A)
Use the chemical reaction to answer the question.
CaCO3→CO2+CaO
A scientist heats 30 grams of calcium carbonate (CaCO3
) in the chemical reaction shown. What is the total mass of the products?
(1 point)
Responses
15 grams
15 grams
10 grams
10 grams
60 grams
60 grams
30 grams
The total mass of the products can be found by adding the masses of the individual products. In this reaction, there is only one product, which is carbon dioxide (CO2) with a molar mass of 44.01 grams/mole. Therefore, the total mass of the products is equal to the molar mass of carbon dioxide, which is 44.01 grams.
So, the correct answer is 44 grams.
Use the chemical reaction to answer the question.
4Fe+3O2→2Fe2O3
What happens to atoms of Fe and O2 during the reaction?
(1 point)
Responses
They are lost.
They are lost.
They are rearranged.
They are rearranged.
They gain mass.
They gain mass.
They maintain their properties.
During the reaction, the atoms of Fe (iron) and O2 (oxygen) are rearranged to form Fe2O3 (iron oxide). Therefore, the correct answer is: They are rearranged.
Which is most likely to occur during a chemical reaction?(1 point)
Responses
Mass is conserved.
Mass is conserved.
Atoms of the original substance are lost.
Atoms of the original substance are lost.
New atoms are created.
New atoms are created.
The original substance maintains its properties.
The most likely occurrence during a chemical reaction is that mass is conserved. This means that the total mass of the reactants is equal to the total mass of the products. Therefore, the correct answer is: Mass is conserved.
Use the chemical reaction to answer the question.
NaHCO3+HC2H3O2→NaC2H3O2+H2O+CO2
A student mixes baking soda (NaHCO3
) and acetic acid (HC2H3O2
) to produce a chemical reaction shown. Which statement about the reaction is correct?
(1 point)
Responses
Some atoms gain mass after the reaction.
Some atoms gain mass after the reaction.
The atoms of the reactants are regrouped during the reaction.
The atoms of the reactants are regrouped during the reaction.
There are more H atoms after the reaction.
There are more H atoms after the reaction.
Atoms of Na are destroyed during the reaction.
Based on the given chemical reaction, the statement that is correct about the reaction is: The atoms of the reactants are regrouped during the reaction.
In this reaction, the atoms of the reactants (NaHCO3 and HC2H3O2) are rearranged to form the products (NaC2H3O2, H2O, and CO2). The reactant molecules are broken apart and their atoms are rearranged to form the product molecules. Therefore, the correct answer is: The atoms of the reactants are regrouped during the reaction.
Use the chemical reaction to answer the question.
2H2+O2→2H2O
There are four atoms of hydrogen (H
) before the reaction. How many atoms of hydrogen are present after the reaction?
(1 point)
Responses
8
8
4
4
2
2
5
In the chemical reaction given, 2H2 + O2 → 2H2O, there are a total of four atoms of hydrogen (H) present before the reaction.
After the reaction, the two molecules of H2 combine with one molecule of O2 to produce two molecules of H2O.
Each molecule of H2O contains two atoms of hydrogen.
Therefore, after the reaction, there would be a total of four atoms of hydrogen remaining, as each molecule of H2O contains two atoms of hydrogen.
So, the correct answer is: 4.
Use the chemical reaction to answer the question.
CaCO3→CO2+CaO
A scientist heats 30 grams of calcium carbonate (CaCO3
) in the chemical reaction shown. What is the total mass of the products?
(1 point)
Responses
15 grams
15 grams
10 grams
10 grams
60 grams
60 grams
30 grams