# Lactose (C12H22O11) Molecular Weight Calculation

The molecular weight of Lactose (C12H22O11) is 342.2978. Lactose (C12H22O11) is an organic compound of three elements: Carbon, Hydrogen, and Oxygen. The molecular weight of Lactose is 342.2978 which can be calculated by adding up the total weight (atomic weight multiplied by their number) of all its elements.

# CALCULATION PROCEDURE: Lactose (C12H22O11) Molecular Weight Calculation

Step 1: Find the chemical formula and determine constituent atoms and their number in a Lactose molecule.
You will know different atoms and their number in a Lactose molecule from the chemical formula. The chemical formula of Lactose is C12H22O11. From the chemical formula, you can find that one molecule of Lactose has twelve Carbon (C) atoms, twenty-two Hydrogen (H) atoms, and eleven Oxygen (O) atoms.

Step 2: Find out the atomic weights of each atom (from the 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 Lactose molecule by multiplying its atomic weight by its number.

Number of Carbon atoms in Lactose: 12
Atomic weight of Carbon: 12.0107
Total weight of Carbon atoms in Lactose: 12.0107 x 12 = 144.1284

Number of Hydrogen atoms in Lactose: 22
Atomic weight of Hydrogen: 1.008
Total weight of Hydrogen atoms in Lactose: 1.008 x 22 = 22.176

Number of Oxygen atoms in Lactose: 11
Atomic weight of Oxygen: 15.9994
Total weight of Oxygen atoms in Lactose: 15.9994 x 11 = 175.9934

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

Molecular weight of Lactose: 144.1284 (Carbon) + 22.176 (Hydrogen) + 175.9934 (Oxygen) = 342.2978

So the molecular weight of Lactose is 342.2978.

Lactose (C12H22O11) 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 