Explanation:
Molecular mass is defined as the sum of atomic masses of all the atoms present in a given compound.
For example, molecular mass of [tex]CH_{4}[/tex] is as follows.
= [tex]\text{atomic mass of C} + 4 \times \text{atomic mass of H}[/tex]
= [tex]12.0 g/mol + 4 \times 1 g/mol[/tex]
= (12 + 4) g/mol
= 16 g/mol
Hence, the molecular mass of [tex]CH_{4}[/tex] is 16 g/mol.
Therefore, we can conclude that the sum of the atomic masses of all the atoms in a formula for a covalent compound is the molecular mass.