What is molecular mass and how to find molecular mass?

Molecular mass

• Molecular mass or molecular weight is the mass of a molecule.
• “The molecular mass of a substance is the sum of the atomic masses of all the atoms in a molecule of the substance”.
• It is expressed in the atomic mass unit(u).

Example

The molecular mass of nitrogen (${\mathrm{N}}_2$) =$2\times \text{Atomic mass of N}$

The molecular mass of nitrogen =$2\times 14.01\text{u}$

=$28.02\text{u}$

So, the molecular mass of nitrogen is $28.02\text{u}$.