Lesson plan of Basic Stoichiometry

Objectives (5 - 7 minutes)

1. Develop an understanding of basic concepts of stoichiometry, including the definition of stoichiometry, molecules, atoms, and the mole.

2. Apply stoichiometric theory to solve practical problems, such as calculating the quantity of a reactant required, or a product formed, in a chemical reaction.

3. Develop critical thinking and problem-solving skills, through working with stoichiometry problems, encouraging a systematic approach to problem-solving.

Secondary objectives:

• To encourage active participation from students through classroom discussions and hands-on activities, thus promoting collaborative learning.

• To spark students' interest in chemistry, by demonstrating its practical applications and relevance to the real world.

Introduction (10 - 12 minutes)

1. Review of prior knowledge: The teacher begins the lesson by recapping key chemistry concepts that underpin stoichiometry, such as atoms, molecules, atomic mass, and the idea of chemical reactions. It is important that students are familiar with these concepts in order to fully understand stoichiometry. (3 - 4 minutes)

2. Contextualising the problem: The teacher presents two word problems that involve stoichiometry. For example, "If you have 3 eggs, 2 cups of flour, and 1 cup of sugar, how many chocolate chip cookies can you make?" or "If you have 4 hydrogen atoms and 1 oxygen atom, how many water molecules can you make?" The purpose of these questions is to engage students and demonstrate the practical application of stoichiometry. (2 - 3 minutes)

3. Developing the context: The teacher develops the context by explaining the importance of stoichiometry, such as how it is used in various areas of science and industry. For example, in the manufacture of medicines, in the production of energy via chemical reactions, in agriculture to calculate the amount of fertilizer required, etc. (2 - 3 minutes)

4. Grabbing students' attention: The teacher shares an interesting fact or story related to stoichiometry. For example, the story of how stoichiometry was discovered by Amedeo Avogadro, a 19th-century Italian scientist, or the fact that stoichiometry is used to determine the amounts of ingredients needed to make the perfect French bread. (2 - 3 minutes)

Development (20 - 25 minutes)

1. Modelling activity: The teacher divides the class into groups of up to 5 students and presents them with a chocolate factory scenario. Each group is given a different "recipe" for a type of chocolate, listing the ingredients and their mass ratios. The challenge is to calculate how much of each ingredient is needed to produce a certain amount of chocolate, and then to test whether the amount of chocolate produced matches their prediction.

   • The teacher provides students with a periodic table, a digital balance, and calculators.

   • The students must identify the elements present in each ingredient, calculate how much of each element is in a given mass of the ingredient (using the molar mass), and finally, calculate the mass of each ingredient required to make the desired amount of chocolate.

   • Once the calculations are complete, the students weigh out the ingredients and make the chocolate. They should record the amount of chocolate produced and compare it to their prediction.

   • This activity aims to demonstrate the concept of stoichiometry in a practical and engaging way, showing students how the calculations they do in class have real-world applications.

2. Group discussion: Following the modelling activity, the teacher facilitates a group discussion. Each group should discuss and present to the class their findings, difficulties, and solutions encountered during the activity.

   • The teacher guides the discussion, asking questions of the groups and encouraging participation from all.

   • The purpose of this activity is to encourage students to reflect on their learning, to clarify any misconceptions, and to consolidate their understanding of stoichiometry.

3. Problem-solving: The teacher sets a series of stoichiometry problems for the students to solve individually.

   • The problems should be varied, involving different types of stoichiometric calculations and applying the concept to different contexts (e.g. problems involving chemical reactions, mixtures of substances, production of materials, etc.).

   • Students are given a set amount of time to complete the problems. During this time, the teacher circulates around the room, clarifying any misconceptions and providing guidance where necessary.

   • After the time is up, the teacher goes through the problems with the class, explaining each step and clarifying any misconceptions that arise.

   • The purpose of this activity is to deepen students' understanding of stoichiometry and to develop their problem-solving skills.

Debrief (8 - 10 minutes)

1. Group discussion (3 - 4 minutes): The teacher begins the debrief by facilitating a general discussion with the class. Each group has a maximum of 3 minutes to share their solutions or conclusions from the activities they carried out. During the presentations, the teacher should ask students to explain the strategies they used to solve the problems and to justify their answers. This will encourage student reflection and argumentation, reinforcing their learning and clearing up any misconceptions.

2. Connecting with theory (2 - 3 minutes): After the presentations, the teacher draws connections between the hands-on activities and the theory of stoichiometry. For example, the teacher might highlight how the calculations students carried out during the modelling activity are similar to the stoichiometric calculations they have been studying in class. It is important for students to see the practical application of the theory, as this can help consolidate their learning.

3. Individual reflection (2 - 3 minutes): To conclude, the teacher asks students to reflect individually on what they have learnt in the lesson. The teacher asks some guiding questions, such as:

   1. What was the most important concept you learnt today?
   2. What questions do you still have?
   3. How could you apply what you have learnt today to real-life situations?

   The teacher gives students a minute to think about each question. After this time, students can share their answers with the class, if they wish. This reflection stage helps students to consolidate their learning and to identify any gaps in their understanding, which can be addressed in future lessons.

4. Feedback (1 minute): The teacher thanks everyone for their participation and reinforces the importance of feedback for continually improving the teaching and learning process. The teacher encourages students to share any questions, suggestions, or comments about the lesson, either in person or via other communication channels.

Conclusion (5 - 7 minutes)

1. Content summary (2 - 3 minutes): The teacher recaps the main points covered during the lesson, reinforcing the definition of stoichiometry, the importance of stoichiometric calculations in chemistry, and the practical applications of these concepts. The teacher also highlights the key skills that students have developed during the lesson, such as critical thinking, problem-solving, and teamwork.

2. Connection between theory, practice, and applications (1 - 2 minutes): The teacher draws attention to how the lesson has connected theory, practice, and applications. For example, the teacher might mention how the stoichiometric calculations carried out during the modelling activity are a practical application of stoichiometric theory. Furthermore, the teacher might reinforce how stoichiometry is used in various fields of science and industry, which demonstrates the relevance of what has been learnt.

3. Additional resources (1 minute): The teacher suggests some additional resources for those students who wish to extend their knowledge of stoichiometry. These resources might include educational videos, chemistry websites, textbooks, etc. The teacher may also provide some additional practice exercises for students to complete at home.

4. Significance of the topic (1 - 2 minutes): Lastly, the teacher highlights the significance of stoichiometry in everyday life and in a variety of careers. For example, the teacher might mention how stoichiometry is used in the food industry to determine the amount of ingredients required in a recipe, or in medicine to calculate the amount of a drug that should be given to a patient. The aim is to show students that what they have learnt in the lesson has real-world applications and is relevant to their lives.