Chemical reactions don't all happen at the same speed -... Show more
SociologySign 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
1 / 4
Understanding Rates of Reaction
Think of rate of reaction as the speedometer for chemical processes - it measures how quickly reactants disappear or products form. You'll calculate this using the formula: rate = change in concentration ÷ time, with units of mol dm⁻³ s⁻¹.
When you plot concentration against time, you'll get a distinctive curve that tells an important story. The graph starts steep because reactions are fastest at the beginning when there's loads of reactant available. As time goes on, the curve becomes less steep because reactants get used up.
Eventually, the line flattens into a plateau, showing the reaction has finished. This pattern appears in virtually every concentration-time graph you'll encounter, so recognising it is dead useful for your exams.
Quick Tip: The steeper the slope at any point, the faster the reaction is happening at that moment!
Factors That Speed Things Up
Four main factors control how fast reactions happen: concentration, temperature, catalyst presence, and surface area. Each one works by affecting how particles bump into each other during the reaction.
Collision theory explains why these factors matter so much. For a reaction to occur, particles must collide with the correct orientation and have energy greater than the activation energy. It's like trying to unlock a door - you need the right key (orientation) and enough force to turn it (energy).
Concentration has a massive impact on reaction rates. Higher concentration means more particles crammed into the same space, leading to more frequent successful collisions and a faster reaction. Lower concentration gives you fewer particles, fewer collisions, and a slower rate.
Remember: More particles = more crashes = faster reactions!
Measuring Gas Production
One brilliant way to monitor reaction rates is by collecting gas using simple lab equipment. You'll need a conical flask for your reaction mixture, connected to a gas syringe via a delivery tube, with a bung sealing everything up.
The method is straightforward: measure the volume of gas produced at regular time intervals using your stopwatch. This gives you real-time data about how fast your reaction is progressing.
When plotting your results, follow these essential graph rules: start at the origin, draw smooth curved lines of best fit, and use sensible scale intervals that fill the whole graph space. Mark each data point with an 'x' and ensure your axes are properly labelled.
Pro Tip: Using the full graph space makes it much easier to read accurate values and spot trends in your data!
Monitoring by Mass Loss
Mass loss provides another excellent method for tracking reaction rates, especially when gases escape from your reaction mixture. As the reaction proceeds and gas bubbles away, the total mass of your setup decreases over time.
This technique works particularly well for reactions producing carbon dioxide, hydrogen, or other gases that can escape. You'll plot mass against time to create graphs that show the same characteristic curve pattern as concentration-time graphs.
The beauty of this method is its simplicity - just pop your reaction vessel on a balance and record the mass at regular intervals. The faster the mass drops, the quicker your reaction is happening.
Key Point: Mass loss and gas collection often give you the same information, so choose the method that works best for your specific reaction!
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.
Most popular content: Reaction Rate
Most popular content in Chemistry
Most popular content
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
10.1 - Understanding Reaction Rates
Chemical reactions don't all happen at the same speed - some are lightning fast whilst others take ages to complete. Understanding rates of reactionis crucial for your chemistry exams and helps explain everything from why food spoils to how... Show more
Understanding Rates of Reaction
Think of rate of reaction as the speedometer for chemical processes - it measures how quickly reactants disappear or products form. You'll calculate this using the formula: rate = change in concentration ÷ time, with units of mol dm⁻³ s⁻¹.
When you plot concentration against time, you'll get a distinctive curve that tells an important story. The graph starts steep because reactions are fastest at the beginning when there's loads of reactant available. As time goes on, the curve becomes less steep because reactants get used up.
Eventually, the line flattens into a plateau, showing the reaction has finished. This pattern appears in virtually every concentration-time graph you'll encounter, so recognising it is dead useful for your exams.
Quick Tip: The steeper the slope at any point, the faster the reaction is happening at that moment!
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
Factors That Speed Things Up
Four main factors control how fast reactions happen: concentration, temperature, catalyst presence, and surface area. Each one works by affecting how particles bump into each other during the reaction.
Collision theory explains why these factors matter so much. For a reaction to occur, particles must collide with the correct orientation and have energy greater than the activation energy. It's like trying to unlock a door - you need the right key (orientation) and enough force to turn it (energy).
Concentration has a massive impact on reaction rates. Higher concentration means more particles crammed into the same space, leading to more frequent successful collisions and a faster reaction. Lower concentration gives you fewer particles, fewer collisions, and a slower rate.
Remember: More particles = more crashes = faster reactions!
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
Measuring Gas Production
One brilliant way to monitor reaction rates is by collecting gas using simple lab equipment. You'll need a conical flask for your reaction mixture, connected to a gas syringe via a delivery tube, with a bung sealing everything up.
The method is straightforward: measure the volume of gas produced at regular time intervals using your stopwatch. This gives you real-time data about how fast your reaction is progressing.
When plotting your results, follow these essential graph rules: start at the origin, draw smooth curved lines of best fit, and use sensible scale intervals that fill the whole graph space. Mark each data point with an 'x' and ensure your axes are properly labelled.
Pro Tip: Using the full graph space makes it much easier to read accurate values and spot trends in your data!
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
Monitoring by Mass Loss
Mass loss provides another excellent method for tracking reaction rates, especially when gases escape from your reaction mixture. As the reaction proceeds and gas bubbles away, the total mass of your setup decreases over time.
This technique works particularly well for reactions producing carbon dioxide, hydrogen, or other gases that can escape. You'll plot mass against time to create graphs that show the same characteristic curve pattern as concentration-time graphs.
The beauty of this method is its simplicity - just pop your reaction vessel on a balance and record the mass at regular intervals. The faster the mass drops, the quicker your reaction is happening.
Key Point: Mass loss and gas collection often give you the same information, so choose the method that works best for your specific reaction!
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.
4
Smart Tools NEW
Transform this note into: ✓ 50+ Practice Questions ✓ Interactive Flashcards ✓ Full Mock Exam ✓ Essay Outlines
Mock Exam
Quiz
Flashcards
Essay
Similar content
Measurements
You will be able to learn how do we measure in science.
Chemistry9th
Understanding Reaction Rates
Explore key concepts of reaction rates, including collision theory, factors affecting reaction speed, and the role of catalysts. This summary covers essential exam questions and explanations related to reaction kinetics, temperature effects, and chemical equilibrium. Ideal for students preparing for chemistry assessments.
Chemistry11
Ernest Rutherford - atom model presentation pt. 4
Learn about Ernest Rutherford's groundbreaking experiment that confirmed the presence of positive and negative charges within atoms and led to the discovery of the atomic nucleus.
Chemistry10th
Density & Percent Error
Calculate percent error and density
Chemistry9th
Atomic Number, Metals and Elements in the Periodic Table
Learn about the reactivity and properties of metals, alkali metals, alkaline earth metals, and transition metals in the periodic table.
ChemistryCollege
Chemistry: Branches of Chemistry
An introduction to chemistry including the different branches of chemistry.
Chemistry10th
Most popular content: Reaction Rate
Most popular content in Chemistry
Most popular content
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