Question

Differentiate between molecular mass and formula unit mass.

Answer 1

Molecular mass	Formula unit mass
It is the sum of the masses of all the atoms in a molecule.	It is the sum of the masses of all ions present in the formula unit of a compound.
It is used for those compounds that contain only non metals.	It is used for those compounds that contain metals and non metals.
Eg. Water ($H_{2}O$) has molecular mass of 18 u.	Eg. Sodium chloride ($NaCl$) has formula unit mass of 58.5 u.