ChemistryCLASS 10CBSE
answered 28 May 2026What is molecular mass, and how is it calculated?
A.VERIFIED ANSWERfact-checked by tutors
Molecular mass is the sum of the atomic masses of all atoms in one molecule of a substance, expressed in atomic mass units (u) or g/mol.
Example: Water (H₂O):
| Element | No. of Atoms | Atomic Mass | Total |
|---|---|---|---|
| H | 2 | 1 | 2 |
| O | 1 | 16 | 16 |
| Molecular Mass | 18 u |
Steps: Write formula → count atoms → multiply by atomic mass → add all values.
Molecular mass is calculated by adding the atomic masses of all atoms in a molecule, using their quantities as per the formula.