Molar and molecular weight of OsO4

• Molecular formula: OsO4 or O4Os
• Relative molecular weight of OsO4: 254.2276
• Molar mass of OsO4: 254.2276 g/mol (0.25423 kg/mol)

Calculation of the relative molecular and molar mass of OsO4

• Mr[OsO4] = Ar[O] * 4 + Ar[Os] = 15.9994 * 4 + 190.23 = 254.2276
• Molar mass (kg/mol) = Mr[OsO4] : 1000 = 254.2276 : 1000 = 0.25423 kg/mol

OsO4: percent composition by element

• Oxygen (O) = 63.9976 : 254.2276 * 100 = 25.173 %
• Osmium (Os) = 190.23 : 254.2276 * 100 = 74.827 %

Molar mass calculator