Substance profile
Phosphorus pentachloride
Phosphorus pentachloride is a white to pale yellow crystalline mass with a pungent, unpleasant odor.
01 · Identification
What Phosphorus pentachloride is
Phosphorus pentachloride is a white to pale yellow crystalline mass with a pungent, unpleasant odor. Its molecular formula is Cl5P and its molecular weight is 208.2 g/mol. It boils at 160 °C, melts at 161 °C.
Under the GHS it carries the signal word Danger. It is classed as corrosives.
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
| Code | Hazard statement |
|---|---|
| H330 | Fatal if inhaled. |
| H302 | Harmful if swallowed. |
| H373 | May cause damage to organs <or state all organs affected, if known> through prolonged or repeated exposure <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>. |
| H314 | Causes severe skin burns and eye damage. |
Supplemental EU statements: EUH014, EUH029
Precautionary statements: P260, P270, P271, P280, P301, P304, P310, P312, P314, P330, P331
03 · Physical and chemical properties
Phosphorus pentachloride properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Boiling point | 160 °C (320 °F) | at 760 mmHg | CAMEO |
| 159 °C (318.2 °F) | sublimes, sublimes | HSDB | |
| Sublimes | sublimes | NIOSH | |
| Melting point | 160.5 °C (320.9 °F) | freezing point | HSDB |
| 148 °C (298.4 °F) | sublimes, under pressure | HSDB | |
| 162.22 °C (324 °F) | sublimes | NIOSH | |
| Density | 3.6 g/cm³ | NIOSH | |
| 2.114 g/cm³ | at 25.15 °C | HSDB | |
| Solubility | Hygroscopic | HSDB | |
| Sol in carbon disulfide, carbon tetrachloride | HSDB | ||
| Reacts with water; soluble in carbon disulfide, carbon tetrachloride | HSDB | ||
| Vapor pressure | 0.012 mmHg | at 20 °C | HSDB |
| 1 mmHg | at 55.5 °C | HSDB | |
| Lower explosive limit (LEL) | Noncombustible Solid | NIOSH | |
| Vapor density | 7.2 (air = 1) | HSDB | |
| Critical temperature and pressure | 372 °C (701.6 °F) | HSDB | |
| Corrosivity | Corrosive | HSDB |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Fire and explosion
Fire and explosion behaviour of Phosphorus pentachloride
These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.
Fire and explosion
The residue from interaction of the chloride and anilide in benzene after removal of solvent and phosphoryl chloride under vacuum exploded violently on admission of air.
Source: HSDB
A solution of phosphorus pentachloride in nitrobenzene is stable at 110 °C but begins to decompose with acceralating violence above 120 °C, with evolution of nitrous fumes.
Source: HSDB
05 · Handling and storage
Storing and handling Phosphorus pentachloride
Storage conditions
Store in a glass bottle with a ground glass stopper and keep the bottle tightly closed. Protect against physical damage.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Hydrolyzed by water to form phosphoric acid & hydrogen chloride.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
PHOSPHORUS PENTACHLORIDE is a lightly yellow, fuming crystalline material, highly caustic, corrosive and toxic. Flammable by chemical reaction. Violent exothermic reaction with water or steam. When heated to decomposition it emits highly toxic fumes of chlorides and oxides of phosphorus. Explosive reaction with alkaline metals (sodium, potassium), urea. Ignites on contact with fluorine. Violent reaction with aluminum, chlorine trioxide, hydroxylamine, magnesium oxide, nitrobenzene, phosphorus(III) oxide, potassium. Carbamates form explosive products [Bretherick, 5th ed., 1995, p. 1360]. Reaction with the mixture of chlorine and chlorine dioxide causes explosion [Mellor, 1941, vol. 2, p. 281; 1940, vol. 8, p. 1013].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Phosphorus pentachloride in the storage compatibility matrix →