### Lesson Plan: Chemical Reactions - Part 3
#### Level: Senior Secondary 2
#### Subject: Chemistry
#### Duration: 90 minutes
#### Instructor: [Instructor's Name]
#### Date: [Insert Date]
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**Lesson Title:** Chemical Reactions - Part 3
**Objectives:**
- Understand the concept of reversible and irreversible reactions.
- Differentiate between endothermic and exothermic reactions.
- Identify and classify examples of chemical reactions based on reaction types.
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### **Materials Needed:**
- Whiteboard and markers
- Projector and laptop
- Handouts with reaction diagrams
- Lab equipment (test tubes, beakers, Bunsen burners, thermometers, etc.)
- Chemicals for demonstration (e.g., vinegar, baking soda, magnesium ribbon, hydrochloric acid)
- Safety goggles and gloves
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### **Lesson Structure:**
#### **Introduction (10 minutes)**
1. **Welcome and Attendance (2 minutes)**
- Greet the students and take attendance.
2. **Review Previous Lesson (5 minutes)**
- Briefly review the last session, focusing on the different types of chemical reactions (synthesis, decomposition, single replacement, and double replacement).
- Ask a few rapid-fire questions to recap.
3. **Introduction to Today's Topic (3 minutes)**
- State the objectives of today's lesson: exploring reversible/irreversible reactions and differentiating between endothermic and exothermic reactions.
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#### **Main Lesson (60 minutes)**
1. **Reversible and Irreversible Reactions (15 minutes)**
- **Define Terms:**
- Reversible reactions: reactions that can proceed in both forward and backward directions.
- Irreversible reactions: reactions that go to completion and cannot easily be reversed.
- **Examples and Diagrams:**
- Show diagrams of reversible reactions (e.g., Haber process for ammonia synthesis).
- Discuss irreversible reactions (e.g., combustion of gasoline).
- **Class Activity:**
- On the whiteboard, list various reactions and ask students to classify them as reversible or irreversible.
2. **Endothermic and Exothermic Reactions (15 minutes)**
- **Define Terms:**
- Endothermic reactions: reactions that absorb heat from the surroundings.
- Exothermic reactions: reactions that release heat to the surroundings.
- **Examples and Energy Diagrams:**
- Show examples with energy diagrams (e.g., endothermic - photosynthesis, exothermic - combustion).
- **Class Activity:**
- Distribute handouts and have students label whether given reactions are endothermic or exothermic.
3. **Lab Demonstrations (30 minutes)**
- **Safety Briefing (5 minutes):**
- Emphasize the importance of safety measures in the lab. Ensure all students wear goggles and gloves.
- **Demonstration 1: Endothermic Reaction:**
- Mix vinegar with baking soda. Record the temperature before and after the reaction.
- Discuss the drop in temperature.
- **Demonstration 2: Exothermic Reaction:**
- React magnesium ribbon with hydrochloric acid. Record the temperature before and after the reaction.
- Discuss the rise in temperature.
- **Class Activity:**
- Divide students into pairs, provide them with materials, and have them conduct the reactions themselves, recording observations.
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#### **Conclusion (10 minutes)**
1. **Summary (5 minutes)**
- Summarize the key points covered in the lesson: reversible vs. irreversible reactions and endothermic vs. exothermic reactions.
2. **Q&A Session (5 minutes)**
- Allow students to ask questions to clarify any doubts.
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#### **Homework Assignment:**
- Worksheet on classifying different chemical reactions (to be distributed at the end of the lesson).
- Read pages [insert pages] from the textbook on reaction energy profiles.
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#### **Assessment:**
- Participation during the class activities.
- Observation and accuracy during lab demonstrations.
- Homework assignment submission and correctness.
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### **Additional Notes:**
- Ensure that all safety protocols are strictly followed during lab demonstrations.
- Encourage students to think critically and ask questions during the lesson to foster a deeper understanding.
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