Question 1

Question

A)How does stoichiometry support the law of conservation of mass?(1 point)
Responses

It compares the mass of each reactant to the mass of each product.
It compares the mass of each reactant to the mass of each product.

It compares the mass of the products to the mass of the reactants.
It compares the mass of the products to the mass of the reactants.

It compares the mass of the products to the number of atoms in the products.
It compares the mass of the products to the number of atoms in the products.

It compares the mass of the reactants to the number of moles of reactants.
It compares the mass of the reactants to the number of moles of reactants.
Question 2
A)
Nitrogen gas and hydrogen gas react to produce ammonia according to the following equation.

N2 + 3H2 → 2NH3

Which ratio of components is correct?

(1 point)
Responses

For every 2 moles of nitrogen gas, the reaction requires 3 moles of hydrogen gas.
For every 2 moles of nitrogen gas, the reaction requires 3 moles of hydrogen gas.

For every 3 moles of hydrogen gas, the reaction produces 2 moles of ammonia.
For every 3 moles of hydrogen gas, the reaction produces 2 moles of ammonia.

For every mole of hydrogen gas, the reaction produces 2 moles of ammonia.
For every mole of hydrogen gas, the reaction produces 2 moles of ammonia.

For every mole of nitrogen gas, the reaction produces 1 mole of ammonia.
For every mole of nitrogen gas, the reaction produces 1 mole of ammonia.
Question 3
A)
Nitrogen gas and hydrogen gas react to produce ammonia according to the following equation.

N2+3H2→2NH3

The atomic mass of nitrogen is 14 g/mol
. The atomic mass of hydrogen is 1 g/mol
. When the reaction produces 68
grams of ammonia, how many grams of nitrogen were present initially?

(1 point)
Responses

4
4

56
56

112
112

12
12
Question 4
A)
Use this chemical equation to answer the question.

A+2B→AB2

The molar mass of A
is 8 g/mol
. The molar mass of B
is 12 g/mol
. Which option shows the correct molar mass of AB2
?

(1 point)
Responses

20 g/mol
20 grams per mole

64 g/mol
64 grams per mole

40 g/mol
40 grams per mole

32 g/mol
32 grams per mole
Question 5
A)
Hydrogen and oxygen react to produce water according to the following equation.

2H2+O2→2H2O

The molar mass of hydrogen gas (H2
) is 2 g/mol
. The molar mass of oxygen gas (O2
) is 32 g/mol
. When the reaction starts with 64
grams of oxygen and a sufficient quantity of hydrogen, how many moles of water are produced?

(1 point)
Responses

18
18

8
8

2
2

4
4

Answer 1

Here are the answers to your questions based on the information provided:

Question 1: A) How does stoichiometry support the law of conservation of mass?
Correct Response: It compares the mass of each reactant to the mass of each product.

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Question 2: A) Nitrogen gas and hydrogen gas react to produce ammonia according to the given equation. Which ratio of components is correct?
Correct Response: For every 3 moles of hydrogen gas, the reaction produces 2 moles of ammonia.

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Question 3: A) When the reaction produces 68 grams of ammonia, how many grams of nitrogen were present initially?
To calculate this, first find how many moles of NH3 are produced:
Molar mass of NH3 = 14 (N) + 3(1) (H) = 17 g/mol.
Moles of NH3 produced = 68 g / 17 g/mol = 4 moles.
From the balanced equation, 2 moles of NH3 are produced from 1 mole of N2. Therefore, the amount of N2 required = 4 moles NH3 * (1 mole N2 / 2 moles NH3) = 2 moles N2.
Mass of N2 = 2 moles * 28 g/mol (for N2) = 56 grams.
Correct Response: 56

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Question 4: A) Given the molar mass of A is 8 g/mol and the molar mass of B is 12 g/mol, which option shows the correct molar mass of AB2?
Molar mass of AB2 = Molar mass of A + 2 * Molar mass of B = 8 + 2(12) = 8 + 24 = 32 g/mol.
Correct Response: 32 g/mol

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Question 5: A) When the reaction starts with 64 grams of oxygen and a sufficient quantity of hydrogen, how many moles of water are produced?
First, calculate moles of O2:
Moles of O2 = 64 g / 32 g/mol = 2 moles.
From the balanced equation, 1 mole of O2 produces 2 moles of H2O, so 2 moles of O2 will produce 4 moles of H2O.
Correct Response: 4

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