To determine the total mass of the reactants in the reaction \( \text{FeCl}_3 + 3\text{H}_2\text{O} \), we first need to calculate the molar mass of each reactant individually.
-
Calculate the mass of \(\text{FeCl}_3\):
- Mass of Fe (Iron) = 56 amu
- Mass of Cl (Chlorine) = 35 amu (there are 3 Cl atoms in \(\text{FeCl}_3\))
- Total mass of \(\text{FeCl}_3\):
\[ \text{Mass of FeCl}_3 = \text{Mass of Fe} + 3 \times \text{Mass of Cl} = 56 + 3 \times 35 \] \[ = 56 + 105 = 161 , \text{amu} \]
-
Calculate the mass of \(3\text{H}_2\text{O}\):
- Mass of H (Hydrogen) = 1 amu (there are 2 H atoms in each water molecule and we have 3 water molecules, so 6 H in total)
- Mass of O (Oxygen) = 16 amu (there is 1 O atom in each water molecule and we have 3 water molecules, so 3 O in total)
- Total mass of \(3\text{H}_2\text{O}\):
\[ \text{Mass of } 3\text{H}_2\text{O} = 6 \times \text{Mass of H} + 3 \times \text{Mass of O} = 6 \times 1 + 3 \times 16 \] \[ = 6 + 48 = 54 , \text{amu} \]
-
Total mass of the reactants: \[ \text{Total mass of reactants} = \text{Mass of }\text{FeCl}_3 + \text{Mass of }3\text{H}_2\text{O} = 161 + 54 = 215 , \text{amu} \]
Therefore, the total mass of the reactants is 215 amu.