Chemical Reactions Quick Check
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Question
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
10 grams
10 grams
60 grams
60 grams
15 grams
15 grams
30 grams
To find the total mass of the products, we need to determine the molar mass of each product and then calculate the mass based on the stoichiometry of the reaction.
The molar mass of CO2 is 44 grams/mol and the molar mass of CaO is 56 grams/mol.
Since the stoichiometric coefficient for CO2 is 1, the mass of CO2 produced is 1 * (44 grams/mol) = 44 grams.
Similarly, since the stoichiometric coefficient for CaO is also 1, the mass of CaO produced is 1 * (56 grams/mol) = 56 grams.
Adding the masses of CO2 and CaO gives us the total mass of the products: 44 grams + 56 grams = 100 grams.
Therefore, the correct answer is 100 grams.
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?
a 10 grams
b 60 grams
c 15 grams
d 30 grams
To find the total mass of the products, we need to determine the molar masses of CO2 and CaO and then use stoichiometry to calculate the mass of each product.
The molar mass of CO2 is 44 g/mol and the molar mass of CaO is 56 g/mol.
From the balanced equation, we can see that for every 1 mole of CaCO3, 1 mole of CO2 and 1 mole of CaO are produced.
Since we are given 30 grams of CaCO3, we need to calculate the moles of CaCO3 first.
moles of CaCO3 = mass of CaCO3 / molar mass of CaCO3
moles of CaCO3 = 30 g / 100.09 g/mol (molar mass of CaCO3)
moles of CaCO3 ≈ 0.2999 mol
Based on the stoichiometry, we can see that 1 mole of CaCO3 produces 1 mole of CO2 and 1 mole of CaO, which means the moles of CO2 and CaO produced will also be approximately 0.2999 mol.
To calculate the mass of CO2 and CaO produced, we can use the following equations:
mass of CO2 = moles of CO2 * molar mass of CO2
mass of CO2 = 0.2999 mol * 44 g/mol
mass of CO2 ≈ 13.196 g ≈ 13.2 g (rounded to the nearest tenth)
mass of CaO = moles of CaO * molar mass of CaO
mass of CaO = 0.2999 mol * 56 g/mol
mass of CaO ≈ 16.792 g ≈ 16.8 g (rounded to the nearest tenth)
Therefore, the total mass of the products (CO2 + CaO) is approximately 13.2 g + 16.8 g = 30 g.
The correct answer is d) 30 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 rearranged.
They are rearranged.
They gain mass.
They gain mass.
They maintain their properties.
They maintain their properties.
They are lost.
The correct answer is: They are rearranged.
During a chemical reaction, atoms are rearranged to form new compounds. In the given reaction, 4 atoms of iron (Fe) react with 3 molecules of oxygen (O2) to form 2 molecules of iron oxide (Fe2O3). The iron and oxygen atoms are not lost or gained, but rather rearranged to form a new compound. Therefore, the atoms maintain their properties but are rearranged in the reaction.
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.
The original substance maintains its properties.
The original substance maintains its properties.
New atoms are created.
To find the total mass of the products in the chemical reaction, we need to use the balanced equation and the molar masses of the substances involved.
The balanced equation given is:
CaCO3 → CO2 + CaO
To find the total mass of the products, we first need to calculate the molar masses of CO2 and CaO.
The molar mass of CO2 (carbon dioxide) is found by adding up the atomic masses of carbon (C) and oxygen (O):
C: 12.01 g/mol
O: 16.00 g/mol (there are two oxygen atoms in CO2)
Molar mass of carbon dioxide (CO2):
12.01 g/mol + 16.00 g/mol + 16.00 g/mol = 44.01 g/mol
The molar mass of CaO (calcium oxide) is found by adding up the atomic masses of calcium (Ca) and oxygen (O):
Ca: 40.08 g/mol
O: 16.00 g/mol (there is one oxygen atom in CaO)
Molar mass of calcium oxide (CaO):
40.08 g/mol + 16.00 g/mol = 56.08 g/mol
Now, we can calculate the total mass of the products using the molar masses and stoichiometry:
The molar ratio between CaCO3 and CO2 in the balanced equation is 1:1. Therefore, the molar mass of CO2 is equal to the molar mass of CaCO3.
Given that the mass of CaCO3 is 30 grams, the mass of CO2 produced will also be 30 grams.
Next, we can determine the mass of CaO produced. The molar ratio between CaCO3 and CaO is 1:1. This means that 1 mole of CaCO3 produces 1 mole of CaO.
The molar mass of CaCO3 is 100.09 g/mol (40.08 g/mol for Ca + 12.01 g/mol for C + 3(16.00 g/mol) for O).
Using the molar mass and the given mass of CaCO3 (30 grams), we can determine the number of moles of CaCO3:
30 g / 100.09 g/mol = 0.2999 mol (approximately)
Since the molar ratio is 1:1 between CaCO3 and CaO, the mass of CaO produced will also be approximately 30 grams (0.2999 mol × 56.08 g/mol).
Therefore, the total mass of the products in the chemical reaction is approximately 30 grams of CO2 and 30 grams of CaO.
The correct response is "30 grams".