The molecular weight of Hydrogen peroxide [O₂] is 31.9988.

To calculate molecular weight of any compound, the first step is to know the constituent atoms and their number in that particular compound. Then calculate the total weight of each atom by multiplying its atomic weight by its number. The sum of total weight of all constituent atoms will be the molecular weight of the compound. Note that the value of atomic weight may differ slightly from different sources.

CALCULATION PROCEDURE: Oxygen [O₂] Molecular Weight Calculation

Step 1: Find out the chemical formula and determine constituent atoms and their number in a Oxygen molecule.
From the chemical formula, you will know different atoms and their number in a Oxygen molecule. Chemical formula of Oxygen is O₂. From the chemical formula of Oxygen, you can find that one molecule of Oxygen has two Oxygen (O) atoms.

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

Atomic weight of Oxygen (O) atom: 15.9994 (Ref: Jlab-ele008)

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

Number of Oxygen atoms in Oxygen molecule: 2
Atomic weight of Oxygen atom: 15.9994
Total weight of Oxygen atoms in a Oxygen molecule: 15.9994 x 2 = 31.9988

Since a oxygen molecule cantain just 2 oxygen atoms, the molecular weight of Oxygen (O₂) molecule is 31.9988.

So the molecular weight of Oxygen is 31.9988.

Oxygen [O₂] Molecular Weight Calculation

REFERENCES:

• 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