Phosphorus trichloride is a chemical compound consisting of phosphorus and three chlorine atoms. It is commonly used as a reagent in chemical reactions and as a precursor for organophosphorus compounds.
| IUPAC Name | Phosphorus trichloride |
| Molecular Formula | PCl3 |
| CAS Number | 7719-12-2 |
| Synonyms | Trichlorophosphine, Phosphorous chloride, Phosphorous trichloride, Phosphorous(III) chloride |
| InChI | InChI=1S/Cl3P/c1-4(2)3 |
Phosphorus Trichloride Properties
Phosphorus Trichloride Formula
The formula of phosphorus trichloride is PCl3. It consists of one phosphorus atom bonded to three chlorine atoms. This chemical compound is widely used in various industries and laboratories for its reactivity and versatility.
Phosphorus Trichloride Molar Mass
The molar mass of trichlorophosphine can be calculated by adding the atomic masses of its constituent elements. Phosphorus has an atomic mass of approximately 31.0 grams per mole, while chlorine has an atomic mass of around 35.5 grams per mole. Therefore, the molar mass of PCl3 is approximately 137.3 grams per mole.
Phosphorus Trichloride Boiling Point
Trichlorophosphine has a boiling point of around 76.1 degrees Celsius. This means that when heated, it transforms from a liquid to a gas. The boiling point is an important property to consider when handling and using trichlorophosphine in various chemical reactions and processes.
Phosphorus Trichloride Melting Point
The melting point of trichlorophosphine is approximately -112.7 degrees Celsius. It undergoes a phase transition from a solid to a liquid at this temperature. The melting point is a crucial characteristic for determining the physical state of trichlorophosphine under different conditions.
Phosphorus Trichloride Density g/mL
The density of trichlorophosphine is approximately 1.574 grams per milliliter. Density represents the mass of a substance per unit volume and provides insights into the compactness and heaviness of the material. The density of trichlorophosphine is often utilized in chemical calculations and formulations.
Phosphorus Trichloride Molecular Weight
The molecular weight of trichlorophosphine, calculated by adding the atomic weights of its constituents, is approximately 137.3 grams per mole. The molecular weight is a valuable parameter for determining the amount of substance in chemical reactions and formulating precise measurements.
Phosphorus Trichloride Structure
Trichlorophosphine adopts a trigonal pyramidal structure, where the phosphorus atom occupies the apex and the three chlorine atoms form a triangular base. This molecular arrangement contributes to its chemical reactivity and influences its behavior in various reactions.
Phosphorus Trichloride Solubility
Trichlorophosphine is sparingly soluble in water, but it dissolves readily in organic solvents such as benzene and carbon tetrachloride. The solubility properties of trichlorophosphine are essential considerations when determining suitable solvents for its use in different chemical processes and applications.
| Appearance | Colorless or pale yellow liquid |
| Specific Gravity | 1.574 g/mL |
| Color | Colorless |
| Odor | Pungent |
| Molar Mass | 137.3 g/mol |
| Density | 1.574 g/mL |
| Melting Point | -112.7 °C |
| Boiling Point | 76.1 °C |
| Flash Point | Not applicable (Non-flammable) |
| Water Solubility | Reacts with water |
| Solubility | Soluble in organic solvents such as benzene and carbon tetrachloride |
| Vapor Pressure | 105 mmHg at 25 °C |
| Vapor Density | 4.83 (Air = 1) |
| pKa | Not applicable |
| pH | Acidic (pH < 7) |
Phosphorus Trichloride Safety and Hazards
Trichlorophosphine poses several safety hazards and must be handled with caution. It is highly corrosive to the skin, eyes, and respiratory system. Direct contact can cause severe burns and eye damage. Inhalation of its vapors may lead to respiratory irritation and lung damage. Additionally, trichlorophosphine reacts violently with water, releasing toxic fumes of hydrochloric acid. It is flammable in certain conditions, and contact with oxidizing agents can cause fires or explosions. Adequate personal protective equipment, such as gloves, goggles, and a respirator, should be used when working with this chemical. Proper ventilation and storage away from incompatible substances are crucial for minimizing risks.
| Hazard Symbols | Corrosive, Toxic |
| Safety Description | – Causes severe skin burns and eye damage – Harmful if swallowed, inhaled, or absorbed – Reacts violently with water, releasing toxic fumes – Flammable under certain conditions |
| Un IDs | UN1809 |
| HS Code | 2812.10.00 |
| Hazard Class | 8 (Corrosive), 6.1 (Toxic) |
| Packing Group | II |
| Toxicity | Highly toxic |
Phosphorus Trichloride Synthesis Methods
Various methods synthesize trichlorophosphine. One common approach involves heating phosphorus with excess chlorine gas, leading to the formation of trichlorophosphine.
Another method entails heating phosphorus pentachloride (PCl5) with trichlorophosphine (PCl3) to produce trichlorophosphine.
The reaction between phosphorus oxide (P2O5) and hydrochloric acid (HCl) combines the two substances, typically with a reflux condenser, to facilitate the synthesis of trichlorophosphine.
Additionally, heating phosphorus tribromide (PBr3) with trichlorophosphine results in the production of trichlorophosphine.
It is important to note that the synthesis of trichlorophosphine should be conducted with appropriate safety precautions, as it involves the handling of reactive and hazardous substances. Ensure safety during the synthesis process by employing proper protective equipment and maintaining well-ventilated laboratory conditions.
Overall, these various synthesis methods offer different approaches to obtaining trichlorophosphine, providing flexibility in its production for a wide range of industrial and research applications.
Phosphorus Trichloride Uses
Trichlorophosphine finds extensive use in several applications due to its versatile nature and reactivity. Here are some key uses:
- Chemical Reagent: It serves as an important reagent in organic synthesis, especially in the production of organophosphorus compounds. It participates in reactions like the Vilsmeier-Haack reaction and the Pudovik reaction.
- Catalyst: Trichlorophosphine acts as a catalyst in various chemical reactions, including the synthesis of pharmaceuticals, dyes, and pesticides.
- Phosphorus Source: It serves as a source of phosphorus in the production of phosphorous-based chemicals like phosphorous acid and phosphorous oxychloride.
- Flame Retardant: Manufacturers add trichlorophosphine as a flame retardant to polymers, enabling the reduction of flammability and improvement of fire safety in materials.
- Chemical Intermediate: Various chemicals, including pharmaceuticals, herbicides, insecticides, and plasticizers, undergo production using trichlorophosphine as a crucial intermediate.
- Laboratory Reagent: Laboratories widely employ trichlorophosphine as a versatile reagent for chemical reactions, including the formation of acyl chlorides and the conversion of alcohols to alkyl chlorides.
- Water Treatment: The strong oxidizing and chlorinating properties of trichlorophosphine make it a valuable component in water treatment processes, effectively removing impurities and contaminants.
- Pharmaceuticals: Trichlorophosphine plays a role in the synthesis of pharmaceutical compounds, including drugs for treating cancer, inflammation, and neurological disorders.
- Agricultural Applications: It finds application in agriculture as a component of certain pesticides and herbicides, assisting in crop protection and weed control.
- Plastic Manufacturing: Manufacturers utilize trichlorophosphine in the production of plastics and polymer additives to enhance material properties and provide flame retardancy.
These diverse applications highlight the significance of trichlorophosphine in various industries, research, and everyday applications.
Questions:
Q: Is phosphorus trichloride a base or acid?
A: Trichlorophosphine is an acid.
Q: How many atoms of chlorine are in a molecule of phosphorus trichloride, PCl3?
A: There are three atoms of chlorine in a molecule of trichlorophosphine.
Q: What is the percent yield of a reaction in which 200g of phosphorus trichloride reacts?
A: The percent yield cannot be determined without information about the amount of the product obtained.
Q: How many moles are in 15 grams of phosphorus trichloride?
A: There are approximately 0.116 moles of trichlorophosphine in 15 grams.
Q: Which formula represents the binary molecular compound phosphorus trichloride?
A: The formula PCl3 represents trichlorophosphine.
Q: What is the formula for phosphorus trichloride?
A: The formula for phosphorus trichloride is PCl3.
Q: Is phosphorus trichloride ionic or covalent?
A: Trichlorophosphine is a covalent compound.
Q: How many atoms of chlorine are in a molecule of phosphorus trichloride, PCl3?
A: There are three atoms of chlorine in a molecule of trichlorophosphine.
Q: Trichlorophosphine Lewis structure?
A: The Lewis structure of trichlorophosphine features a central phosphorus atom bonded to three chlorine atoms, with lone pairs on the phosphorus atom.
Q: Phosphorus (P4) (s) + Chlorine (g) → Trichlorophosphine (l)?
A: The balanced equation represents the reaction between solid phosphorus (P4) and chlorine gas (Cl2) to form liquid PCl3.
Q: What is the shape of phosphorus trichloride?
A: Trichlorophosphine has a trigonal pyramidal shape due to the presence of one lone pair of electrons on the phosphorus atom.
Q: Is phosphorus trichloride an ionic compound?
A: No, trichlorophosphine is not an ionic compound; it is a covalent compound.
Q: Does phosphorus trichloride have reflection planes?
A: No, trichlorophosphine does not have reflection planes.