Use the equation and the table to answer the question.

Question

FeCl3 + 3H2O -- Fe(OH)3 + 3HCl
Element
Fe
Cl
H
O
Mass of an Atom (amu)
(Fe) 56
(Cl) 35
(H) 1
(O) 16
Iron chloride and water react according to the equation shown. The table shows the atomic masses of the elements involved in the reaction. What is the total mass of the reactants?
A. 215 amu
B. 108 amu
C. 179 amu
D. 161 amu

Answer 1

To calculate the total mass of the reactants in the equation:

\[ \text{FeCl}_3 + 3\text{H}_2\text{O} \]

we first need to determine the mass of each reactant based on the provided atomic masses.

1. Calculate the mass of FeCl3:

   • Iron (Fe) = 1 x 56 amu = 56 amu
   • Chlorine (Cl) = 3 x 35 amu = 105 amu
   • Total mass of FeCl3 = 56 amu + 105 amu = 161 amu

2. Calculate the mass of 3 H2O:

   • Hydrogen (H) = 2 x 1 amu = 2 amu per water molecule
   • Oxygen (O) = 1 x 16 amu = 16 amu per water molecule
   • Total mass of one H2O molecule = 2 amu + 16 amu = 18 amu
   • For 3 H2O: 3 x 18 amu = 54 amu

3. Total mass of reactants:

   • Total mass of reactants = mass of FeCl3 + mass of 3H2O
   • Total mass of reactants = 161 amu + 54 amu = 215 amu

Thus, the total mass of the reactants is 215 amu.

The correct answer is A. 215 amu.