Conservation in Chemical Reactions Quick Check
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)
A.) 161 amu
B.) 179 amu
C.) 108 amu
D.) 215 amu
The answer is actually 215 amu so D
To find the total mass of the reactants, we need to calculate the sum of the masses of each atom present in the reactants:
FeCl3 + 3H2O
For FeCl3:
Mass of Fe = 56 amu
Mass of Cl (3 atoms) = 35 amu x 3 = 105 amu
Total mass for FeCl3 = 56 amu + 105 amu = 161 amu
For 3H2O:
Mass of H (6 atoms) = 1 amu x 6 = 6 amu
Mass of O (3 atoms) = 16 amu x 3 = 48 amu
Total mass for 3H2O = 6 amu + 48 amu = 54 amu
Summing the total masses of FeCl3 and 3H2O:
161 amu + 54 amu = 215 amu
Therefore, the total mass of the reactants is 215 amu.
The correct answer is:
D.) 215 amu