17.1 Buffers and Buffer pH Calculations | General Chemistry
Vložit
- čas přidán 30. 06. 2024
- Chad provides a comprehensive lesson on buffers and how to do buffer calculations. A buffer is a solution that resists changes in pH and is composed of a weak acid and its conjugate base. Chad discusses at length buffer solution preparation and the related buffer solution preparation calculations. He demonstrates that a buffer can be prepared with the proper ratio of any of the following three mixtures: weak acid / conjugate base, weak acid / strong base, or weak base / strong acid. A weak acid and its conjugate base should be mixed in approximately a 1:1 ratio. A weak acid and strong base should be mixed in approximately a 2:1 ratio. And a weak base and strong acid should be mixed in approximately a 2:1 ratio also. It is also shown that the buffer range is equal to pKa +/- 1, and that polyprotic acids therefore have multiple buffer ranges possible.
pH Calculations with buffers are also demonstrated using the Henderson-Hasselbalch equation. Chad derives the Henderson-Hasselbalch equation from the Ka expression and then uses it to show how to calculate the pH of a buffer solution. Finally, he also shows how to calculate the pH change of a buffer following the addition of strong acid or strong base.
I've embedded this playlist as a course on my website with all the lessons organized by chapter in a collapsible menu and much of the content from the study guide included on the page. Check this lesson out at www.chadsprep.com/chads-gener...
If you want all my study guides, quizzes, final exam reviews, and practice exams, check out my General Chemistry Master Course (free trial available) at www.chadsprep.com/genchem-you...
00:00 Lesson Introduction
00:26 What is a Buffer?
07:12 pKa and Buffer Range
14:47 Buffer Solution Preparation
21:34 Henderson-Hasselbalch Equation Derivation
26:37 How to Calculate the pH of a Buffer Solution
31:03 How to Calculate the Change in pH of a Buffer upon Addition of Strong Acid or Base
www.chadsprep.com/
courses.chadsprep.com/pages/p...
This is actually the most helpful video for this topic on youtube in my opinion. Thanks A TON!!
You're welcome - Thank you.
Omg thank you!!! This made the topic more clearer 😭😭😭 I don’t get why professors just vomit all the calculations on the board without thoroughly explaining it like you did😭. Thank you again man this really helped me!
Glad the channel is helping you - Happy Studying!
One of the most helpful channels I've seen. Please do organic chemistry 1 and 2 videos!
Thanks for the suggestion Emil :)
This guy is amazing. Thank you so much for making some of the most complicated concepts in gen chem straightforward and digestible.
You're very welcome!
I simply love love love this channel. Awesome work, Sir. Chad is the BEST.
Appreciate all the kind words - glad you found us!
I am halfway through this video yet I am already covinced that this is the best video about buffer on CZcams.
Thanks for saying so!
A big salute from Kenya .I love your way of teaching.
A big thanks from USA - Happy Studying!
You explain this to make it so easy. Was on organic chemistry tutor channel and understood nothing. Thank you so much
Glad you found the channel, Bridgette!
Starting my first semester as a Toxicology Biochem grad and I'm going in with only an undergrad degree in biology with no experience in organic or biochem, so I've a lot of catching up to do. These early sorts of concepts are novel to me, but the way you explain them is so easy to follow and helpful! Thank you so much for helping to take the stress out of things!
Welcome to the channel, Silver Atlas - glad it's helpful - Happy Studying!
One of the best chemistry mentor I have ever seen .
Thank you
bliss
neither my teacher's powerpoints nor chemistry libretexts are as concise as this video, i thought i wouldnt be sitting here for 45 minutes but this was just really helpful
Glad you found us!
Let's gooo! Feeling prepped for the next test!
Hope you ace it.
You are pedagogically gifted. Thanks for your videos.
Thank you and you are welcome
That is awesome! Much more easier than what our teacher taught us!
Glad it helps!
Really helpful video thank you! Can you further explain why it is necessary to use number of moles in calculations with limiting reactants rather than molarity?
Thanks mate, this video was better at teaching me about buffers than the 3 year chemistry degree i did.
You're welcome - Glad the video helped.
Got an exam tmrw, and this prob the best vid on buffers Thanks!!
Great to hear! Good luck on your exam
Thanks a lot men. That was helpful 👍
Very welcome
Good morning sir. Just I wakeup and open CZcams. Your videos only top on my you tube. Happy see to you sir 🙏💐💐💕
Great start to the day!
can you please do more exercises with no volume/ molarity given of a weak acid/base and need to find volume to titrate to a particular ph? ones with M and V given are too easy.
Was sacred... but after watching this, am in love.
Thank you sir🦋
Glad the video is helpful.
you are literally my savior.
Glad the channel is helping you.
i jut understood everything...thank you very much
Excellent - you're welcome
I saw that you had Pchem on your website for free
If you dont mind me asking
Is there a reason you dont upload them to your youtube channel?
Also will you ever plan on doing thermodynamics videos?
Ive been going through your acid-base titration and buffer videos and they are super helpful thanks
I have two questions though: Can you not have a WB:CA buffer? and how would you calculate SA:WB buffer?
Thanks again
Wb/ca buffer is the same as a wa/cb buffer. That's the DEFINITION OF A BUFFER!
As for SA/WB buffer yes. But it's in a 1:2 ratio. Half of the wb is neutralized. Reverting back to 1:1 of the two conjugates
Hello Chad, this was a great lesson. Definitely one of the harder concepts for me as I study for the MCAT. Question for you: As you state, a buffer is composed of a weak acid and its conjugate base or a weak base and its conjugate acid. Because a weak acid has a strong conjugate base and vice versa, could we say that a buffer is composed of a weak acid and a strong base and/or a weak base and a strong acid? Might have to rewatch some sections. I hope my question makes sense. Thanks for all your help
For example, around 22:45, you say something along the lines of, "you can use the Kb expression because you also have a weak acid's weak conjugate base." But I thought from previous lessons, that a weak acid will have a strong conjugate base and vice versa. Why is it different in this case?
saying its composed of a weak acid and a strong base would imply that it’s actually a strong base like NaOH, KOH, etc and vice versa. you’ll be safer just saying a weak acid/base and their conjugate base/acid
I recommend you to all my classmates!
Thank you!
You are amazing!
Thanks!
You deserve more subscribers
Thanks for saying so.
Amazing, super helpful
Glad to hear it, Tommy - thanks!
I wish lecture was this simple.
Glad you found the video helpful!
Amazing
Thanks!
the UCF chemistry department needs to start paying you. all the students use your videos over our prof's notes lmao
That's pretty incredible - Happy Studying to all the students!
Hi Professor Chad. I appreciate your content. Quick question, you mentioned common detractors @21:12 and state that 0.1M solution of HF and a 0.1M solution of NaOH won't make a buffer, but what if it's a 2:1 volume ratio in favor of HF ?
In this type of question you may be provided the volumes and concentrations of the solutions that are being mixed (what you are suggesting) or you may be provided with the final concentrations of the resulting solution (what I was referring to). You can typically tell the difference and the biggest clue is often whether or not volumes are provided. Hope this helps!
@@ChadsPrep …okay so if I understood you correctly, I would have a buffer in my scenario, but NOT in yours, right?
Exactly right!!! 😊
Thanks!@@ChadsPrep
Thank you!!!
You're welcome, bic!
thankyou so much
Very welcome.
I don't know how y'll be getting 3.2 because when I calculate I get 0.8325089. I am so frustrated I don't know what's wrong with my calculation
Brilliant 😊
Thank you very much.
thanks
You're welcome!
Thank youuuuuu
Youuuuuu're welcome!
Hello, can someone please solve this question for me, the pK value of an acid is equal to 5. What is the pH value of a 0.1 M solution of this acid?
I think the pH is 3.00 according to my calculations.
Cool!
Thanks!
God bless you
Thank you - to you as well.
I absolutely love that shirt!!!
Thanks!
You're Good 👍👍
Thank you.
we stan chad 🤴🏻
😄😄😄
I dont even know what to say. Thank you sir.
Most welcome.
Thank youuuu so much 🙏🙏🥰🥰
You’re very welcome, Ninou Nana! 😊
My GOAT🐐🐐🐐🐐
Happy Studying!
OK cool, it's the one of the my favorite word 😂😂😊😊☺️
😁 😁 😁
Hiii! Have you been born again?
Absolutely! And you?
😁
Self knowledge 😢
still I didn't understand 😅