Question

Calculate the molar mass of H₃PO_4.

Answer 1

1. Molar mass is the sum of the masses of all the individual atoms present in a molecule or compound.
2. Orthophosphoric acid is the important acid of oxygen and phosphorous.
3. It is used for making phosphate salts for fertilizers.
4. Chemical formula of Orthophosphoric acid is H₃PO_4.
5. Atomic mass of Oxygen O is 16 u.
6. Atomic mass of hydrogen H is 1 u.
7. Atomic mass of Phosphorous P is 31 u.

Molecular mass of Orthophosphoric acid H₃PO₄ = (Atomic mass of Hydrogen) x 3 + (Atomic mass of Phosphorous) x 1 + (Atomic mass of Oxygen) x 4

= ( 1 x 3 ) + ( 31 x 1 ) + ( 16 x 4 )

= 3 + 31 + 64

= 98 u.

Molecular mass of Orthophosphoric acid H₃PO₄ is 98 u.