Electrochemistry in Action: Exploring Batteries and Redox Reactions

Objectives

1. Understand what a battery is and how redox reactions work.

2. Comprehend the movement of electrons and current, checking which materials can be consumed or deposited.

3. Identify the anode and cathode in an electrochemical cell.

Contextualization

Electrochemistry is present in many aspects of our daily lives, from the batteries that power our electronic devices to the industrial processes that involve the galvanization of metals. The study of redox reactions and the functioning of batteries is fundamental to understanding how electrical energy can be generated and used efficiently. For example, lithium batteries used in smartphones and electric cars are direct applications of electrochemistry. Another example is galvanization, a process that protects metal structures from corrosion, widely used in construction and the automotive industry.

Relevance of the Theme

Knowledge of electrochemistry is crucial in the current context due to the increasing use of electronic devices and the search for more efficient and sustainable energy sources. Understanding redox reactions and how batteries work not only aids in technological innovation in areas such as battery production and the galvanization of metals but also opens doors to careers in chemistry, engineering, and materials science. Additionally, electrochemical technologies play a vital role in energy storage from renewable sources such as the sun and wind, contributing to a more sustainable future.

Electrochemical Cell

An electrochemical cell is a device that converts chemical energy into electrical energy through redox reactions. It consists of two electrodes (anode and cathode) and an electrolyte that allows the movement of ions. This concept is fundamental for the development of batteries and other energy storage devices.

• Converts chemical energy into electrical energy

• Composed of two electrodes: anode and cathode

• Uses an electrolyte to allow the movement of ions

Redox Reactions

Redox reactions involve the transfer of electrons between chemical substances. In oxidation, a substance loses electrons, while in reduction, a substance gains electrons. These reactions are essential for the functioning of electrochemical cells.

• Involves the transfer of electrons

• Oxidation: loss of electrons

• Reduction: gain of electrons

• Essential for the functioning of batteries

Movement of Electrons and Electric Current

The movement of electrons is what generates electric current in an electrochemical cell. Electrons move from the anode to the cathode through an external circuit, while ions move within the electrolyte solution to balance the charge.

• Generates electric current

• Electrons move from the anode to the cathode

• Ions move in the electrolyte solution to balance charge

Anode and Cathode

The anode is the electrode where oxidation (loss of electrons) occurs, while the cathode is the electrode where reduction (gain of electrons) occurs. Correct identification of these electrodes is crucial for the proper functioning of an electrochemical cell.

• Anode: where oxidation (loss of electrons) occurs

• Cathode: where reduction (gain of electrons) occurs

• Correct identification is crucial for the functioning of the cell

Practical Applications

• Lithium batteries in smartphones and electric cars: use redox reactions to store and release energy.
• Metal galvanization: a protective process against corrosion using electrochemistry.
• Renewable energy storage: electrochemical technologies are used to store energy from sources like the sun and wind.

Key Terms

• Electrochemistry: the study of chemical reactions that involve the transfer of electrons.

• Redox Reactions: chemical reactions that involve the transfer of electrons between substances.

• Electrochemical Cell: a device that converts chemical energy into electrical energy.

• Anode: electrode where oxidation (loss of electrons) occurs.

• Cathode: electrode where reduction (gain of electrons) occurs.

• Electric Current: flow of electrons through a conductor.

Questions

• How can understanding redox reactions impact technological innovation in areas like battery production?

• In what ways do electrochemical cells contribute to sustainability in the context of renewable energy?

• What challenges are faced in the application of electrochemistry in industrial processes such as galvanization?

Conclusion

To Reflect

Today's lesson on Electrochemistry showed us the importance of redox reactions and the functioning of electrochemical cells in our daily lives and industry. Understanding how electrons move and how chemical energy is converted into electrical energy is fundamental for the development of technologies such as lithium batteries and galvanization processes. This knowledge not only broadens our scientific understanding but also opens doors to innovations that can contribute to a more sustainable and technologically advanced world.

Mini Challenge - Practical Challenge: Building a Lemon Battery

Let's build a battery using lemons and common materials to understand in practice how an electrochemical cell works and observe the generation of electric current.

• Gather the following materials: 3 lemons, 3 copper coins, 3 galvanized nails, electrical wires, and a voltmeter.
• Insert a copper coin and a galvanized nail into each lemon, making sure they do not touch.
• Connect the lemons in series using the electrical wires: connect the nail of one lemon to the copper coin of the next lemon.
• Connect the free terminals (one copper coin and one galvanized nail) to the voltmeter to measure the generated voltage.
• Note the voltmeter reading and observe the generation of electric current.
• Reflect on what is happening in terms of electron movement and redox reactions.