Conservation in Chemical Reactions Quick Check

Question

3 of 43 of 4 Items
Question
Use the equation and the table to answer the 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?

(1 point)
Responses

108 amu
108 amu

215 amu
215 amu

179 amu
179 amu

161 amu
161 amu
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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 find the mass of all the elements in the reactants individually.

1. FeCl₃:

   • Mass of Fe = 56 amu
   • Mass of Cl = 35 amu (and there are 3 Cl atoms in FeCl₃)

   \[ \text{Total mass of FeCl}_3 = 56 + (3 \times 35) = 56 + 105 = 161 \text{ amu} \]

2. 3H₂O:

   • Mass of H = 1 amu (and there are 2 H atoms in each water molecule, so for 3 water molecules we have 6 H atoms)
   • Mass of O = 16 amu (and there is 1 O atom in each water molecule, so for 3 water molecules we have 3 O atoms)

   \[ \text{Total mass of } 3\text{H}_2\text{O} = (3 \times 2 \times 1) + (3 \times 16) = 6 + 48 = 54 \text{ amu} \]

Now, add the total mass of the reactants together:

\[ \text{Total mass of reactants} = \text{Total mass of FeCl}_3 + \text{Total mass of } 3\text{H}_2\text{O} = 161 + 54 = 215 \text{ amu} \]

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