The molecular weight of Lactaldehyde [C₃H₆O₂] is 74.0789.

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: Lactaldehyde [C₃H₆O₂] Molecular Weight Calculation

Step 1: Find out the chemical formula and determine constituent atoms and their number in a Lactaldehyde molecule.
From the chemical formula, you will know different atoms and their number in a Lactaldehyde molecule. Chemical formula of Lactaldehyde is C₃H₆O₂. From the chemical formula of Lactaldehyde, you can find that one molecule of Lactaldehyde has three Carbon (C) atoms, six 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 Lactaldehyde molecule by multiplying its atomic weight by its number.

Number of Carbon atoms in Lactaldehyde: 3
Atomic weight of Carbon (C): 12.0107
Total weight of Carbon atoms in Lactaldehyde: 12.0107 x 3 = 36.0321

Number of Hydrogen atoms in Lactaldehyde: 6
Atomic weight of Hydrogen (H): 1.008
Total weight of Hydrogen atoms in Lactaldehyde: 1.008 x 6 = 6.048

Number of Oxygen atoms in Lactaldehyde: 2
Atomic weight of Oxygen (O): 15.9994
Total weight of Oxygen atoms in Lactaldehyde: 15.9994 x 2 = 31.9988

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

Molecular weight of Lactaldehyde: 36.0321 (Carbon) + 6.048 (Hydrogen) + 31.9988 (Oxygen) = 74.0789

So the molecular weight of Lactaldehyde is 74.0789.

Lactaldehyde [C₃H₆O₂] 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