In which chemical equation is the number of atoms in the reactants the same as the number of atoms in the products?(1 point)
Responses
Zn + 2HCl → H2 + ZnCl2
Zn + 2HCl → H 2 + ZnCl 2
CO2 + H2O → CH2OH + O2
CO 2 + H 2 O → CH 2 OH + O 2
Li2CO3 → LiO + CO2
Li 2 CO 3 → LiO + CO 2
CH4 + O2 → CO2 + 2H2O
CH 4 + O 2 → CO 2 + 2H 2 O
Which statement is true regarding a chemical reaction?(1 point)
Responses
The total number of atoms does not change, so mass is conserved in the reaction.
The total number of atoms does not change, so mass is conserved in the reaction.
Even if the total number of atoms changes, mass may not be conserved in the reaction.
Even if the total number of atoms changes, mass may not be conserved in the reaction.
The total number of atoms changes, so mass is conserved in the reaction.
The total number of atoms changes, so mass is conserved in the reaction.
Even if the total number of atoms does not change, mass may not be conserved in the reaction.
Even if the total number of atoms does not change, mass may not be conserved in the reaction.
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The total number of atoms does not change, so mass is conserved in the reaction.
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
161 amu
161 amu
108 amu
108 amu
179 amu
179 amu
215 amu
215 amu
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To find the total mass of the reactants, we need to calculate the mass of FeCl3 and the mass of 3H2O and then add them together.
The molar mass of FeCl3 can be calculated as follows:
Fe: 1 atom x 56 amu/atom = 56 amu
Cl: 3 atoms x 35 amu/atom = 105 amu
Total mass of FeCl3 = 56 amu + 105 amu = 161 amu
The molar mass of H2O can be calculated as follows:
H: 2 atoms x 1 amu/atom = 2 amu
O: 1 atom x 16 amu/atom = 16 amu
Total mass of H2O = 2 amu + 16 amu = 18 amu
Thus, the total mass of the reactants is 161 amu + 18 amu = 179 amu.
Therefore, the correct answer is: 179 amu.
4 of 44 of 4 Items
Question
In a chemical reaction, two molecules with a total mass of 76 amu react to form a single molecule. What is the mass of the molecule that is formed?(1 point)
Responses
228 amu
228 amu
38 amu
38 amu
76 amu
76 amu
152 amu