The gram molecular mass of phosphorus is (Note: GAW of P=31 g)           

The gram atomic weight (GAW) of phosphorus is given as 31 g. This value represents the mass of one mole of individual phosphorus atoms. However, in nature, phosphorus commonly exists in molecular form as P₄, where four phosphorus atoms combine to form a single molecule.

To calculate the gram molecular mass of P₄, we multiply the gram atomic weight of phosphorus by the number of atoms in the molecule:

Gram Molecular Mass of P₄ = 4 × Gram Atomic Weight of P

Substituting the values:

Gram Molecular Mass of P₄ = 4 × 31 g = 124 g

Therefore, the gram molecular mass of phosphorus (P₄) is 124 g. This calculation helps in determining the molar mass of phosphorus molecules, commonly referred to as P molar mass, which is essential in various chemical and stoichiometric calculations.

Also Check: Atomic & Molecular Mass

Key Notes

• The term P molar mass refers to the molar mass of molecular phosphorus (P₄), which is 124 g/mol.
• The calculation considers the molecular form of phosphorus (P₄), not the atomic form.
• Understanding the P molar mass is crucial for accurate quantitative chemical analysis.