To find the total mass of the reactants, we need to calculate the mass of each element in the reactants and then add them together.
FeCl3:
Fe = 56 amu
Cl = 3 x 35 amu = 105 amu
Total mass of FeCl3 = 56 amu + 105 amu = 161 amu
H2O:
H = 2 x 1 amu = 2 amu
O = 16 amu
Total mass of H2O = 2 amu + 16 amu = 18 amu
Since there are 3 moles of H2O in the reaction, total mass of H2O = 3 x 18 amu = 54 amu
Total mass of the reactants = Total mass of FeCl3 + Total mass of H2O
= 161 amu + 54 amu
= 215 amu
Therefore, the total mass of the reactants is 215 amu.
So, the correct answer is:
C. 215 amu