Summary of Electrochemistry: Introduction

Goals

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

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

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

Contextualization

Electrochemistry is part of our everyday lives, from the batteries that power our gadgets to industrial practices like the galvanization of metals. Learning about redox reactions and battery operation is crucial for understanding how electrical energy can be effectively generated and utilised. For example, lithium batteries found in smartphones and electric vehicles are practical examples of electrochemistry in action. Similarly, galvanization protects metal structures from rust, making it essential in construction and the automotive sector.

Subject Relevance

To Remember!

Electrochemical Cell

An electrochemical cell is a device that converts chemical energy to electrical energy through redox reactions. It comprises two electrodes (anode and cathode) and an electrolyte that facilitates ion movement. This concept is key to creating batteries and other energy storage devices.

• Converts chemical energy into electrical energy

• Composed of two electrodes: anode and cathode

• Utilises an electrolyte to facilitate ion movement

Redox Reactions

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

• Involve the transfer of electrons

• Oxidation: loss of electrons

• Reduction: gain of electrons

• Essential for the operation of batteries

Movement of Electrons and Electrical Current

The flow of electrons generates electrical current within an electrochemical cell. Electrons travel from the anode to the cathode through an external circuit, while ions move in the electrolyte to maintain charge balance.

• Generates electrical current

• Electrons move from the anode to the cathode

• Ions move within the electrolyte to maintain charge balance

Anode and Cathode

The anode is the electrode where oxidation (loss of electrons) occurs, whereas the cathode is the electrode where reduction (gain of electrons) takes place. Correctly identifying these electrodes is essential for the effective functioning of an electrochemical cell.

• Anode: where oxidation (loss of electrons) occurs

• Cathode: where reduction (gain of electrons) occurs

• Accurate identification is crucial for the battery's performance

Practical Applications

• Lithium batteries in smartphones and electric cars: use redox reactions to store and release energy.

• Metal galvanization: a process that protects against corrosion using electrochemistry.

• Renewable energy storage: electrochemical technologies are employed for storing energy from sources like solar and wind.

Key Terms

• Electrochemistry: the study of chemical reactions involving electron transfer.

• 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.

• Electrical Current: the flow of electrons through a conductor.

Questions for Reflections

• How can understanding redox reactions drive innovation in battery production?

• In what ways do electrochemical cells contribute to sustainability in renewable energy contexts?

• What challenges are encountered when applying electrochemistry in industrial processes like galvanization?

Practical Challenge: Building an Orange Battery

Let's create a battery using oranges and common materials to practically understand how an electrochemical cell works and observe the generation of electrical current.

Instructions

• Gather the following materials: 3 oranges, 3 copper coins, 3 galvanized nails, electrical wires, and a voltmeter.

• Insert a copper coin and a galvanized nail into each orange, making sure they do not touch.

• Connect the oranges in series using electrical wires: link the nail of one orange to the copper coin of the next orange.

• Connect the free terminals (one copper coin and one galvanized nail) to the voltmeter to measure the voltage generated.

• Record the voltmeter reading and observe the production of electrical current.

• Reflect on what is happening regarding electron movement and redox reactions.