Allotrophic Forms of Phosphorus

There are many different types of allotropes of elements, which are also known as allotropes of elements. Allotropy or allotropism is the property of some chemical elements to exist in two or more different forms, while remaining in the same physical state, which are known as allotropes of elements. As a result, the physical and chemical properties of some elements in the periodic table differ from one another. Among the elements of the periodic table that exhibit allotropism are carbon and phosphorus, to name just a couple.

Phosphorus comes in a variety of forms.

Phosphorus exhibits a variety of allotropes in different forms. The following are some of the most important phosphorus allotropes:

1. Black Phosphorus 
2. White Phosphorus 
3. Red Phosphorus

Black Phosphorus 

Red phosphorus is transformed into black phosphorus by heating it to 416 degrees Celsius. It is only when red phosphorus is heated in a sealed tube at the proper temperature that it is transformed into black phosphorus. When the white form of phosphorus is heated under high pressure at 473 degrees Celsius, the formation of black phosphorus occurs.

Physical properties of Black Phosphorus 

• Phosphorus is a dark metal with a black appearance.
• Approximately 416 degrees Celsius is the melting point of black phosphorus.
• The specific gravity of black phosphorus is 2.69 times greater than that of white phosphorus.
• In terms of mass per mole, the exact mass of black phosphorus is 30.973762 g/mole.
• The density of black phosphorus is 2.34 g/cm3 (grams per cubic centimeter).
• Black phosphorus is soluble in water (H2O) to a concentration of 0.3 g/l.
• Black phosphorus has a molecular weight of 30.97 and is a compound element.
• Black phosphorus can be found in both crystalline and amorphous forms, depending on the source.

Chemical properties of  black phosphorus

• The allotrope of phosphorus known as black phosphorus is the most stable of all the allotropes of phosphorus.
• The allotrope of phosphorus known as black phosphorus is the least reactive of all the phosphorus allotropes.

Chemical Structure of Black Phosphorus 

The following bullet points summarize the basic chemical structure of black phosphorus in a concise manner:

• The structure of black phosphorus is characterized by zig-zag lines of P – P bonds.
• The structure of black phosphorus resembles a honeycomb, and as a result, it is also referred to as a honeycomb structure. 
• The bond angle between the black phosphorus and the other elements is 99 degrees. 
• Black phosphorus has a bond length of 218 Pm, which is very long.

White Phosphorus 

White phosphorus is also referred to as Tetra Phosphorus and Yellow Phosphorus, among other names. White phosphorus is not obtained naturally; rather, it is produced artificially from phosphate rocks..

Physical properties of White Phosphorus  

• Because it is translucent, white phosphorus has the appearance of a waxy solid.
• White phosphorus has a garlic-like odour, which means it has a garlic-like odour when it is crushed.
• White phosphorus is referred to as a polar compound because it is not soluble in water, but is soluble in carbon dioxide when exposed to high temperatures.
• The molecular weight of white phosphorus is 30.97 g/mole.
• White phosphorus occurs naturally and is highly toxic and corrosive.

Chemical properties  of White Phosphorus

• When white phosphorus reacts with a metal, the result is metal phosphide, which is a toxic gas.
• White phosphorus reacts with the oxygen in the air and causes a fire to erupt as a result of the reaction. In order to avoid this, white phosphorus is stored beneath the surface of the water. 
• It is possible to produce red phosphorus by heating white phosphorus at 573 degrees Celsius in an inert atmosphere for several days at a time.

Chemical structure of white phosphorus

• White phosphorus is made up of four atoms of phosphorus that are all linked together by a covalent bond.
• White phosphorus has a ring-like structure in its crystal structure.
• The white phosphorus bond has a 60-degree angle with the rest of the bond.

Red Phosphorous 

It is possible to produce red phosphorus by heating the white phosphorus to a high temperature of around 573 K in an inert atmosphere for several days, which is a different allotrope of the chemical element phosphorus.

Physical properties of Red Phosphorus 

• Red Phosphorus is a deep red mineral that, as its name suggests, is toxic.
• Red phosphorus has no discernible odor.
• Red phosphorus is non-toxic in its natural state.
• Red phosphorus has a melting point of 860 degrees Celsius.
• The red phosphorus has a molecular weight of 30.97 g/mol and is composed primarily of phosphorus.
• Red Phosphorus does not emit any visible light when exposed to darkness.

Chemical properties of red phosphorus

• Red phosphorus reacts with oxygen only at 565 degrees Celsius, resulting in phosphorus pentoxide. 
• Red phosphorus reacts with oxygen only at 565 degrees Celsius.
• Sulfur reacts with red phosphorus, resulting in the formation of sulphides.

Chemical Structure of Red Phosphorus 

• Red Phosphorus has a structure that is very similar to that of Black Phosphorus.
• Red phosphorus occurs naturally as a polymeric compound.
• Each phosphorus atom in the P4 molecule is connected to three other phosphorus atoms through a covalent bond, forming a tetrahedral structure.

Conclusion

In nature, phosphorus exists in a variety of allotropic forms. White phosphorus, black phosphorus, and red phosphorous are the three most important allotropic forms of phosphorus in nature.Allotropy or allotropism is the property of some chemical elements to exist in two or more different forms, while remaining in the same physical state, which are known as allotropes of elements. As a result, the physical and chemical properties of some elements in the periodic table differ from one another. Black Phosphorus is a dark metal with a black appearance and  approximately 416 degrees. Celsius is the melting point of black phosphorus.White phosphorus reacts with the oxygen in the air and causes a fire to erupt as a result of the reaction. In order to avoid this, white phosphorus is stored beneath the surface of the water.Red Phosphorus is a deep red mineral that, as its name suggests, is toxic. Red phosphorus has no discernible odour.