Contextualization

Electrolysis is a non-spontaneous process of oxidation-reduction reaction, where electrical energy is converted into chemical energy. It usually occurs in an electrolytic cell, which is composed of two electrodes (anode and cathode) connected to an external electrical energy source and immersed in a solution containing ions. Through the electrical energy provided, oxidation reactions occur at the anode and reduction reactions at the cathode.

In electrolysis, the so-called "ion displacement" occurs: cations are attracted to the cathode (negative) where they are reduced, while anions are attracted to the anode (positive) where they are oxidized. The compounds are thus decomposed into their elemental constituents. The concept of electrolysis is mainly used in the chemical industry, in processes such as water electrolysis, production of metals and gases, and in batteries.

Electrolysis is a topic of great importance. It plays a key role in many industrial and technological processes. The purification of metals, the production of chemical substances and the storage of energy are just a few examples of where this process is paramount. Water electrolysis, for example, can be used to produce hydrogen - a clean fuel that has the potential to replace fossil fuels. Furthermore, understanding this topic is essential to comprehending various modern technologies, such as lithium-ion batteries, for example.

We are constantly involved with products and processes that make use of electrolysis. A common example is the production of chlorine and caustic soda, which are essential for the manufacture of various products, from the bleach we use to clean our homes to the PVC present in numerous everyday objects. In addition, electrolysis is used in electroplating, a process of coating objects with a thin layer of metal - widely used in the jewelry and costume jewelry industry.

To begin your research and delve deeper into the topic, we suggest the following reliable sources:

1. Khan Academy: Deals in a very didactic and complete way with various science topics, including electrolysis. The platform has several videos and practical exercises that can assist students in their learning. Link to Khan Academy
2. Chemistry in Text: A chemistry teaching platform that covers everything from elementary school to higher education. It has a section dedicated to electrolysis with explanatory texts and resolved university entrance exam questions. Link to Chemistry in Text
3. Book "Principles of Chemistry: Questioning Modern Life and the Environment", 5th edition, by Nivaldo J. Tro. An excellent introduction to chemistry, covering a wide range of topics, including electrolysis.

Practical Activity

Activity Title: Electrolysis in Practice - Discovering Products and Understanding the Reactant

Project Objective

The objective of this activity is to provide students with the opportunity to perform an electrolysis experiment, verify the theory learned, identify the products formed and relate the results obtained to a practical everyday situation. In addition, one of the purposes is to improve students' teamwork, problem-solving and time management skills.

Detailed Project Description

Students, in groups of 3 to 5 people, will perform a saltwater electrolysis experiment (seawater), using simple materials. First, students will develop a work plan where they will establish a schedule for the experiment and divide the tasks among the group members. Subsequently, the students will assemble the electrolysis system, make the necessary records and, after performing the electrolysis, discuss the results and conclude the activity by preparing a report.

Required Materials

• Glass or transparent plastic container
• Seawater (or salt water)
• DC power supply (batteries or battery)
• Two wires with bare ends
• Two paper clips or similar metal pieces
• Plastic straws
• Mild soap

Detailed Step-by-Step Activity

1. Prepare the container with seawater (or salt water). Make sure the water is at room temperature.
2. Install the two paper clips or similar metal pieces at the ends of the wires and submerge them in the salt water container, without touching each other.
3. Connect the other end of the wires to the power supply, battery or battery.
4. Place the straws over each paper clip, positioning them so that they collect the gases released during the reaction.
5. Wait a few minutes and observe the bubbles that form on the electrodes.
6. After obtaining a sufficient amount of gas, interrupt the experiment and use the mild soap to produce soap bubbles with the collected gases. Observe the behavior of the bubbles.
7. Record all observations and results obtained to prepare the report.

Students must submit:

1. Work plan

The work plan must contain the schedule for the experiment and the division of tasks among the group members.

2. Experiment execution record

Record the step-by-step procedure of the experiment performed, showing photos, notes and observations.

3. Project Report

The report must contain the following points:

• Introduction: Explain what electrolysis is, its applications and the relevance of the experiment performed. Describe the objectives and importance of this activity.

• Development: Describe the theory behind electrolysis, the step-by-step experiment, the methodology used and the results obtained. The discussion of the results should be related to the practical and theoretical meaning of the experiment. For example, explain which gas was released at each electrode and why. What does this have to do with the formation of soap bubbles? What are the practical implications of this finding?

• Conclusion: Students should conclude the work by reviewing their main points, explaining what they learned and the conclusions drawn about the project. Relate the activity done with the theory studied on electrolysis. What were the difficulties encountered and how were they overcome? What was learned from the experiment and from the teamwork experience?

• Bibliography: Indicate the sources used to prepare the project, whether books, web pages, videos, etc.