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chemistry - c8 (chemical analysis)
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5 Jul 2025
•
Easy Chromatography Steps and Cool Gas Tests!
lewis beet
@lewisbeet
Chromatography Practical and Gas Tests
This page provides a detailed guide on conducting a chromatography experiment and outlines tests for identifying common gases. These chromatography practical steps and gas tests are fundamental skills in chemistry laboratories.
The chromatography practical is described in eight steps:
- Draw a pencil line 1cm from the bottom of the chromatography paper.
- Add ink dots using a pipette or pen, ensuring they don't merge.
- Pour solvent into a beaker, just enough to touch the chromatography paper.
- Place the paper in the beaker and allow the solvent to move up.
- Remove the paper before the solvent reaches the top and let it dry.
- Measure the distance travelled by the solvent.
- Measure the distance travelled by each ink spot.
- Calculate and compare Rf values for each ink spot.
Highlight: The importance of pure substances in chemistry is evident in chromatography, where the purity of a substance can be determined by the number of spots produced.
The page then describes tests for identifying four common gases:
Example: Test for hydrogen, oxygen, carbon dioxide, chlorine:
- Hydrogen: A burning splint at the opening of a test tube produces a rapid burn with a squeaky pop.
- Oxygen: A glowing splint relights in the presence of oxygen.
- Carbon Dioxide: Calcium hydroxide turns cloudy when shaken with carbon dioxide.
- Chlorine: Damp litmus paper is bleached white in the presence of chlorine.
These gas tests are crucial for identifying the products of chemical reactions and understanding the properties of different substances.
Vocabulary: Litmus paper is an indicator used to test the acidity or alkalinity of a solution, but in this context, it's used to detect the presence of chlorine through its bleaching effect.
Understanding Pure Substances and Chromatography in Chemistry
This page introduces fundamental concepts in chemistry, focusing on the nature of pure substances and the technique of chromatography. It provides essential definitions and explanations crucial for understanding chemical composition and separation methods.
Definition: Pure substances contain only one type of element or compound and are in their natural state without any additions.
The page distinguishes between elements, compounds, and mixtures:
- Elements are composed of one type of atom.
- Compounds consist of two or more elements chemically joined together.
- Mixtures contain two or more elements or compounds that are not chemically bonded.
Vocabulary: Formulations are specific mixtures of compounds or substances that do not react together but produce a useful product for a particular function, such as deodorants or sunscreams.
The concept of chromatography is introduced as a method to separate mixtures of soluble substances. It involves two phases: mobile and stationary.
Highlight: In chromatography, pure substances produce a single spot, while impure substances result in two or more spots.
The page also explains the calculation of Rf values in chromatography:
Rf = distance travelled by substance / distance travelled by solvent
An illustration demonstrates the chromatography process, showing the separation of different colored inks on chromatography paper.
Example: A chromatography setup is shown with blue, green, yellow, and black ink spots separated on paper, with the solvent front reaching 10cm and one substance traveling 8cm.
We thought you’d never ask...
What is the Knowunity AI companion?
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.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
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Students love us — and so will you.
4.9/5
App Store
4.8/5
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
Easy Chromatography Steps and Cool Gas Tests!
lewis beet
@lewisbeet
This practical guide covers key concepts in chemistry, focusing on pure substances, mixtures, and chromatography. It also includes tests for identifying common gases. The information is essential for understanding fundamental chemical principles and laboratory techniques.
- Pure substances, elements, and compounds... Show more
Chromatography Practical and Gas Tests
This page provides a detailed guide on conducting a chromatography experiment and outlines tests for identifying common gases. These chromatography practical steps and gas tests are fundamental skills in chemistry laboratories.
The chromatography practical is described in eight steps:
- Draw a pencil line 1cm from the bottom of the chromatography paper.
- Add ink dots using a pipette or pen, ensuring they don't merge.
- Pour solvent into a beaker, just enough to touch the chromatography paper.
- Place the paper in the beaker and allow the solvent to move up.
- Remove the paper before the solvent reaches the top and let it dry.
- Measure the distance travelled by the solvent.
- Measure the distance travelled by each ink spot.
- Calculate and compare Rf values for each ink spot.
Highlight: The importance of pure substances in chemistry is evident in chromatography, where the purity of a substance can be determined by the number of spots produced.
The page then describes tests for identifying four common gases:
Example: Test for hydrogen, oxygen, carbon dioxide, chlorine:
- Hydrogen: A burning splint at the opening of a test tube produces a rapid burn with a squeaky pop.
- Oxygen: A glowing splint relights in the presence of oxygen.
- Carbon Dioxide: Calcium hydroxide turns cloudy when shaken with carbon dioxide.
- Chlorine: Damp litmus paper is bleached white in the presence of chlorine.
These gas tests are crucial for identifying the products of chemical reactions and understanding the properties of different substances.
Vocabulary: Litmus paper is an indicator used to test the acidity or alkalinity of a solution, but in this context, it's used to detect the presence of chlorine through its bleaching effect.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
By signing up you accept Terms of Service and Privacy Policy
Understanding Pure Substances and Chromatography in Chemistry
This page introduces fundamental concepts in chemistry, focusing on the nature of pure substances and the technique of chromatography. It provides essential definitions and explanations crucial for understanding chemical composition and separation methods.
Definition: Pure substances contain only one type of element or compound and are in their natural state without any additions.
The page distinguishes between elements, compounds, and mixtures:
- Elements are composed of one type of atom.
- Compounds consist of two or more elements chemically joined together.
- Mixtures contain two or more elements or compounds that are not chemically bonded.
Vocabulary: Formulations are specific mixtures of compounds or substances that do not react together but produce a useful product for a particular function, such as deodorants or sunscreams.
The concept of chromatography is introduced as a method to separate mixtures of soluble substances. It involves two phases: mobile and stationary.
Highlight: In chromatography, pure substances produce a single spot, while impure substances result in two or more spots.
The page also explains the calculation of Rf values in chromatography:
Rf = distance travelled by substance / distance travelled by solvent
An illustration demonstrates the chromatography process, showing the separation of different colored inks on chromatography paper.
Example: A chromatography setup is shown with blue, green, yellow, and black ink spots separated on paper, with the solvent front reaching 10cm and one substance traveling 8cm.
We thought you’d never ask...
What is the Knowunity AI companion?
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.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
Can't find what you're looking for? Explore other subjects.
Students love us — and so will you.
4.9/5
App Store
4.8/5
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