The molecular weight of Glycolic acid [HOCH2CO2H] is 76.3503.

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: Glycolic acid [HOCH2CO2H] Molecular Weight Calculation

Step 1: Find out the chemical formula and determine constituent atoms and their number in a Glycolic acid molecule.
From the chemical formula, you will know different atoms and their number in a Glycolic acid molecule. Chemical formula of Glycolic acid is C₂H₄O₃. From the chemical formula of Glycolic acid, you can find that one molecule of Glycolic acid has two Carbon (C) atoms, four Hydrogen (H) atoms and three Oxygen (O) atoms.

Step 2: Find out atomic weights of each atom (from 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 present in a Glycolic acid molecule by multiplying its atomic weight by its number.

Number of Carbon atoms in Glycolic acid: 2
Atomic weight of Carbon: 12.0107
Total weight of Carbon atoms in Glycolic acid: 12.0107 x 2 = 24.0321

Number of Hydrogen atoms in Glycolic acid: 4
Atomic weight of Hydrogen: 1.008
Total weight of Hydrogen atoms in Glycolic acid: 1.008 x 4 = 4.032

Number of Oxygen atoms in Glycolic acid: 3
Atomic weight of Oxygen: 15.9994
Total weight of Oxygen atoms in Glycolic acid: 15.9994 x 3 = 47.9982

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

Molecular weight of Glycolic acid: 24.0321 (Carbon) + 4.032 (Hydrogen) + 47.9982 (Oxygen) = 76.3503

So the molecular weight of Glycolic acid is 76.3503.

Glycolic acid [HOCH2CO2H] 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