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Britain & the wider world: 1745 -1901
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Chemistry
5 Dec 2025
174
1 page
Peri <3 @peristudies
Chemical formulae and equations might seem daunting at first, but they're actually just a clever shorthand system that... Show more
Ever wondered how chemists communicate complex reactions so simply? State symbols are your first key to cracking the code. These little letters in brackets - (s) for solid, (l) for liquid, (g) for gas, and (aq) for aqueous - tell you exactly what physical state each substance is in during a reaction.
Ionic equations are like the highlights reel of chemistry reactions. They cut through the noise and only show you the ions that actually matter - the ones doing the real work. Spectator ions are basically the chemistry equivalent of bystanders; they're present but don't actually participate in the reaction, so we leave them out of ionic equations to keep things clear.
When it comes to chemical formulas, you've got two main types to master. Molecular formulas like C₆H₁₂O₆ show you exactly how many atoms of each element are in a molecule. Empirical formulas like CH₂O give you the simplest whole number ratio of elements - think of it as the stripped-down version.
Exam Tip Always include state symbols in your ionic equations - they're often worth crucial marks that students lose unnecessarily!
Understanding moles is absolutely essential for chemistry success. A mole is simply a way of counting particles - specifically, it contains as many particles as there are atoms in 12g of carbon-12. Stoichiometry uses this concept to show you the exact proportions in which substances react, making calculations much more manageable.
The main types of reactions follow predictable patterns. Combination reactions bring substances together, decomposition reactions break them apart, displacement reactions involve one element muscling in to replace another, and exchange reactions see positive ions swapping partners like a chemical dance.
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.
0
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the process of preparing a volumetric solution and conducting an acid-base titration to determine the concentration of sodium hydroxide. This practical guide covers essential laboratory techniques, chemical calculations, and safety precautions, ensuring a comprehensive understanding of titration methods. Ideal for chemistry students seeking to master titration skills and laboratory practices.
Chemistrygrade 7+ gcse combined science notes
ChemistryExplore essential laboratory techniques in chemical analysis, including stoichiometric calculations, gravimetric analysis, and the use of various chemical apparatus such as conical flasks and digital balances. This summary provides insights into acid-base titrations and methods for improving percentage yield in reactions.
ChemistryExplore essential concepts in A Level Chemistry, including mole calculations, Avogadro's constant, atomic structure, and empirical formulas. This resource provides clear explanations and key formulas to enhance your understanding of chemical principles. Ideal for exam preparation and mastering foundational topics in chemistry.
ChemistryComprehensive summary of Unit 1: Chemical Changes and Structure for National 5 Chemistry. This resource covers key concepts such as atomic structure, chemical bonding, reaction kinetics, acid-base reactions, and stoichiometry. Ideal for revision and exam preparation.
ChemistryExplore essential mole calculations and stoichiometry concepts for A-Level Chemistry. This study resource covers the amount of substance, back titration methods, and detailed examples to enhance your understanding of chemical calculations. Perfect for exam preparation and mastering key concepts.
ChemistryQuotes from every main character
English LiteratureApp 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
Peri <3
@peristudies
Chemical formulae and equations might seem daunting at first, but they're actually just a clever shorthand system that chemists use to describe what's happening in reactions. Once you understand the basics of state symbols, different types of equations, and how... Show more
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Ever wondered how chemists communicate complex reactions so simply? State symbols are your first key to cracking the code. These little letters in brackets - (s) for solid, (l) for liquid, (g) for gas, and (aq) for aqueous - tell you exactly what physical state each substance is in during a reaction.
Ionic equations are like the highlights reel of chemistry reactions. They cut through the noise and only show you the ions that actually matter - the ones doing the real work. Spectator ions are basically the chemistry equivalent of bystanders; they're present but don't actually participate in the reaction, so we leave them out of ionic equations to keep things clear.
When it comes to chemical formulas, you've got two main types to master. Molecular formulas like C₆H₁₂O₆ show you exactly how many atoms of each element are in a molecule. Empirical formulas like CH₂O give you the simplest whole number ratio of elements - think of it as the stripped-down version.
Exam Tip: Always include state symbols in your ionic equations - they're often worth crucial marks that students lose unnecessarily!
Understanding moles is absolutely essential for chemistry success. A mole is simply a way of counting particles - specifically, it contains as many particles as there are atoms in 12g of carbon-12. Stoichiometry uses this concept to show you the exact proportions in which substances react, making calculations much more manageable.
The main types of reactions follow predictable patterns. Combination reactions bring substances together, decomposition reactions break them apart, displacement reactions involve one element muscling in to replace another, and exchange reactions see positive ions swapping partners like a chemical dance.
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.
0
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Explore the process of preparing a volumetric solution and conducting an acid-base titration to determine the concentration of sodium hydroxide. This practical guide covers essential laboratory techniques, chemical calculations, and safety precautions, ensuring a comprehensive understanding of titration methods. Ideal for chemistry students seeking to master titration skills and laboratory practices.
Chemistrygrade 7+ gcse combined science notes
ChemistryExplore essential laboratory techniques in chemical analysis, including stoichiometric calculations, gravimetric analysis, and the use of various chemical apparatus such as conical flasks and digital balances. This summary provides insights into acid-base titrations and methods for improving percentage yield in reactions.
ChemistryExplore essential concepts in A Level Chemistry, including mole calculations, Avogadro's constant, atomic structure, and empirical formulas. This resource provides clear explanations and key formulas to enhance your understanding of chemical principles. Ideal for exam preparation and mastering foundational topics in chemistry.
ChemistryComprehensive summary of Unit 1: Chemical Changes and Structure for National 5 Chemistry. This resource covers key concepts such as atomic structure, chemical bonding, reaction kinetics, acid-base reactions, and stoichiometry. Ideal for revision and exam preparation.
ChemistryExplore essential mole calculations and stoichiometry concepts for A-Level Chemistry. This study resource covers the amount of substance, back titration methods, and detailed examples to enhance your understanding of chemical calculations. Perfect for exam preparation and mastering key concepts.
ChemistryQuotes from every main character
English LiteratureApp 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