To find the total mass of the reactants in the reaction \( \text{FeCl}_3 + 3 \text{H}_2\text{O} \), we need to calculate the mass of each reactant based on their respective formulas and atomic masses.
-
FeCl3 (Iron(III) chloride):
- 1 Fe atom: \( 56 , \text{amu} \)
- 3 Cl atoms: \( 3 \times 35 , \text{amu} = 105 , \text{amu} \)
Total mass of FeCl3: \[ 56 , \text{amu} + 105 , \text{amu} = 161 , \text{amu} \]
-
H2O (Water):
- 2 H atoms: \( 2 \times 1 , \text{amu} = 2 , \text{amu} \)
- 1 O atom: \( 16 , \text{amu} \)
Total mass of 3 H2O (since there are 3 water molecules): \[ 3 \times (2 , \text{amu} + 16 , \text{amu}) = 3 \times 18 , \text{amu} = 54 , \text{amu} \]
-
Total mass of the reactants: \[ \text{Total mass} = \text{mass of FeCl}_3 + \text{mass of 3 H}_2\text{O} = 161 , \text{amu} + 54 , \text{amu} = 215 , \text{amu} \]
Therefore, the total mass of the reactants is 215 amu.