To find the total mass of the reactants, we need to add up the atomic masses of each element in the reactants FeCl3 and H2O.
FeCl3:
Fe (Atomic mass = 56 amu) + Cl3 (Atomic mass of one Cl atom = 35 amu) = 56 amu + 3 * 35 amu = 56 amu + 105 amu = 161 amu
H2O:
H2 (Atomic mass of one H atom = 1 amu) + O (Atomic mass = 16 amu) = 2 * 1 amu + 16 amu = 2 amu + 16 amu = 18 amu
Total mass of the reactants = Mass of FeCl3 + Mass of H2O = 161 amu + 18 amu = 179 amu
Therefore, the correct answer is 179 amu.