Molar and molecular weight of FeSO3

• Molecular formula: FeSO3 or FeO3S
• Relative molecular weight of FeSO3: 135.9082
• Molar mass of FeSO3: 135.9082 g/mol (0.13591 kg/mol)

Calculation of the relative molecular and molar mass of FeSO3

• Mr[FeSO3] = Ar[Fe] + Ar[O] * 3 + Ar[S] = 55.845 + 15.9994 * 3 + 32.065 = 135.9082
• Molar mass (kg/mol) = Mr[FeSO3] : 1000 = 135.9082 : 1000 = 0.13591 kg/mol

FeSO3: percent composition by element

• Iron (Fe) = 55.845 : 135.9082 * 100 = 41.09 %
• Oxygen (O) = 47.9982 : 135.9082 * 100 = 35.317 %
• Sulfur (S) = 32.065 : 135.9082 * 100 = 23.593 %

Molar mass calculator