Heats of Formation Breakout - AP Chem

Haunted Chem

START

escape game

Introduction

Mission

Suspects

Introduction

Mission

Suspects

"One of the teachers at Lone Star is a vampire. Solve the uestions over heats of formation to see which teacher is in fact....cold"

x

Introduction

Mission

Suspects

Enthalpies of formation, ΔH°f , are commonly tabulated in chemistry texts and reference materials. They are the most common way of calculating theoretical ΔH° values via Hess’s law, but often the reaction that they refer to is not shown in the table. In this activity, we will explore these values, what they represent and how they can be used to predict the enthalpies of other reactions.

x

Introduction

Mission

Characters

x

Mrs. Fitzpatrick

Mrs. McDonald

Mr. Dykema

Mrs. Ray

Science

History

Math

ELA

Who

is

it?

1 Find the key to enter

2 Welcome

Is closed...

Q1 Search for clues

Question 1

Question 1 Consider the reactions in Model 1. What type of reaction are all of the examples in Model 1— synthesis, decomposition, single replacement, double replacement or combustion?

Click here for Model 1

Click the piano to Answer

combustion

double replacement

single replacement

decomposition

4 Touch the correct key

synthesis

Q2 Search for clues

Question 2

Question 1 Compare the first reaction in each set (producing aluminum oxide). Which of the following notes how the reactions are different? compounds, phases, reactants, products, coefficients

Click here for Model 1

Click the piano to answer

products

reactants

phases

coefficients

4 Touch the correct key

compounds

Q3 Search for clues

Question 3

Question 3 Heats of Formation Compare the two sets of reactions in Model 1 (search with the light for Model 1). Which set of reactions uses fractional coefficients to balance the equation, forcing the product to always have a coefficient of one?

Click here for Model 1

Click the piano to solve

Both

None

Set B

4 Touch the correct key

Set A

Q4 Search for clues

Question 4

Question 4 Heats of Formation Compare the two sets of reactions in Model 1 (search with the light for Model 1). Which set of reactions uses only elements as reactants?

Click here for Model 1

Click the piano to solve

Both

None

Set B

4 Touch the correct key

Set A

Q5 Search for clues

Question 5

Question 5 Heats of Formation Compare the two sets of reactions in Model 1 (search with the light for Model 1). Which set of reactions uses reactants that would not be stable substances (not in their natural state)? For example, a single oxygen atom is not a stable entity.

Click here for Model 1

Click the piano to solve

None

Both

Set B

4 Touch the correct key

Set A

Q6 Search for clues

Question 6

Question 6 Heats of Formation A formation reaction is defined as a synthesis reaction where one mole of product is made from component elements in their natural state. Which set of reactions in model 1 are formation reactions?

Click here for Model 1

Click the piano to solve

Both

Set B

4 Touch the correct key

Set A

None

STOPSolve the following problems and check in with your teacher. They'll give you the code to get out of this room.Explain why the following reactions are not formation reactions.

4 Touch the correct key

4 Touch the correct key

4 Touch the correct key

4 Touch the correct key

Level 2:Click the paper to see what is written.

Mr. Dykema is not the vampire you're looking for..

Introduction

Mission

Characters

x

Mrs. Fitzpatrick

Mrs. McDonald

Mr. Dykema

Mrs. Ray

Science

History

Math

ELA

Who

is

it?

Mr. Dykema has the Christmas Sprit. He is not our vampire. Let's find out who we can eliminate next.

Clint the spider, here. No one passes through this door until answering a question. Are standard heats of formation endothermic, exothermic, or both? Click the door to solve.

Are standard heats of formation endothermic, exothermic, or both?

Endothermic

Exothermic

Both

Correct! Drag the key to the lock and click.

Clint the spider, here. No one passes through this door until answering a question. Are standard heats of formation endothermic, exothermic, or both? Click the door to solve.

Your chemistry textbook probably has an appendix that tabulates standard heats of formation for many common substances. Rather than show the entire formation reaction, they simply list the compound that is formed. It is assumed that the user understands the reaction represented. Some of the values in the list are found by experiment, others are likely calculated indirectly from other data.

Read This!

+

-

In another tab, access the thermodynamic data in the textbook appendix.

Question: What is the ΔH°f for solid sodium chloride?

+

-

In another tab, access the thermodynamic data in the textbook appendix.

Question: What is the ΔH°f for solid sodium chloride?

+

-

In another tab, access the thermodynamic data in the textbook appendix.

Question: What is the ΔH°f for solid sodium chloride?

1

+

-

In another tab, access the thermodynamic data in the textbook appendix.

Question: What is the ΔH°f for solid sodium chloride?

1

+

-

In another tab, access the thermodynamic data in the textbook appendix.

Write the reaction that involves that energy change.Check in with your teacher for the correct code to move on.

Something is wrong...

+

-

In another tab, access the thermodynamic data in the textbook appendix.

Question: What is the ΔH°f for gaseous iodine, I2 (g)?

+

-

In another tab, access the thermodynamic data in the textbook appendix.

Question: What is the ΔH°f for gaseous iodine, I2 (g)?

+

-

In another tab, access the thermodynamic data in the textbook appendix.

Question: What is the ΔH°f for gaseous iodine, I2 (g)?

+

-

In another tab, access the thermodynamic data in the textbook appendix.

Write the reaction that involves that energy change.Check in with your teacher for the correct code to move on.

+

-

In another tab, access the thermodynamic data in the textbook appendix.

Explain why the ΔH°f for gaseous oxygen, O2 (g), is zero.Check in with your teacher for the correct code to move on.

Something is wrong...

I can keep you warm but I’m not a scarf I’m often made of brick or stone but I’m not a wall I sometimes have a poker but I don’t have a deck of cards I contain logs but I’m not a forest

If a formation reaction was reversed, how could the standard enthalpy for that reaction be cal-culated from a standard heat of formation listed in the table? Illustrate your understanding by finding the ΔH° for the following reaction. HBr(g) → 1⁄2H2 (g) + 1⁄2Br2 (l)

Reversing the reaction reverses the sign

Reversing the reaction stays the same

If a formation reaction was multiplied by a factor, how could the standard enthalpy for that reaction be calculated from a Standard Heat of Formation listed in the table? Illustrate your understanding by finding the ΔH° for the following reaction. 2Al(s) + 3Cl2 (g) → 2AlCl3 (s)

Multiplying the reaction, multiplies the energy

Multiplying the reaction, divides the energy

Multiplying the reaction, causes the energy to stay the same

Level 3:Click the paper to see what is written.

Mrs. Fitzpatrick is not the vampire you're looking for..

Introduction

Mission

Characters

x

Mrs. Fitzpatrick

Mrs. McDonald

Mr. Dykema

Mrs. Ray

Science

History

Math

ELA

Who

is

it?

Mrs. Fitz also has the Christmas Sprit. She is not our vampire. Let's find out who we can eliminate next.

Standard heats of formation can be used to predict the enthalpies of many other reactions. Imagine that a reaction occurs by all reactants decomposing into elements in their natural state and then recombining to form the products. Although very few chemical reactions occur in this manner, it does not really matter.Enthalpy is a state function, which means it is determined only by the initial state of the reaction and the final state of the reaction, not the process that occurs in between. The enthalpy change that is calculated for our imaginary process will give us the enthalpy for the real-life reaction. Therefore, several formation reactions (or reverse formation reactions) can be combined using Hess’s law to calculate the enthalpy for any reaction.

Read This!

Find the correct portal key to get your next question.

Write the reaction for the overall process in model 2. Answer by clicking each part on the model.

Click me to see Model 2

​​

Write the reaction for the overall process in model 2. Answer by clicking each part on the model.

Click me to see Model 2

​​

Write the reaction for the overall process in model 2. Answer by clicking each part on the model.

Click me to see Model 2

​​

Notice that the intermediates in the process in Model 2 are elements in their natural states. Which steps in the process in Model 2 represent formation reactions, or multiples of formation reactions?

Step 1

Steps 1 & 2

Steps 3 & 4

Step 4

Click me to see Model 2

​​

Click me to see Model 2

Notice that the intermediates in the process in Model 2 are elements in their natural states. Which steps in the process in Model 2 represent formation reactions, or multiples of formation reactions, in reverse?

Step 1

Step 2

Step 3

Step 4

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the reactants in Model 2 turn into the intermediates. Be sure to include the correct sign on this energy change.ΔHRXN = ___ kg/mol

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the reactants in Model 2 turn into the intermediates. Be sure to include the correct sign on this energy change.ΔHRXN = ___ kg/mol

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the reactants in Model 2 turn into the intermediates. Be sure to include the correct sign on this energy change.ΔHRXN = ___ kg/mol

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the intermediates in Model 2 turn into the products. Be sure to include the correct sign on this energy change.ΔHf=____ kj/mol

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the intermediates in Model 2 turn into the products. Be sure to include the correct sign on this energy change.ΔHf=____ kj/mol (Step 3)

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the intermediates in Model 2 turn into the products. Be sure to include the correct sign on this energy change.ΔHf=____ kj/mol (Step 3)

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the intermediates in Model 2 turn into the products. Be sure to include the correct sign on this energy change.ΔHf=____ kj/mol (Step 3)

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the intermediates in Model 2 turn into the products. Be sure to include the correct sign on this energy change.ΔHf=____ kj/mol (Step 3)

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the intermediates in Model 2 turn into the products. Be sure to include the correct sign on this energy change.ΔHf=____ kj/mol (Step 3)

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the intermediates in Model 2 turn into the products. Be sure to include the correct sign on this energy change.ΔHf=-242 KJ/mol (x2) = ____ KJ/mol (Step 4)

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the intermediates in Model 2 turn into the products. Be sure to include the correct sign on this energy change.ΔHf=-242 KJ/mol (x2) = ____ KJ/mol (step 4)

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the intermediates in Model 2 turn into the products. Be sure to include the correct sign on this energy change.ΔHf=-242 KJ/mol (x2) = ____ KJ/mol (Step 4)

Δ

+

-

​​

Click me to see Model 2

Use a table of standard heats of formation to calculate the energy change when the intermediates in Model 2 turn into the products. Be sure to include the correct sign on this energy change.ΔHf=-242 KJ/mol (x2) = ____ KJ/mol (step 4)

Δ

+

-

​​

Click me to see Model 2

Use your answers inthe previous two questions to calculate the overall ΔH° for the process in Model 2.___ KJ/mol

Δ

+

-

​​

No, try again.

Click me to see Model 2

Use your answers inthe previous two questions to calculate the overall ΔH° for the process in Model 2.___ KJ/mol

Δ

+

-

​​

Click me to see Model 2

Use your answers inthe previous two questions to calculate the overall ΔH° for the process in Model 2.___ KJ/mol

Δ

+

0

1

-

​​

Click me to see Model 2

Use your answers inthe previous two questions to calculate the overall ΔH° for the process in Model 2.___ KJ/mol

Δ

+

0

1

-

​​

Click me to see Model 2

Use your answers inthe previous two questions to calculate the overall ΔH° for the process in Model 2.___ KJ/mol

Δ

+

0

1

-

​​

Click me to see Model 2

Use your answers inthe previous two questions to calculate the overall ΔH° for the process in Model 2.___ KJ/mol

Δ

+

0

1

-

​​

Click me to see Model 2

Use what you have learned from Model 2 to calculate the standard enthalpy, ΔH°, for the following reaction using a table of standard heats of formation. Show all calculations and be prepared to explain your process for solving this problem.4NH3 (g) + 5O2 (g) → 4NO(g) + 6H2O(g)

+

-

​​

No, try again.

Click me to see Model 2

Use what you have learned from Model 2 to calculate the standard enthalpy, ΔH°, for the following reaction using a table of standard heats of formation. Show all calculations and be prepared to explain your process for solving this problem.4NH3 (g) + 5O2 (g) → 4NO(g) + 6H2O(g)

+

-

​​

Click me to see Model 2

Use what you have learned from Model 2 to calculate the standard enthalpy, ΔH°, for the following reaction using a table of standard heats of formation. Show all calculations and be prepared to explain your process for solving this problem.4NH3 (g) + 5O2 (g) → 4NO(g) + 6H2O(g)

+

-

0

1

​​

Click me to see Model 2

Use what you have learned from Model 2 to calculate the standard enthalpy, ΔH°, for the following reaction using a table of standard heats of formation. Show all calculations and be prepared to explain your process for solving this problem.4NH3 (g) + 5O2 (g) → 4NO(g) + 6H2O(g)

+

-

0

1

​​

Wrong

Go Back

Frank the frog here. You're almost finished. Click the right key portal to take you to your final TWO questions to see who the vampire is.

The heat of combustion for 1 mole of propane, C3H8, at standard conditions is −2,046 kJ.Write a balanced chemical equation for the combustion of propane to calculate the heat of formation, ΔH°f , of propane given that the ΔH°f of gaseous water is −242 kJ/mole and the ΔH°f of carbon dioxide gas is −394 kJ/mole.___ KJ/mol

The heat of combustion for 1 mole of propane, C3H8, at standard conditions is −2,046 kJ.Write a balanced chemical equation for the combustion of propane to calculate the heat of formation, ΔH°f , of propane given that the ΔH°f of gaseous water is −242 kJ/mole and the ΔH°f of carbon dioxide gas is −394 kJ/mole.___ KJ/mol

-

The heat of combustion for 1 mole of propane, C3H8, at standard conditions is −2,046 kJ.Write a balanced chemical equation for the combustion of propane to calculate the heat of formation, ΔH°f , of propane given that the ΔH°f of gaseous water is −242 kJ/mole and the ΔH°f of carbon dioxide gas is −394 kJ/mole.___ KJ/mol

-1

The heat of combustion for 1 mole of propane, C3H8, at standard conditions is −2,046 kJ.Write a balanced chemical equation for the combustion of propane to calculate the heat of formation, ΔH°f , of propane given that the ΔH°f of gaseous water is −242 kJ/mole and the ΔH°f of carbon dioxide gas is −394 kJ/mole.___ KJ/mol

-10

Which of the two formation reactions below would you predict to have the largest exothermic heat of formation? Justify your reasoning.

See your teacher when you get the answer.

Mrs. Ray is NOT the vampire, which means...

Congratulations

It's your chemistry teacher!