Question

Use the equation and the table to answer the question.

FeCl3 + 3H2O → Fe(OH)3 + 3HCl

Atomic Masses of Elements
Element 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?

(1 point)
Responses

179 amu
179 amu

215 amu
215 amu

108 amu
108 amu

161 amu

Answer 1

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

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

we need to sum the atomic masses of all the atoms in the reactants.

1. **Calculate the mass of FeCl3:**

- Iron (Fe): 1 atom × 56 amu = 56 amu
- Chlorine (Cl): 3 atoms × 35 amu = 3 × 35 = 105 amu

Total mass of FeCl3 = 56 amu + 105 amu = **161 amu**

2. **Calculate the mass of 3H2O:**

- Hydrogen (H): 2 atoms per water molecule × 3 molecules = 6 atoms × 1 amu = 6 amu
- Oxygen (O): 1 atom per water molecule × 3 molecules = 3 atoms × 16 amu = 48 amu

Total mass of 3H2O = 6 amu + 48 amu = **54 amu**

3. **Calculate the total mass of reactants (FeCl3 + 3H2O):**

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

The total mass of the reactants is **215 amu**. Therefore, the correct response is:

**215 amu**