Question

Calculate the molar mass of ${{H}_{3}}P{{O}_{4}}$ .

Answer 1

Hint: The addition of the individual atomic or molecular weights of the elements which are present in the molecular or chemical formula is called molar mass or molecular weight. We have to consider each and every element at the time of calculation of the molar mass of a chemical.
Complete step by step answer:
- In the question it is asked to calculate the molar mass of the ${{H}_{3}}P{{O}_{4}}$ .
- ${{H}_{3}}P{{O}_{4}}$ is also called phosphoric acid.
- To calculate the molar mass of any chemical first we should know the molecular weight of the individual elements which are present in the given compound.
- The individual elements which are present in the phosphoric acid are hydrogen, phosphorus and oxygen.
- Phosphoric acid contains three hydrogens, one phosphorus atom and three oxygen atoms.
- The molecular weights of hydrogen, phosphorus and oxygen are 1, 31 and 16 respectively.
- Therefore the molecular weight of the phosphoric acid is as follows.
3 (H) + (P) + 4(O) = 3 (1) + 31 + 4(16) = 3 + 31 + 64 = 98.
- So, the molecular weight or molar mass of the phosphoric acid is 98.

Note: Equivalent weight is different from the molecular weight of the substance. The equivalent weight of a chemical is going to depend on the acidity or basicity of the atoms in the given molecule. We have to consider all the elements' atomic weights at the time of calculation of the molecular weight of the compound.