Exothermic and endothermic reactions

• Chemistry
• Secondary Education
• Age 12,13

Exothermic and Endothermic Reactions

Topic 6. Chemical Energetics 

28 February 2024

Our Learning Map

prepare a quick slide presentation about the chosen scenario that demonstrates the difference between exothermic or endothermic reactions

exemplify the importance of exothermic and endothermic reactions in daily life

prepare a quick slide presentation to show an interpretation of an exothermic or an endothermic reaction profile (reaction pathway diagram)

Flipped learning Review

• Goal - Pair up and answer the given questions in the Kahoot game. The questions are based on the video content. Win the game, and you earn an EC.
• Product/Output - Kahoot results.
• Standards - Correct responses.

kahoot.it

Hinge-point Discussion

reactants

product

carbon + 2 oxygen

carbon dioxide

Types of Chemical Processes

Correcting Misconception

ALL chemical reactions are exothermic.

Correcting Misconception

ALL chemical reactions are exothermic.

Types of Chemical Reactions

Exothermic and Endothermic Reactions

Topic 6. Chemical Energetics 

28 February 2024

Reaction Pathway Diagrams (Reaction Profiles)

• Used to represent the energy changes involved in a chemical reaction

Step 1 : Draw and label the x and y axes.

Step 2 : Write the chemical equation.

Step 3 : Identify whether it is an exothermic or endothermic reaction.

Step 4 : Draw the line for the reactant.

Step 5 : Draw the line for the product.

Step 6 : Draw the arrow for the energy released or absorbed.

Example 1:

STEPS:

Step 1 : Draw and label the x and y axes.<div>Step 2 : Write the chemical equation.</div><div>Step 3 : Identify whether it is an exothermic or endothermic reaction.</div><div>Step 4 : Draw the line for the reactant.</div><div>Step 5 : Draw the line for the product.</div><div>Step 6 : Draw the arrow for the energy released or absorbed.</div>

CH₄ (g) + O₂ (g) → CO₂ (g) + 2H₂O (l)          △H = - 891 kJ/mol

Example 2:

STEPS:

Step 1 : Draw and label the x and y axes.<div>Step 2 : Write the chemical equation.</div><div>Step 3 : Identify whether it is an exothermic or endothermic reaction.</div><div>Step 4 : Draw the line for the reactant.</div><div>Step 5 : Draw the line for the product.</div><div>Step 6 : Draw the arrow for the energy released or absorbed.</div>

CaCO₃ (s) →  CaO (s) + CO₂ (g)          △H = +178 kJ/mol

heat

Exothermic and Endothermic Reactions

Topic 6. Chemical Energetics 

28 February 2024

Closing : Lesson Key Points