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
Li2CO3 → LiO + CO2
Li 2 CO 3 → LiO + CO 2
CH4 + O2 → CO2 + 2H2O
CH 4 + O 2 → CO 2 + 2H 2 O
CO2 + H2O → CH2OH + O2
The chemical equation in which the number of atoms in the reactants is the same as the number of atoms in the products is:
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 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.
Even if the total number of atoms changes, mass may not be conserved in the reaction.
The correct statement regarding a chemical reaction is:
The total number of atoms does not change, so mass is conserved in the reaction.
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
179 amu
179 amu
215 amu
215 amu
108 amu
108 amu
To determine the total mass of the reactants, we need to find the sum of the atomic masses of all the elements involved.
The chemical equation is not provided, so we cannot directly calculate the total mass of the reactants.
Please provide the chemical equation so that we can determine the total mass of the reactants.
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)
Responses
To find the total mass of the reactants, we need to calculate the sum of the atomic masses of each element in the reactants.
FeCl3: Fe (1 atom) + Cl (3 atoms) = (56 amu) + (35 amu x 3) = 56 amu + 105 amu = 161 amu
H2O: H (2 atoms) + O (1 atom) = (1 amu x 2) + 16 amu = 2 amu + 16 amu = 18 amu
Adding the masses of FeCl3 and H2O:
161 amu + 18 amu = 179 amu
Therefore, the total mass of the reactants is 179 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
228 amu
228 amu
76 amu
76 amu
38 amu
38 amu
152 amu
To find the mass of the molecule that is formed, we need to subtract the mass of the two molecules that are reacting from the total mass.
Total mass of the reactants: 76 amu
Mass of the molecule formed: Total mass of reactants - mass of two reactant molecules
Mass of the molecule formed: 76 amu - (mass of one reactant molecule + mass of one reactant molecule)
Since two molecules with a total mass of 76 amu react to form a single molecule, the mass of the molecule formed is 76 amu. Therefore, the correct answer is:
76 amu