Question

FeCl3+3H2O->Fe(OH)3+3HCl

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?

108 amu
179 amu
215 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 determine the masses of each component in the reactants.

1. Calculate the mass of \( \text{FeCl}_3 \):
- The mass of \( \text{Fe} \) is 56 amu.
- The mass of \( \text{Cl} \) is 35 amu, and there are 3 chlorine atoms in \( \text{FeCl}_3 \).
- Therefore, the mass contribution from chlorine is \( 3 \times 35 = 105 \) amu.
- Total mass of \( \text{FeCl}_3 \) is:
\[
56 \, \text{amu (Fe)} + 105 \, \text{amu (Cl)} = 161 \, \text{amu}
\]

2. Calculate the mass of \( 3\text{H}_2\text{O} \):
- The mass of \( \text{H}_2\text{O} \) is calculated as:
- The mass of \( \text{H} \) is 1 amu, and there are 2 hydrogen atoms, so contribution from hydrogen is \( 2 \times 1 = 2 \) amu.
- The mass of \( \text{O} \) is 16 amu.
- Total mass of \( \text{H}_2\text{O} \) is:
\[
2 \, \text{amu (H)} + 16 \, \text{amu (O)} = 18 \, \text{amu}
\]
- Since there are 3 water molecules, the total mass from water is:
\[
3 \times 18 \, \text{amu} = 54 \, \text{amu}
\]

3. Now, add the masses of the reactants together:
- Total mass of the reactants is:
\[
161 \, \text{amu (from FeCl}_3\text{)} + 54 \, \text{amu (from 3H}_2\text{O)} = 215 \, \text{amu}
\]

The total mass of the reactants is **215 amu**.