Phosphorus oxychloride (POCl3) is a chemical compound used in various industrial processes. It reacts with water to form phosphoric acid and hydrochloric acid.
| IUPAC Name | Phosphorus oxychloride |
| Molecular Formula | POCl3 |
| CAS Number | 10025-87-3 |
| Synonyms | Phosphoryl chloride, Phosphoryl trichloride, Phosphoric trichloride |
| InChI | InChI=1S/Cl3OP/c1-4(2)3 |
Phosphorus Oxychloride Properties
Phosphorus Oxychloride Formula
The chemical formula of phosphoryl chloride is POCl3. It consists of one phosphorus atom (P), symbolized by P, and three chlorine atoms (Cl), symbolized by Cl. The formula indicates the ratio of each element present in the compound.
Phosphorus Oxychloride Molar Mass
The molar mass of phosphoryl chloride can be calculated by summing the atomic masses of its constituent elements. Phosphorus has a molar mass of 30.97 g/mol, while chlorine has a molar mass of 35.45 g/mol. Multiplying the molar mass of chlorine by 3 and adding the molar mass of phosphorus gives a total molar mass of approximately 153.33 g/mol for phosphoryl chloride.
Phosphorus Oxychloride Boiling Point
Phosphoryl chloride has a boiling point of around 105.5°C. This temperature represents the point at which the liquid compound changes to a gaseous state under standard atmospheric pressure. The boiling point is an important characteristic that affects the handling and application of phosphoryl chloride.
Phosphorus Oxychloride Melting Point
The melting point of phosphoryl chloride is approximately -112.5°C. It signifies the temperature at which the solid compound transitions into a liquid state. The melting point is a critical parameter for storage and transportation considerations.
Phosphorus Oxychloride Density g/mL
The density of phosphoryl chloride is about 1.65 g/mL. Density refers to the amount of mass per unit volume of a substance. A higher density suggests a greater concentration of particles in a given volume.
Phosphorus Oxychloride Molecular Weight
The molecular weight of phosphoryl chloride is calculated by summing the atomic masses of its constituent elements. The molecular weight of phosphorus is approximately 30.97 g/mol, while chlorine has a molecular weight of 35.45 g/mol. Adding the weighted masses gives an approximate molecular weight of 153.33 g/mol for phosphoryl chloride.
Phosphorus Oxychloride Structure
Phosphoryl chloride has a molecular structure where one phosphorus atom is bonded to three chlorine atoms and one oxygen atom. The chlorine atoms are arranged symmetrically around the central phosphorus atom, with the oxygen atom also bonded to the phosphorus atom. This arrangement forms a tetrahedral geometry.
Phosphorus Oxychloride Solubility
Phosphoryl chloride is sparingly soluble in water but dissolves readily in organic solvents such as benzene, carbon tetrachloride, and chloroform. Its solubility behavior is attributed to the polar nature of the molecule and the presence of electronegative atoms like oxygen and chlorine.
| Appearance | Colorless liquid |
| Specific Gravity | 1.645 g/mL |
| Color | Colorless |
| Odor | Pungent |
| Molar Mass | 153.33 g/mol |
| Density | 1.645 g/mL |
| Melting Point | -112.5°C |
| Boiling Point | 105.5°C |
| Flash Point | Not applicable |
| Water Solubility | Reacts vigorously |
| Solubility | Soluble in organic solvents such as benzene, carbon tetrachloride, and chloroform |
| Vapor Pressure | 11 mmHg at 20°C |
| Vapor Density | 5.29 (Air = 1) |
| pKa | Not applicable |
| pH | Not applicable |
Phosphorus Oxychloride Safety and Hazards
Phosphoryl chloride poses safety hazards and requires careful handling. It is corrosive to skin, eyes, and respiratory system. Contact can cause severe burns and eye damage. Inhalation of its fumes or vapors can irritate the respiratory tract. Proper personal protective equipment, such as gloves and goggles, should be worn when working with this compound. It should be stored in a well-ventilated area away from sources of ignition. In case of exposure, immediate medical attention is necessary. Furthermore, it should be handled in a fume hood to prevent the release of toxic fumes.
| Hazard Symbols | Corrosive, Hazard |
| Safety Description | Corrosive. Causes severe skin burns and eye damage. May be harmful if inhaled or ingested. Avoid contact and inhalation. |
| UN IDs | UN 1810 |
| HS Code | 2812.10.00 |
| Hazard Class | Class 8 (Corrosive substances) |
| Packing Group | Packing Group III (Minor danger) |
| Toxicity | Phosphoryl chloride is toxic and can cause severe health effects. |
Phosphorus Oxychloride Synthesis Methods
Phosphoryl chloride can be synthesized through various methods. One common method involves the reaction between phosphorus trichloride (PCl3) and oxygen (O2) gas. In this process, PCl3 is heated in the presence of excess oxygen to form phosphoryl chloride. The reaction is exothermic and typically occurs in a controlled environment, such as a reactor vessel.
Another method of synthesis involves the reaction between phosphorus pentoxide (P2O5) and phosphorus trichloride. P2O5 acts as a dehydrating agent, and when combined with PCl3, it forms phosphoryl chloride.
Additionally, phosphoryl chloride can be synthesized through the reaction of phosphorus tribromide (PBr3) and phosphorus pentoxide. This reaction leads to the formation of phosphoryl chloride and phosphorus pentabromide.
Furthermore, the direct chlorination of phosphorus can also yield phosphoryl chloride. In this process, chlorine gas is passed over heated phosphorus, resulting in the formation of phosphoryl chloride.
It’s important to note that these synthesis methods should be carried out with caution due to the reactivity and hazardous nature of the involved compounds. Proper safety protocols, including the use of protective equipment and controlled reaction conditions, should be followed to ensure safe handling and synthesis of phosphoryl chloride.
Phosphorus Oxychloride Uses
Phosphoryl chloride finds various applications across different industries due to its unique properties. Here are some common uses:
- Chemical synthesis: Organic chemistry widely employs phosphoryl chloride as a versatile reagent for producing various compounds, including phosphonic acids, esters, and amides.
- Agrochemicals: The synthesis of pesticides and herbicides in crop protection and pest control relies on phosphoryl chloride as a key ingredient, playing a crucial role.
- Pharmaceutical industry: The manufacturing of pharmaceutical intermediates and active pharmaceutical ingredients (APIs) utilizes phosphoryl chloride, facilitating the synthesis of important drugs like anti-malarial and anti-inflammatory medications.
- Polymer industry: In the production of polymers, phosphoryl chloride acts as a catalyst and chlorinating agent, contributing to the synthesis of flame-retardant additives that enhance the fire resistance of materials.
- Dye and pigment manufacturing: Phosphoryl chloride finds application in the production of dyes and pigments, specifically in the preparation of chloroalkylphosphonates, essential compounds for developing colorants used in textiles, inks, and coatings.
- Laboratory reagent: Various laboratory procedures employ phosphoryl chloride as a reagent, including the conversion of alcohols to alkyl chlorides and the preparation of phosphorylating agents.
- Water treatment: Water treatment processes utilize phosphoryl chloride as an acidifying agent and disinfectant to control pH levels and remove impurities.
- Flame retardants: Phosphoryl chloride plays a role in the production of flame retardant materials, enhancing fire safety properties in textiles, plastics, and construction materials.
These diverse applications demonstrate the significance of phosphoryl chloride in numerous industrial sectors, highlighting its crucial role in chemical synthesis, agriculture, pharmaceuticals, and materials science.
Questions
Q: What is the molecular geometry of POCl3?
A: The molecular geometry of POCl3 is trigonal pyramidal.
Q: What is the major alkene formed when compound A is dehydrated with POCl3 and pyridine?
A: The major alkene formed during the dehydration of compound A with POCl3 and pyridine depends on the specific structure of compound A.
Q: Is POCl3 polar or nonpolar
A: POCl3 is a polar molecule due to the presence of polar bonds and an asymmetric molecular shape.
Q: What volume of POCl3 gas can be produced?
A: The volume of POCl3 gas produced depends on the reactant quantities and the specific reaction conditions.
Q: How many moles of POCl3 are there in 10.0 grams of POCl3?
A: There are approximately 0.082 moles of POCl3 in 10.0 grams of POCl3.
Q: What is the electron-pair geometry for P in POCl3?
A: The electron-pair geometry for P in POCl3 is tetrahedral.
Q: Does POCl3 have a dipole moment?
A: Yes, POCl3 has a dipole moment due to the presence of polar bonds and its molecular geometry.
Q: Does POCl3 have resonance?
A: No, POCl3 does not exhibit resonance as there are no delocalized electrons or multiple resonance structures.
Q: What is the electron domain geometry about the oxygen atom in POCl3?
A: The electron domain geometry around the oxygen atom in POCl3 is trigonal pyramidal.
Q: What volume of H3PO4 will form when 72.3 milliliters of POCl3 completely reacts?
A: The volume of H3PO4 formed when 72.3 milliliters of POCl3 completely reacts depends on the stoichiometry of the reaction and cannot be determined solely based on the given information.