Contextualization

Introduction

The fascinating world of chemistry is filled with numerous substances and compounds that are essential for our daily lives. Aldehydes, a group of organic compounds, are particularly important and present in various everyday elements.

Aldehydes are carbonilic organic compounds, which means they contain a functional group formed by a carbon linked to an oxygen (C=O), known as a carbonyl group, at the end of a carbon chain. This characteristic gives aldehydes unique properties that differentiate them from other groups of organic compounds.

This project aims to explore the universe of aldehydes, what they are, their properties, characteristics, and why they are so important for chemistry and other fields of science. Our goal will be to discover how these components interact with the world around us and how we can work with them efficiently and safely.

Contextualization

Aldehydes are widely used in various industries, for example, formaldehyde is one of the main preservatives in anatomy and biology laboratories, as well as being used in the production of resins and plastics. Another example is benzaldehyde, widely employed in the fragrance industry due to its pleasant almond smell. Furthermore, some aldehydes play a relevant role in biochemistry, such as glucose and other reducing sugars.

Understanding aldehydes enables us to better comprehend the world around us and to conduct more effective research and experiments. Gaining proficiency in handling these compounds enhances our competence as scientists and opens up new paths for discovery.

Practical Activity

Activity Title: "The Exploration of the World of Aldehydes"

Project Objective

The objective of this project is to take you, dear students, on a practical adventure to discover the world of aldehydes, exploring their properties, characteristics, and applications.

Students will be divided into groups of 3 to 5 members, and you will have one month to carry out the following tasks:

Project Description

Part I: Theoretical Research

Your group must conduct a detailed research on aldehydes. Your work should include:

• What are aldehydes and how are they classified
• The physical and chemical properties of aldehydes
• Some examples of aldehydes in everyday life and their applications
• The risks associated with handling aldehydes and safety measures

Part II: Practical Experiment

Perform an experiment that exemplifies the properties of aldehydes. The proposed experiment is the creation and testing of a Tollens' test (or "silver mirror"), used in laboratories to determine the presence of aldehydes.

Required Materials

• Silver nitrate solution (AgNO3)
• Diluted sodium hydroxide solution (NaOH)
• Ammonia solution (NH3)
• Erlenmeyer flask
• Glass rod
• Aldehyde of your choice (for example, glyceraldehyde)
• Water bath
• Safety goggles, gloves, and lab coat

Step by Step

1. Wear safety equipment.
2. Add a few drops of sodium hydroxide solution to the silver nitrate solution in the Erlenmeyer flask.
3. Slowly add ammonia solution until the precipitate formed in the previous step completely dissolves, leaving the solution slightly yellowish. You will obtain the Tollens' reagent.
4. Then, add a few drops of the aldehyde of your choice.
5. Heat the flask in a water bath, gently stirring with a glass rod.
6. Observe the appearance of a silver mirror inside the flask, indicative of the presence of aldehydes (reduction of Ag+ ions to Ag0).

Project Deliverables

Once the practical activity is completed, each group must prepare a well-structured report containing the following elements:

1. Introduction

In this section, contextualize the theme, the relevance of aldehydes and their application in the real world, as well as the objective of this project.

2. Development

Explain the theory behind aldehydes. Describe the experiment you conducted in detail, including the purpose of each step and how they relate to the theory you researched.

3. Results and Discussion

Present and discuss the results obtained in the experiment. What do they suggest about the properties of aldehydes? How do they align with what you learned in the theoretical research?

4. Conclusions

Conclude the work, summarizing its main points, explaining the lessons learned, and drawing conclusions about aldehydes and your project.

5. Bibliography

Indicate the reference sources used during the project.

The report should be written clearly, objectively, and coherently, with language suitable for a scientific work. This report will be a fundamental part of the evaluation of this project.

Remember that this project will assess not only your knowledge of aldehydes but also your ability to work in a team, manage your time, solve problems, and think creatively.