes on melting. The liquid explodes above 60°C. Concentrated solutions are also explosive. Explosive decomposition is initiated by contact with: concentrated ammonia, arsenic, dinitrogen tetraoxide, hydrogen sulfide, hydrogen trisulfide, nitrogen oxide, organic matter, ozone, phosphine, phosphorus, potassium cyanide, potassium hydroxide solutions, selenium, hydrogen chloride, hydrogen fluoride, hydrogen bromide, hydrogen iodide. mxtures with chlorine + hydrogen are potentially explosive. Upon decomposition it emits toxic fumes of Cl- and NOx. See also CHLORIDES.

Physical properties

Yellow, oily, heavy liquid; pungent odor; density 1.653 g/mL; freezes to rhombohedral crystalline solid below -40°C; evaporates in air rapidly; vaporpressure 150 torr at 20°C; explodes when heated at 93°C; highly unstable, decomposes explosively in light; insoluble in water, decomposes slowly in cold water after several hours; decomposes in hot water; soluble in benzene, chloroform, carbon tetrachloride, carbon disulfide and phosphorus trichloride.