The molecular weight of Ethanol (C₂H₅OH) is 46.0688.

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: Ethanol (C₂H₅OH) Molecular Weight Calculation

Step 1: Find out the chemical formula and determine constituent atoms and their number in a Ethanol molecule.
From the chemical formula, you will know different atoms and their number in a Ethanol molecule. Chemical formula of Ethanol is C₂H₆O. From the chemical formula of Ethanol, you can find that one molecule of Ethanol has two Carbon (C) atoms, six Hydrogen (H) atoms and one Oxygen (O) atom.

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 Ethanol molecule by multiplying its atomic weight by its number.

Number of Carbon atoms in Ethanol: 2
Atomic weight of Carbon: 12.0107
Total weight of Carbon atoms in Ethanol: 12.0107 x 2 = 24.0214

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

Number of Oxygen atoms in Ethanol: 1
Atomic weight of Oxygen: 15.9994
Total weight of Oxygen atoms in Ethanol: 15.9994 x 1 = 15.9994

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

Molecular weight of Ethanol: 24.0214 (Carbon) + 6.048 (Hydrogen) + 15.9994 (Oxygen) = 46.0688

So the molecular weight of Ethanol is 46.0688.

Ethanol (C₂H₅OH) 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