- Books Name
- Science Made Easy Science Book
- Publication
- Science Made Easy
- Course
- CBSE Class 9
- Subject
- Science
Molecular Mass
→ It is the sum of atomic masses of all the atoms in a molecule of that substance.
Example: Molecular mass of H2O = 2×Atomic mass of Hydrogen + 1×Atomic mass of Oxygen
So, Molecular mass of H2O = 2×1 + 1×16 = 18 u
Formula Unit Mass
→ It is the sum of atomic mass of ions and atoms present in formula for a compound.
Example: In NaCl,
Na = 23 a.m.u.
Cl = 35.5 a.m.u.
So, Formula unit mass = 1×23
+ 1×35.5 = 58.5 u