Project: Equilibrium at Your Fingertips

Contextualization

Chemical Equilibrium, especially the Le Chatelier's principle, is a fundamental part of Chemistry that helps explain how chemical reactions behave. This principle, formulated by the French chemist Henri Louis Le Chatelier, states that when a system in equilibrium is perturbed, it adjusts to minimize the perturbation. This can happen for several reasons, such as changes in concentration, temperature, and pressure.

Chemical reactions are not only performed in a lab as an experiment, they are all around us, all the time. When you open a soda, when a car is being fueled, when a plant is performing photosynthesis, all of these situations involve chemical reactions that are, in some way, in equilibrium.

Importance of the Subject

Why does this matter? This concept has a wide range of applications from the industry to our daily lives. In the chemical industry, for example, Le Chatelier's principle is used to maximize the efficiency of chemical reactions, generating more product with less resources. In our body, the biochemical reactions that keep us alive are in constant equilibrium, and any unbalance may lead to health issues.

Indeed, this idea of equilibrium is a fundamental principle in life and nature, not just in chemistry but in several other scientific fields as well. For example, ecologists study how ecosystems adapt to perturbations, such as the invasion of an exotic species or a climate change.

Hands-on Activity: "Equilibrium at Your Fingertips"

Goal

The goal of this activity is to allow students to experience Le Chatelier's Principle first-hand through a simple, safe, and illustrative hands-on experiment.

Project Description

Students will be divided into groups of 3 to 5 students, in which each group will be responsible for carrying out the experiment, documenting its results, and presenting their conclusions in a clear and concise manner through a written report.

The project will take one week, with an average time commitment of two to four hours per student. The experiment itself will take just a few minutes, but the preparation, discussion, documentation, and reflection should be carried out with care.

Materials

• 2 clear glass jars
• White vinegar
• Baking soda
• Water
• Food coloring
• Thermometer

Step-by-Step Instructions

1. In a first jar, add a known amount of baking soda.
2. In a second jar, add a known amount of white vinegar.
3. Add some drops of food coloring in both jars, in order to help visualize the experiment.
4. Take the initial temperature of both liquids, in both jars.
5. Now, slowly add the vinegar from the second jar to the first jar with the baking soda, allowing them to mix.
6. Notice that some kind of "bubbling" happens. This is the chemical reaction taking place.
7. Continue to slowly add the vinegar to the baking soda, until there is no more "bubbling".
8. In the end, check and write down the temperature of the solution.

Project Deliverables and Written Report

After the experiment, each group should meet to discuss and analyze their results. Then, they should prepare a written report containing the following sections:

1. Introduction - Students should contextualize Le Chatelier's Principle, its relevance, and its application in their experiment and in the real world.
2. Development - Students should present the theory behind Le Chatelier's Principle, explain in detail their experiment, indicate their methodology, and present and discuss their results.
3. Conclusion - Students should reflect on their experiment's results, the findings, and what they have learned throughout the process.
4. Bibliography - Students should indicate the sources they have consulted to work on the project, including books, web pages, videos, etc.

This report should be handed in to the instructor by the end of the week, and each student should be prepared to discuss the results of their group with the classroom.