The molecular weight of Benzoic acid [C₇H₆O₂] is 122.1217.

Benzoic acid [C₇H₆O₂] is an organic compound of three elements: Carbon, Hydrogen, and Oxygen. The molecular weight of Benzoic acid is 122.1217 which can be calculated by adding up the total weight (atomic weight multiplied by their number) of Carbon, Hydrogen, and Oxygen.

CALCULATION PROCEDURE: Benzoic acid [C₇H₆O₂] Molecular Weight Calculation

Step 1: Find out the chemical formula and determine constituent atoms and their number in a Benzoic acid molecule.
From the chemical formula, you will know different atoms and their number in a Benzoic acid molecule. The chemical formula of Benzoic acid is C₇H₆O₂. From the chemical formula, you can find that one molecule of Benzoic acid has seven Carbon (C) atoms, six Hydrogen (H) atoms, and two Oxygen (O) atoms.

Step 2: Find out the atomic weights of each atom (from the periodic table).

Atomic weight of Carbon (C): 12.0107 (Ref: Jlab-ele006)
Atomic weight of Hydrogen (H): 1.008 (Ref: Lanl-1)
Atomic weight of Oxygen (O): 15.9994 (Ref: Jlab-ele008)

Step 3: Calculate the total weight of each atom in a Benzoic acid molecule by multiplying its atomic weight by its number.

Number of Carbon atoms in Benzoic acid: 7
Atomic weight of Carbon: 12.0107
Total weight of Carbon atoms in Benzoic acid: 12.0107 x 7 = 84.0749

Number of Hydrogen atoms in Benzoic acid: 6
Atomic weight of Hydrogen: 1.008
Total weight of Hydrogen atoms in Benzoic acid: 1.008 x 6 = 6.048

Number of Oxygen atoms in Benzoic acid: 2
Atomic weight of Oxygen: 15.9994
Total weight of Oxygen atoms in Benzoic acid: 15.9994 x 2 = 31.9988

Step 4: Calculate the molecular weight of Benzoic acid by adding up the total weight of all atoms.

Molecular weight of Benzoic acid: 84.0749 (Carbon) + 6.048 (Hydrogen) + 31.9988 (Oxygen) = 122.1217

So the molecular weight of Benzoic acid is 122.1217.

Benzoic acid [C₇H₆O₂] Molecular Weight Calculation

REFERENCES:

• Lanl-1: https://periodic.lanl.gov/1.shtml 
• Pubchem-Hydrogen : https://pubchem.ncbi.nlm.nih.gov/element/Hydrogen 
• Jlab-ele006; https://education.jlab.org/itselemental/ele006.html
• Pubchem-6: https://pubchem.ncbi.nlm.nih.gov/element/6
• Jlab-ele008: https://education.jlab.org/itselemental/ele008.html
• Pubchem-8: https://pubchem.ncbi.nlm.nih.gov/element/8

See also:

• Apiose (C5H10O5) Molecular Weight Calculation