Photo Credit: Aqua Mechanical (CreatIve Commons)Today, we shall discuss on the Basic Concepts of Electrolytic Cells in Electrolysis. This is a very important concept when it comes to Secondary 4 O-Level Pure Chemistry and IP Advanced Chemistry Examinations.
Basic Concepts of Electrolytic Cells in Electrolysis
Electrolysis is the decomposition of a compound using electricity.
During electrolysis, electrical energy is converted into chemical energy to bring about a chemical change.
The apparatus used for electrolysis is called an Electrolytic Cell and it consists of 3 main components:
- Battery or Power Source
- Electrodes
- Electrolytes
It consists of two electrodes in an electrolyte.
An electrode is essentially a rod or plate where electricity enters or leaves an electrolyte during electrolysis.
An electrolyte could be an ionic compound in molten state or dissolved in aqueous solution, or an acid or alkali solution. Presence of mobile ions allows it to conducts an electric current and is decomposed in the electrolysis process.
A direct current power source or battery is connected to the electrodes.
An electric current will flow through the electrolyte, decomposing it into simpler substances.
Cathode is the negative electrode connected to the negative terminal of the battery or power source.
Anode is the positive electrode connected to the positive terminal of the battery or power source.
Cation, which is an ion having a positive charge, will be attracted to the negatively charged cathode and gets reduced.
Anion, which is an ion having a negative charge, will be attracted to the positively charged anode and gets oxidised.
Note that during electrolysis, reactions only occur at the electrodes and not inside the electrolyte.
The reaction which takes place during electrolysis is a redox reaction.
Oxidation occurs at the anode while reduction occurs at the cathode.
Strategy (acronym) to remember this concept easily is by using AN OX; RED CAT.
YouTube Video Tutorial on Electrolytic Cells
In the YouTube Video below, you will learn from Mr Sean Chua in a step-by-step manner on how electrolysis occurs in Electrolytic Cells. He is a highly recommended O-Level Pure Chemistry Tuition Teacher (Tutor Specialist) with 19 years of teaching experience and invited book author for the MOE approved O-Level Pure Chemistry Ten Years Series Books.
Length of Video: 11.09 minutes
Direct Video Link: https://youtu.be/7OaB0nyHPtA
I hope you find the content easy for your understanding and if you have any questions, leave me a comment below. Feel free to share this blog post with your friends and learn the key O-Level Pure Chemistry concepts together.
In the next blog post, i will be sharing a video on Selective Discharge of Ions in Electrolytic Cells based on the Position of Reactivity Series & Concentration Effect. Do stay tuned to it!
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PS: Under related articles below, there are several blog post discussions and questions related to Electrolysis concepts. You can also do a keyword search using the search box at the top right hand corner.
Related Articles:
- O Level Chemistry – Definitions of Electrolysis
- O Level Chemistry – Strategies to Predict Products of Electrolysis for Aqueuous Solutions
- O Level Chemistry – Secrets of Redox & Electrolysis Series
- O Level Chemistry – Products of Electrolysis of Molten Compound
- O Level Chemistry – Strategies to Predict Products of Electrolysis for Aqueuous Solutions
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