The molecular weight of Sodium sulfate decahydrate (Na_{2}SO_{4}.10H_{2}O) (Glauber’s salt) is 322.19713856.

Sodium sulfate (Na_{2}SO_{4}) is an inorganic compound of three elements: Sodium, Sulfur, and Oxygen. The decahydrate form of Sodium sulfate (Na_{2}SO_{4}.10H_{2}O, also known as Glauber’s salt) also contains 10 water molecules. The molecular weight of Sodium sulfate decahydrate is 322.19713856 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 sulfate decahydrate [Na**_{2}SO_{4}.10H_{2}O] Molecular Weight Calculation

_{2}SO

_{4}.10H

_{2}O] Molecular Weight Calculation

**Step 1: Find out the chemical formula and determine constituent atoms and their number in a Sodium sulfate decahydrate molecule. **You will know different atoms and their number in a Sodium sulfate decahydrate molecule from the chemical formula. The chemical formula of Sodium sulfate decahydrate is Na

_{2}SO

_{4}.10H

_{2}O. From the chemical formula, you can find that one molecule of Sodium sulfate decahydrate has two Sodium (Na) atoms, one Sulfur (S) atom, four Oxygen (O) atoms, and ten molecules of water.

**Step 2: Find out the atomic weights of each atom (from the periodic table). **

Atomic weight of Sodium (Na): 22.98976928 (Ref: Ciaaw-sodium)

Atomic weight of Sulfur (S): 32.066 (Ref: Jlab-ele016)

Atomic weight of Oxygen (O): 15.9994 (Ref: Jlab-ele008)

**Step 3: Calculate the molecular weight of Sodium sulfate decahydrate by adding the total weight of all atoms. **

Number of Sodium atoms in Sodium sulfate decahydrate: 2

Atomic weight of Sodium: 22.98976928

Total weight of Sodium atoms in Sodium sulfate decahydrate: 22.98976928 x 2 = 45.97953856

Number of Sulfur (S) atoms in Sodium sulfate decahydrate: 1

Atomic weight of Sulfur: 32.066

Total weight of Sulfur atoms in Sodium sulfate decahydrate: 32.066 x 1 = 32.066

Number of Oxygen (O) atoms in Sodium sulfate decahydrate: 4

Atomic weight of Oxygen: 15.9994

Total weight of Oxygen atoms in Sodium sulfate decahydrate: 15.9994 x 4 = 63.9976

Number of water (H_{2}O) molecules in Potassium antimonyl tartrate trihydrate: 10

Molecular weight of water: 18.0154

Total weight of water in Potassium antimonyl tartrate trihydrate: 18.0154 x 10 = 180.154

**Step 4: Calculate the molecular weight of Sodium sulfate decahydrate by adding up the total weight of all atoms. **

Molecular weight of Sodium sulfate decahydrate : 45.97953856 (Sodium) + 32.066 (Sulfur) + 63.9976 (Oxygen) + 180.154 (water) = 322.19713856

So the molecular weight of Sodium sulfate decahydrate is 322.19713856.

Sodium sulfate decahydrate [Na_{2}SO_{4}.10H_{2}O] Molecular Weight Calculation 322.19713856

Molecular weight of Sodium sulfate decahydrate (Na_{2}SO_{4}.10H_{2}O) | |||

Constituent atoms | Number of each atom | Atomic weight | Total weight |

Sodium (Na) | 2 | 22.98976928 | 45.97953856 |

Sulfur (S) | 1 | 32.066 | 32.066 |

Oxygen (O) | 4 | 15.9994 | 63.9976 |

Water (H_{2}O) | 10 | 18.0154 | 180.154 |

Molecular weight of Sodium sulfate decahydrate (Na_{2}SO_{4}.10H_{2}O): | 322.19713856 |

## REFERENCES:

- Ciaaw-sodium : https://www.ciaaw.org/sodium.htm
- Jlab-ele016: https://education.jlab.org/itselemental/ele016.html
- Jlab-ele008: https://education.jlab.org/itselemental/ele008.html