The molecular weight of 1,2-Butanediol [CH₃CH₂CH(OH)CH₂OH] is 90.1216.

1,2-Butanediol [CH3CH2CH(OH)CH2OH] is an organic compound of three elements: Carbon, Hydrogen, and Oxygen. The molecular weight of 1,2-Butanediol is 90.1216 which can be calculated by adding up the total weight (atomic weight multiplied by their number) of all its elements.

CALCULATION PROCEDURE: 1,2-Butanediol [CH₃CH₂CH(OH)CH₂OH] Molecular Weight Calculation

Step 1: Find out the chemical formula and determine constituent atoms and their number in a 1,2-Butanediol molecule.
You will know different atoms and their number in a 1,2-Butanediol from the chemical formula. The chemical formula of 1,2-Butanediol is C₄H₁₀O₂. From the chemical formula, you can find that one molecule of 1,2-Butanediol has four Carbon (C) atoms, ten 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 1,2-Butanediol molecule by multiplying its atomic weight by its number.

Number of Carbon atoms in 1,2-Butanediol: 4
Atomic weight of Carbon (C): 12.0107
Total weight of Carbon atoms in 1,2-Butanediol: 12.0107 x 4 = 48.0428

Number of Hydrogen atoms in 1,2-Butanediol: 10
Atomic weight of Hydrogen (H): 1.008
Total weight of Hydrogen atoms in 1,2-Butanediol: 1.008 x 10 = 10.08

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

Step 4: Calculate the molecular weight of 1,2-Butanediol by adding up the total weight of all atoms.

Molecular weight of 1,2-Butanediol: 48.0428 (Carbon) + 10.08 (Hydrogen) + 31.9988 (Oxygen) = 90.1216

So the molecular weight of 1,2-Butanediol is 90.1216.

1,2-Butanediol [CH₃CH₂CH(OH)CH₂OH] 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