The molecular weight of Sodium acetate trihydrate [CH₃COONa.3H2O] is 136,08.

Sodium acetate (CH₃COONa) is an organic compound of four elements: Carbon, Hydrogen, Sodium, and Oxygen. The trihydrate form of Sodium acetate (CH₃COONa.3H2O) also contains 3 water molecules. The molecular weight of Sodium acetate trihydrate is 136,08 which can be calculated by adding up the total weight (atomic weight multiplied by their number) of all its elements and water molecules.

CALCULATION PROCEDURE: Sodium acetate trihydrate [CH₃COONa.3H2O] Molecular Weight Calculation

Step 1: Find out the chemical formula and determine constituent atoms and their number in a Sodium acetate trihydrate molecule.
You will know different atoms and their number in a Sodium acetate trihydrate molecule from the chemical formula. The chemical formula of Sodium acetate trihydrate is C₂H₃O₂Na. From the chemical formula, you can find that one molecule of Sodium acetate trihydrate has two Carbon (C) atoms, three Hydrogen (H) atoms, two Oxygen (O) atoms, one Sodium (Na) atom, and three water molecules.

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)
Atomic weight of Sodium (Na): 22.98976928 (Ref: Ciaaw-sodium)
Molecular weight of Water [H2O]: 18.0154

Step 3: Calculate the total weight of each atom in a Sodium acetate trihydrate molecule by multiplying its atomic weight by its number.

Number of Carbon atoms in Sodium acetate trihydrate: 2
Atomic weight of Carbon (C): 12.0107
Total weight of Carbon atoms in Sodium acetate trihydrate: 12.0107 x 2 = 24.0214

Number of Hydrogen atoms in Sodium acetate trihydrate: 3
Atomic weight of Hydrogen (H): 1.008
Total weight of Hydrogen atoms in Sodium acetate trihydrate: 1.008 x 3 = 3.024

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

Number of Sodium atoms in Sodium acetate trihydrate: 1
Atomic weight of Sodium (Na): 22.98976928
Total weight of Sodium atoms in Sodium acetate trihydrate: 22.98976928 x 1 = 22.98976928

Number of water (H₂O) molecules in Sodium acetate trihydrate: 3
Molecular weight of water: 18.0154
Total weight of water in Sodium acetate trihydrate: 18.0154 x 3 = 54.0462

Step 4: Calculate the molecular weight of Sodium acetate trihydrate by adding up the total weight of all atoms.

Molecular weight of Sodium acetate trihydrate: 24.0214 (Carbon) + 3.024 (Hydrogen) + 31.9988 (Oxygen) + 22.98976928 (Sodium) + 54.0462 (Water)= 136,08

So the molecular weight of Sodium acetate trihydrate is 136,08.

Sodium acetate trihydrate [CH₃COONa.3H2O] Molecular Weight Calculation

REFERENCES:

• Lanl-1: https://periodic.lanl.gov/1.shtml 
• Jlab-ele006; https://education.jlab.org/itselemental/ele006.html
• Jlab-ele008: https://education.jlab.org/itselemental/ele008.html
• Ciaaw-sodium : https://www.ciaaw.org/sodium.htm

See also:

• Apiose (C5H10O5) Molecular Weight Calculation