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
Li2CO3 → LiO + CO2
Li 2 CO 3 → LiO + CO 2
Zn + 2HCl → H2 + ZnCl2
Zn + 2HCl → H 2 + ZnCl 2
CH4 + O2 → CO2 + 2H2O
CH 4 + O 2 → CO 2 + 2H 2 O
CO2 + H2O → CH2OH + O2
CH4 + O2 → CO2 + 2H2O
Which statement is true regarding a chemical reaction?(1 point)
Responses
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.
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.
Even if the total number of atoms does not change, mass may not be conserved in the reaction.
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
215 amu
215 amu
108 amu
108 amu
179 amu
179 amu
161 amu
161 amu
To find the total mass of the reactants, we need to calculate the total mass of each individual reactant and then add them together.
FeCl3:
Fe: 1 atom (56 amu)
Cl: 3 atoms (35 amu each) = 105 amu
Total mass of FeCl3 = 56 amu + 105 amu = 161 amu
H2O:
H: 6 atoms (1 amu each) = 6 amu
O: 3 atoms (16 amu each) = 48 amu
Total mass of H2O = 6 amu + 48 amu = 54 amu
Total mass of the reactants = 161 amu (FeCl3) + 54 amu (H2O) = 215 amu
Therefore, the total mass of the reactants is 215 amu.
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
152 amu
152 amu
76 amu
76 amu
38 amu
38 amu
228 amu
To find the mass of the molecule that is formed, we need to divide the total mass of the reactants by the number of molecules that are formed.
Total mass of the reactants = 76 amu
Since two molecules react to form a single molecule, we divide the total mass of the reactants by 2:
76 amu / 2 = 38 amu
Therefore, the mass of the molecule that is formed is 38 amu.