The molecular weight of 1,3-Propanediol [CH₂(CH₂OH)₂] is 76.0949.

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: 1,3-Propanediol [CH₂(CH₂OH)₂] Molecular Weight Calculation

Step 1: Find out the chemical formula and determine constituent atoms and their number in a 1,3-Propanediol molecule.
From the chemical formula, you will know different atoms and their number in a 1,3-Propanediol molecule. Chemical formula of 1,3-Propanediol is C₃H₈O₂. From the chemical formula of 1,3-Propanediol, you can find that one molecule of 1,3-Propanediol has three Carbon (C) atoms, eight Hydrogen (H) atoms and two 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 1,3-Propanediol molecule by multiplying its atomic weight by its number.

Number of Carbon atoms in 1,3-Propanediol: 3
Atomic weight of Carbon (C): 12.0107
Total weight of Carbon atoms in 1,3-Propanediol: 12.0107 x 3 = 36.0321

Number of Hydrogen atoms in 1,3-Propanediol: 8
Atomic weight of Hydrogen (H): 1.008
Total weight of Hydrogen atoms in 1,3-Propanediol: 1.008 x 8 = 8.064

Number of Oxygen atoms in 1,3-Propanediol: 2
Atomic weight of Oxygen (O): 15.9994
Total weight of Oxygen atoms in 1,3-Propanediol: 15.9994 x 2 = 31.9988

Step 4: Calculate the molecular weight of 1,3-Propanediol by adding up the total weight of all atoms.

Molecular weight of 1,3-Propanediol: 36.0321 (Carbon) + 8.064 (Hydrogen) + 31.9988 (Oxygen) = 76.0949

So the molecular weight of 1,3-Propanediol is 76.0949.

1,3-Propanediol [CH₂(CH₂OH)₂] 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