What is the molecular weight of benzoic acid?

The molecular weight of benzoic acid is 122.12 atomic mass units. The molecular weight of a compound is calculated by adding together the atomic weight of each atom of each element contained in the molecule. The chemical formula for benzoic acid is C7H6O2.

The atomic weight of each carbon atom is about 12 amus, for a total mass of 84 amus in one molecule of benzoic acid. The total atomic mass of hydrogen for each molecule of benzoic acid is about 6 amus. This is calculated by adding 1 amu per atom of hydrogen. The atomic weight of each atom of oxygen is about 16 amus.