Limiting Reactants Notes

Multiple Choice

What is a limiting reactant?

• A reactant that runs out, stopping the reaction from continuing.

• A reactant that remains after the reaction has stopped.

• A reactant that has the least mass.

• A reactant that has the most mass.

Multiple Choice

What is an excess reactant?

• A reactant that runs out, stopping the reaction from continuing.

• A reactant that still remains after the reaction has stopped.

• A reactant that has the least mass.

• A reactant that has the most mass.

Multiple Choice

How do you determine if the problem has a limiting reactant?

• There is information about the mass or the moles of two or more reactants.

• There are more than one reactant in the reaction.

• There are more than one product in the reactions.

• All stoichiometry problems are limiting reactant problems.

Multiple Choice

Identify if the problem will be a limiting reactant problem:

How many moles of ammonia are formed when 2.00 moles of nitrogen reacts with hydrogen?

• It is a limiting reactant problem because the moles of a reactant is given.

• It is NOT a limiting reactant problem because the moles of one reactant is given.

• It is NOT a limiting reactant problem because the products are given for the reaction.

• It is a limiting reactant problem because the moles of two reactants are given.

Multiple Choice

Identify if the problem will be a limiting reactant problem:

How many moles of sodium chloride is formed when 45.8 g NaOH reacts with 26.5 moles HCl?

• It is a limiting reactant problem because the quantitative values of a reactant is given.

• It is NOT a limiting reactant problem because the quantitative values of one reactant is given.

• It is NOT a limiting reactant problem because the products are given for the reaction.

• It is a limiting reactant problem because the

  quantitative values of two reactants are given.

Multiple Choice

Identify if the problem will be a limiting reactant problem:

How many grams of iron is needed to react with 97.26 grams of oxygen to form iron(III) oxide?

• It is a limiting reactant problem because the quantitative values of a reactant is given.

• It is NOT a limiting reactant problem because the quantitative values of one reactant is given.

• It is NOT a limiting reactant problem because the products are given for the reaction.

• It is a limiting reactant problem because the quantitative values of two reactants are given.

Multiple Choice

Identify if the problem will be a limiting reactant problem:

A reaction occurs between a 112.9 grams of cobalt and oxygen. If the reaction starts with 7.2 moles of oxygen, how many grams of cobalt(III) oxide can be formed?

• It is a limiting reactant problem because the quantitative values of a reactant is given.

• It is NOT a limiting reactant problem because the quantitative values of one reactant is given.

• It is NOT a limiting reactant problem because the products are given for the reaction.

• It is a limiting reactant problem because the quantitative values of two reactants are given.

Multiple Choice

Identify if the problem will be a limiting reactant problem:

How many moles of sodium chloride is formed when 45.8 g NaOH reacts with 26.5 moles HCl?

• It is a limiting reactant problem.

• It is NOT a limiting reactant problem.

Reorder

Place the steps in order for solving a limiting reactant stoichiometry problem.

• Write a balanced chemical equation.

• Write your find and given.

• Determine which reactant is the limiting reactant.

• Setup the problem using the limiting reactant.

• Solve the problem using correct significant figures.

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

Reorder

Place the steps in order for determining the limiting reactant according to these notes.

• Calculate the moles for each reactant.

• Divide moles of each reactant by its coefficient.

• Identify which reactant has the smaller number of moles.

1

2

3

• 1
• 2
• 3

Labelling

2 H₂(g) + O₂(g) → 2 H₂O(l)

A reaction occurs between 5.0 moles of hydrogen and 3.0 moles of oxygen to form water. How many moles of water are formed?

Label the following setup to solve the problem.

Drag labels to their correct position on the image

1 mol O2

1

2 mol H₂O

5.0 mol H₂

2.02 g/mol

3.0 mol O₂

2.02 g H₂

2 mol H₂

1 mol H₂

32.00 g/mol

Math Response

When a reaction occurs between 5.0 moles of hydrogen and 3.0 moles of oxygen, it forms _______ moles of water.

Type answer here

Correct Answer: 5.0

Deg^°

Rad

Complete the following practice problem in your notes using dimensional analysis. Then answer the questions that follow.

The balanced reaction for the combustion of ethane is shown below:

2 C₂H₆(g)+ 7 O₂(g) → 6 H₂O(g) + 4 CO₂(g)

1.45 g C₂H₆ was burned in the presence of 4.50 g O₂. How many moles of carbon dioxide is formed?

​Practice Problem

Multiple Choice

Which of the following is the limited reactant?

• ethane

• oxygen

• carbon dioxide

• water

Labelling

Label the following set as need to solve the problem:

2 C₂H₆(g)+ 7 O₂(g) → 6 H₂O(g) + 4 CO₂(g)

1.45 g C₂H₆ was burned in the presence of 4.50 g O₂. How many moles of carbon dioxide is formed?

Drag labels to their correct position on the image

1 mol C₂H₆

32.00 g O₂

1.45 g C₂H₆

1

4 mol CO2

7 mol O₂

2 mol C₂H₆

30.08 g C₂H₆

1 mol O₂

4.50 g O₂

Math Response

2 C₂H₆(g)+ 7 O₂(g) → 6 H₂O(g) + 4 CO₂(g)

A 1.45 g sample of C₂H₆ was burned in the presence of 4.50 g O₂ forming ____ mol CO₂.

Type answer here

Correct Answer: 0.0804

Deg^°

Rad