Question 1

Which law is the foundation of stoichiometry, ensuring that the total mass of reactants equals the total mass of products in a chemical reaction?

Accepted Answer

Law of Conservation of Mass

Question 2

Given the balanced equation $$4Fe(s) + 3O_2(g) \rightarrow 2Fe_2O_3(s)$$, what is the mole ratio of $$Fe to$$ $$O_2$$?

Accepted Answer

$$4:3$$

Question 3

A chemist wants to produce $$319.4\ g of$$ $$Fe_2O_3$$ using the reaction $$4Fe(s) + 3O_2(g) \rightarrow 2Fe_2O_3(s). $$How many grams of $$O_2$$ are required?

Accepted Answer

$$96.00\ g$$

Question 4

What does a mole ratio represent at the particle level in a balanced chemical equation?

Accepted Answer

The ratio of the number of particles (atoms, molecules, or formula units) of each substance

Question 5

If $$8\ mol of$$ $$Fe$$ react with excess $$O_2$$ according to $$4Fe(s) + 3O_2(g) \rightarrow 2Fe_2O_3(s)$$, how many moles of $$Fe_2O_3$$ are produced?

Accepted Answer

$$4\ mol$$

Question 6

Which of the following best describes the process of converting grams of a reactant to grams of a product in a chemical reaction?

Accepted Answer

Grams of A $$\rightarrow$$ Moles of A $$\rightarrow$$ Moles of B $$\rightarrow$$ Grams of B

Question 7

A pharmaceutical company needs to produce $$0.50\ mol of$$ $$Fe_2O_3$$ for a medication. How many moles of $$O_2$$ are required according to $$4Fe(s) + 3O_2(g) \rightarrow 2Fe_2O_3(s)$$?

Accepted Answer

$$0.75\ mol$$

Question 8

Why is it important for chemists to use stoichiometry in pollution control?

Accepted Answer

To calculate the exact amounts of reactants needed to neutralize pollutants

Question 9

If $$223.4\ g of$$ $$Fe$$ completely reacts with $$96.00\ g of$$ $$O_2$$, what is the total mass of products formed?

Accepted Answer

$$319.4\ g$$

Question 10

Which of the following is NOT a correct mole ratio for the reaction $$4Fe(s) + 3O_2(g) \rightarrow 2Fe_2O_3(s)$$?

Accepted Answer

$$3\ mol\ Fe : 4\ mol\ O_2$

Question 11

A student mixes $$6.0\ mol of$$ $$Fe$$ with $$6.0\ mol of$$ $$O_2 in $$the reaction $$4Fe(s) + 3O_2(g) \rightarrow 2Fe_2O_3(s). $$Which reactant is the limiting reagent?

Accepted Answer

$$Fe$$

Question 12

How many different mole ratios can be written for the reaction $$4Fe(s) + 3O_2(g) \rightarrow 2Fe_2O_3(s)$$?

Accepted Answer

$$6$$

Question 13

Which step is necessary to connect the microscopic world of particles to the macroscopic world of laboratory measurements in stoichiometry?

Accepted Answer

Using Avogadro's number to convert between moles and particles

Question 14

In a real-world scenario, why might a chemist need to calculate the limiting reactant in a reaction?

Accepted Answer

To predict the maximum amount of product that can be formed

Question 15

A factory uses the reaction $$4Fe(s) + 3O_2(g) \rightarrow 2Fe_2O_3(s) to $$produce iron(III) oxide. If the factory starts with $$500\ g of$$ $$Fe$$ and excess $$O_2$$, how many grams of $$Fe_2O_3$$ can be produced? ($$M_{Fe} = 55.85\ g/mol$$, $$M_{Fe_2O_3} = 159.7\ g/mol)$$

Accepted Answer

$$713.8\ g$$

Question 16

Which of the following best explains why stoichiometry is essential in pharmaceutical dosing?

Accepted Answer

It allows precise calculation of reactants to produce the exact amount of active ingredient

Question 17

If $$2.0\ mol of$$ $$O_2$$ are available, what is the maximum number of moles of $$Fe_2O_3$$ that can be formed according to $$4Fe(s) + 3O_2(g) \rightarrow 2Fe_2O_3(s)$$?

Accepted Answer

$$1.33\ mol$$

Question 18

Which of the following is a real-life application of stoichiometry?

Accepted Answer

Calculating the amount of fertilizer needed for crops

Question 19

A reaction stops when one reactant is used up. What is this reactant called?

Accepted Answer

Limiting reactant

Reaction Stoichiometry: Quantitative Relationships in Chemical Reactions

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