Molar and molecular weight of As(OH)3

• Molecular formula: As(OH)3 or H3AsO3
• Relative molecular weight of As(OH)3: 125.94362
• Molar mass of As(OH)3: 125.94362 g/mol (0.12594 kg/mol)

Calculation of the relative molecular and molar mass of As(OH)3

• Mr[As(OH)3] = Ar[H] * 3 + Ar[As] + Ar[O] * 3 = 1.00794 * 3 + 74.9216 + 15.9994 * 3 = 125.94362
• Molar mass (kg/mol) = Mr[As(OH)3] : 1000 = 125.94362 : 1000 = 0.12594 kg/mol

As(OH)3: percent composition by element

• Hydrogen (H) = 3.02382 : 125.94362 * 100 = 2.401 %
• Arsenic (As) = 74.9216 : 125.94362 * 100 = 59.488 %
• Oxygen (O) = 47.9982 : 125.94362 * 100 = 38.111 %

Molar mass calculator