Conservation in Chemical Reactions Quick Check

Question

Science 8 Q1 / Matter Interactions

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

161 amu

179 amu

215 amu

Answer 1

To find the total mass of the reactants, we need to add up the atomic masses of each element in the reactants FeCl3 and H2O.

FeCl3:
Fe (Atomic mass = 56 amu) + Cl3 (Atomic mass of one Cl atom = 35 amu) = 56 amu + 3 * 35 amu = 56 amu + 105 amu = 161 amu

H2O:
H2 (Atomic mass of one H atom = 1 amu) + O (Atomic mass = 16 amu) = 2 * 1 amu + 16 amu = 2 amu + 16 amu = 18 amu

Total mass of the reactants = Mass of FeCl3 + Mass of H2O = 161 amu + 18 amu = 179 amu

Therefore, the correct answer is 179 amu.