The molecular weight of Melibiose (C₁₂H₂₂O₁₁) is 342.2978.

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: Melibiose (C₁₂H₂₂O₁₁) Molecular Weight Calculation

Step 1: Find out the chemical formula and determine constituent atoms and their number in a Melibiose molecule.
From the chemical formula, you will know different atoms and their number in a Melibiose molecule. Chemical formula of Melibiose is C₁₂H₂₂O₁₁. From the chemical formula of Melibiose, you can find that one molecule of Melibiose has twelve Carbon (C) atoms, twenty-two Hydrogen (H) atoms and eleven 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 Melibiose molecule by multiplying its atomic weight by its number.

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

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

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

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

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

So the molecular weight of Melibiose is 342.2978.

Melibiose (C₅H₁₀O₅) 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