General Description
A yellow crystalline solid. Easily ignited by friction. Forms sulfur dioxide and phosphorus pentaoxide during combustion. Reacts with water to form phosphoric acid, a corrosive material. Used to make matches and in the manufacture of other chemicals.
Air & Water Reactions
Highly flammable.Slowly decomposed by water to form phosphoric acid and toxic hydrogen sulfide gas (H2S). May ignite on contact with water or moist air.
Reactivity Profile
PHOSPHORUS SESQUISULFIDE is a reducing agent.
Health Hazard
Highly toxic: contact with water produces toxic gas, may be fatal if inhaled. Inhalation or contact with vapors, substance or decomposition products may cause severe injury or death. May produce corrosive solutions on contact with water. Fire will produce irritating, corrosive and/or toxic gases. Runoff from fire control may cause pollution.
Fire Hazard
Produce flammable and toxic gases on contact with water. May ignite on contact with water or moist air. Some react vigorously or explosively on contact with water. May be ignited by heat, sparks or flames. May re-ignite after fire is extinguished. Some are transported in highly flammable liquids. Containers may explode when heated. Runoff may create fire or explosion hazard.
Chemical Properties
Yellowish-green crystals; melts at 172°C (341°F); boils at 407–408°C (764–766°F);density 2.03 at 20°C (68 °F); soluble in carbon disulfide, benzene, and toluene, reacts with water..
Flammability and Explosibility
Flammable
Synthesis
Phosphorus trisulfide can be synthesized either by Stock's method
(I), which involves fusing red P and S and carefully purifying the
crude product by recrystallization from CS3, followed by a second
recrystallization from benzene, or according to German patent
309,618 (F. C. Frary), which uses white P in a high-melting
inert solvent (II).
4 P + 3 S = P4S3
Purification Methods
Extract P4S3with CS2, filter it and evaporate it to dryness. Alternatively place it in H2O, and pass steam through it for an hour. The H2O is then removed, the solid is dried, and recrystallised from CS2 [Rogers & Gross J Am Chem Soc 74 5294 1952].
Waste Disposal
An alkaline solution is treated with laundry bleach, allowed to stand overnight, neutralized, and washed down the drain with plenty of water.
