16.5 pH Calculations for Weak Acids and Bases | General Chemistry
Вставка
- Опубліковано 5 сер 2024
- Chad provides a comprehensive lesson on how to calculate the pH for solutions of Strong Acids or Strong Bases.
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 Introduction to pH Calculations for Weak Acids
02:25 Ka and Acid Strength
06:52 Calculating pH of Weak Acids
15:35 Shortcut for Calculating pH of Weak Acids
17:45 Calculating Ka from pH
20:55 Calculating Percent Ionization of a Weak Acid
22:42 Kb and Base Strength
26:07 KaKb=Kw
29:02 Calculating pH of Weak Bases
32:35 Shortcut for Calculating pH of Weak Bases
33:00 Calculating Kb from pH
www.chadsprep.com/
courses.chadsprep.com/pages/p...
I think the Kb value should be around 2.5e-7 for the last question. Multiple people have commented the same answer vs his answer.
Just checked what Chad did he plugged the values as follows (10^-3.8^2)/(0.1-10^-3.8), you see what he did wrong the correct way is (10^-3.8)^2/(0.1-10^-3.8)
I agree, when Chat GPT and Chad gets the wrong answer you know your in to deep.
I cannot express how amazing all of your videos are! I went from barely scraping by to getting a 90% on my last exam. :) Thank you ❤
Great to hear!
I dont get why your videos don't have more thumbs ups and views. You have saved me this semester in Gen Chem 2! Thanks Chad!
You're welcome, Brooke - glad the channel is helping so much!
kb on last example is 2.5x10^-7 to confirm for those confused. :)
we all make mistakes.
I tutor for general chemistry and I mainly use your videos as a reference! God bless your channel and family!!
Excellent and Thank You!
absolute chad
Another short way of finding pH of weak acids is: "pH=1/2 (pKa - log[HA]i)". Following this method I got pH of 2.875 (round up to 2.9) for the first example. The same thing goes for pOH; substituting pKa for pKb and [HA]i for [B]i respectively. Just a method I was taught, I thought it would be interesting to share. Love your videos, Chad! You helped me immensely
yup he's got rounding errors.
greatest youtube teacher all time
Wow - that's high praise - thank you!
You videos are so easy to understand, you are the best.
Thanks very much.
Thank you so much for this good explanation!!! I finally understand it
Excellent!
Thank you very much Chad, I love how simple you make everything man ❤
You're welcome and Thank you.
Your videos are awesome, and I'm so grateful for you help! Just a note though, I ran the numbers several times (even just using the decimals instead of scientific notation) and kept getting 1.78 x 10^-5 for Kb. Is there a chance your calculator didn't format your entry correctly on the last problem in the video?
Bro living up to his name.
Glad you like the channel!
I'm happy to find your channel. I study at İzmir Institute of Technology in Türkiye and my department is chemistry. Our lessons' is 100% english. But my english skills is not enough to understand the classes. But your videos helps to me understand very well. (sometimes speed: 0.75x) Thank you.
Glad you found the channel and that it is helping you - Happy Studying!
Hi Chad. at 35:15 when calculating Kb with that formula I get different answer. (2.5e-7 instead of 3.6e14).
Can you help?
i also got the same value
Yea i got the same answer too, I think he may have made a mistake, rare, but i think it might have happend
Yeah I got the same answer
me too
Just checked what Chad did he plugged the values as follows (10^-3.8^2)/(0.1-10^-3.8), you see what he did wrong the correct way is (10^-3.8)^2/(0.1-10^-3.8)
Hola, Chad, sólo te escribo para agradecerte por tus vídeos, porque, gracias a eso, fuí aceptado en la maestría.
Espero te encuentres bien y te deseo todo el éxito y la salud del mundo.
Te envío un abrazo desde México.
Awesome! Congratulations! And you are most welcome! And best wishes in the masters program and beyond! 🎓
Nice teaching way 💕💕
Thanks!
saving lives out here
Saving grades maybe, but hopefully just saving time!😉
GAINED A SUB BECAUSE OF THAT SHIRT CHAD.
[ THANKS FOR THIS PRODUCTIVE LESSON]😍
Thank you and welcome to the channel!
you are the best
Thank you
Hello Chad! Thank you so much for these videos - they help tremendously! For this one, at around 35min, my calculator keeps displaying an error message each time I try to calculate with 10^-3.8. I've tried other variations of this but continue to get the error message. Are you typing in something different?
My calculator just doesn't want to work with decimals in exponents :/
Figured out my mistake. Didn't realize 10^-3.8 was the inverse of log! :)
You’re sooooo not a “Chad”. Thanks Chad!!! 🎉
You're welcome!
Under what circumstances can you feel confident using the (Sq root(Ka[HA]i) shortcut? I know K must be 100x less than your initial concentration, but must the products also have the same molar concentration?
Sir, need coordination chemistry, statistical thermodynamics, group theory, and quantum chemistry video s... 😊
Thanks for the feedback Chemistry wide - noted :)
@@ChadsPrep ok ok sir.. 💐
When I pluged the values of (10^-3.8)^2/(.1-10^-3.8) my value equaled 2.51 * 10^-7.
Where did the 3.6*10^-14 come from, what step am I missing/forgetting?
Please and thank you Chad
same. i thought iw as going insane.
Just checked what Chad did he plugged the values as follows (10^-3.8^2)/(0.1-10^-3.8), you see what he did wrong the correct way is (10^-3.8)^2/(0.1-10^-3.8)
GOD BLESS YOU! THE LORD GOD of Heaven Bless you and keep you, and make His face shine upon you and be gracious unto yiu, and give you His peace, and His countenance.
He does every day - and to you as well!