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Chemistry
7 Dec 2025
267
3 pages
Munsif Shameem @munsifshameem
Redox reactions are everywhere - from the batteries in your phone to the bleach cleaning your clothes. Understanding... Show more
Oxidation means losing electrons, whilst reduction means gaining electrons. You can remember this with the acronym "OIL RIG" - Oxidation Is Loss, Reduction Is Gain. These processes always happen together in what we call redox reactions.
Oxidising agents are the electron acceptors - they take electrons from other substances and cause oxidation to happen. Meanwhile, reducing agents are electron donors that give away electrons and cause reduction. Think of them as opposite players in the same game.
The electrochemical series (ECS) shows you exactly where to find these agents. Oxidising agents hang out in the bottom left, whilst reducing agents prefer the top right. This positioning isn't random - it's based on how desperately each substance wants or gives up electrons.
Quick Tip Elements with high electronegativity (like halogens) make brilliant oxidising agents because they're electron-greedy, whilst low electronegativity elements (like alkali metals) are generous electron donors.
The halogens (Group 7) are your strongest oxidising agents because they desperately want to gain that extra electron to complete their outer shell. On the flip side, alkali metals (Group 1) are champion reducing agents since they're happy to lose their single outer electron.
You'll encounter specific oxidising agents regularly potassium permanganate (KMnO₄), acidified potassium dichromate (K₂Cr₂O₇), and hydrogen peroxide (H₂O₂). These are powerful electron acceptors used in many reactions.
Common reducing agents include all alkali metals, hydrogen gas (H₂), and carbon monoxide (CO). These substances readily donate electrons to other reactants.
Oxidising agents are incredibly useful in real life - they kill bacteria and fungi, inactivate viruses, and break down coloured compounds (that's how bleach works!). Understanding their electron-accepting nature helps explain why they're so effective at these jobs.
Exam Focus Learn to identify whether a substance is an oxidising or reducing agent by looking at its position in the electrochemical series - this comes up frequently in exam questions.
The electrochemical series is your roadmap for predicting redox reactions. It's arranged as a series of reduction reactions, with the strongest reducing agents at the top right and strongest oxidising agents at the bottom left.
When balancing ion-electron equations, follow this systematic approach balance atoms first, then add water molecules, then hydrogen ions, and finally electrons. Combine these balanced ion-electron equations to create complete redox equations.
Here's the key strategy if you need something to act as a reducing agent, look above and to the right in the ECS. For oxidising agents, look below and to the left. This positioning reflects each substance's electron-donating or accepting tendencies.
Remember the logic behind Group 1 and Group 7 elements. Group 7 elements want to gain electrons (making them oxidising agents), whilst Group 1 elements want to lose electrons (making them reducing agents). This electron behaviour drives all redox chemistry.
Success Strategy Master the ECS layout and you'll be able to predict which reactions are possible and write balanced equations confidently - essential skills for your A-level exams.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
13
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Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Electron (Redox) reduction
ChemistryExplore the reactivity of metals, including displacement reactions and methods of extraction. This summary covers key concepts such as oxidation, reduction, and the behavior of alkali and alkaline earth metals with water and acids. Ideal for students preparing for chemistry exams.
ChemistryApp Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Munsif Shameem
@munsifshameem
Redox reactions are everywhere - from the batteries in your phone to the bleach cleaning your clothes. Understanding how electrons move between substances through oxidation and reduction is crucial for mastering A-level chemistry and will help you tackle those tricky... Show more
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Join milions of students
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Oxidation means losing electrons, whilst reduction means gaining electrons. You can remember this with the acronym "OIL RIG" - Oxidation Is Loss, Reduction Is Gain. These processes always happen together in what we call redox reactions.
Oxidising agents are the electron acceptors - they take electrons from other substances and cause oxidation to happen. Meanwhile, reducing agents are electron donors that give away electrons and cause reduction. Think of them as opposite players in the same game.
The electrochemical series (ECS) shows you exactly where to find these agents. Oxidising agents hang out in the bottom left, whilst reducing agents prefer the top right. This positioning isn't random - it's based on how desperately each substance wants or gives up electrons.
Quick Tip: Elements with high electronegativity (like halogens) make brilliant oxidising agents because they're electron-greedy, whilst low electronegativity elements (like alkali metals) are generous electron donors.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The halogens (Group 7) are your strongest oxidising agents because they desperately want to gain that extra electron to complete their outer shell. On the flip side, alkali metals (Group 1) are champion reducing agents since they're happy to lose their single outer electron.
You'll encounter specific oxidising agents regularly: potassium permanganate (KMnO₄), acidified potassium dichromate (K₂Cr₂O₇), and hydrogen peroxide (H₂O₂). These are powerful electron acceptors used in many reactions.
Common reducing agents include all alkali metals, hydrogen gas (H₂), and carbon monoxide (CO). These substances readily donate electrons to other reactants.
Oxidising agents are incredibly useful in real life - they kill bacteria and fungi, inactivate viruses, and break down coloured compounds (that's how bleach works!). Understanding their electron-accepting nature helps explain why they're so effective at these jobs.
Exam Focus: Learn to identify whether a substance is an oxidising or reducing agent by looking at its position in the electrochemical series - this comes up frequently in exam questions.
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
The electrochemical series is your roadmap for predicting redox reactions. It's arranged as a series of reduction reactions, with the strongest reducing agents at the top right and strongest oxidising agents at the bottom left.
When balancing ion-electron equations, follow this systematic approach: balance atoms first, then add water molecules, then hydrogen ions, and finally electrons. Combine these balanced ion-electron equations to create complete redox equations.
Here's the key strategy: if you need something to act as a reducing agent, look above and to the right in the ECS. For oxidising agents, look below and to the left. This positioning reflects each substance's electron-donating or accepting tendencies.
Remember the logic behind Group 1 and Group 7 elements. Group 7 elements want to gain electrons (making them oxidising agents), whilst Group 1 elements want to lose electrons (making them reducing agents). This electron behaviour drives all redox chemistry.
Success Strategy: Master the ECS layout and you'll be able to predict which reactions are possible and write balanced equations confidently - essential skills for your A-level exams.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
13
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Electron (Redox) reduction
ChemistryExplore the reactivity of metals, including displacement reactions and methods of extraction. This summary covers key concepts such as oxidation, reduction, and the behavior of alkali and alkaline earth metals with water and acids. Ideal for students preparing for chemistry exams.
ChemistryApp Store
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Sociology