To calculate the atomic mass of Fe(OH)₃ (Iron(III) hydroxide), we will add the atomic masses of the constituent atoms.
- Iron (Fe): 1 atom × 56 amu = 56 amu
- Oxygen (O): 3 atoms × 16 amu = 48 amu (since there are three hydroxide ions, each containing one oxygen atom)
- Hydrogen (H): 3 atoms × 1 amu = 3 amu (again, since there are three hydroxide ions, each containing one hydrogen atom)
Now, add them together:
\[ \text{Total atomic mass} = 56 , \text{amu (Fe)} + 48 , \text{amu (O)} + 3 , \text{amu (H)} = 56 + 48 + 3 = 107 , \text{amu} \]
Therefore, the atomic mass of Fe(OH)₃ is 107 amu.