Henderson-Hasselbalch equation | Acids and bases | AP Chemistry | Khan Academy

Keep going! Check out the next lesson and practice what you’re learning:
www.khanacademy.org/science/a...
One way to determine the pH of a buffer is by using the Henderson-Hasselbalch equation, which is pH = pKₐ + log([A⁻]/[HA]). In this equation, [HA] and [A⁻] refer to the equilibrium concentrations of the conjugate acid-base pair used to create the buffer solution. When [HA] = [A⁻], the solution pH is equal to the pKₐ of the acid. View more lessons or practice this subject at www.khanacademy.org/science/a...
Khan Academy is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We offer quizzes, questions, instructional videos, and articles on a range of academic subjects, including math, biology, chemistry, physics, history, economics, finance, grammar, preschool learning, and more. We provide teachers with tools and data so they can help their students develop the skills, habits, and mindsets for success in school and beyond. Khan Academy has been translated into dozens of languages, and 15 million people around the globe learn on Khan Academy every month. As a 501(c)(3) nonprofit organization, we would love your help!
Donate or volunteer today! Donate here: www.khanacademy.org/donate?ut...
Volunteer here: www.khanacademy.org/contribut...

[@Bedlaminhavana]

What an amazing, short concept video. Thank you!

[@n.k.3405]

THIS CHANNEL HAS BEEN UP FOR YEARS AND YET THEY'RE STILL POSTING VIDEOS... AHHHHHHHHHH

[@L_Lawliet1907]

They’re one of the biggest education platforms lol

[@yourlocalscribe948]

@@L_Lawliet1907 los santos

[@Protimonride]

Thank You. 🖤

[@divyasingh8147]

Such a good explanation I hve ever seen.

[@reginakatilo7032]

The lesson was cool... Thanks 😊

[@LINKJW]

thank you!

[@MrBoomington]

We actually had to prove this equation in the A-level exam. Yeah been 2 months now I kinda forgot it lol

[@randomvideos4296]

What exam board?

[@yaminaboub-jo2lb]

Thank you , this is really helpful

[@mothman663]

Thank God for Khan Academy...

[@subhamkarmakar3320]

Nice

[@azca.]

1:50 - How did you get the Ka value?

[@arthurchan4277]

google. it should be given if you need it on an exam.

[@reemalzubaidy6037]

U sound like Sheldon from Big Bang theory thank u

[@syedashobnam2573]

Or u can think it like this more conjugate base = more basic and higher pH, more acid= acidic solution less pH.

[@sapphireherkimere128]

What to do if there is a x10 on the pKa given to us while finding the pH, example is pKa = 1.28 x 10

[@thomasrimer1611]

That just means the pKa is 12.8 1.28*10=12.8, that is scientific notation

[@L_Lawliet1907]

Like the other guy said, it’s just scientific notation. Just move the decimal place to the right by one.

[@charliebrett7510]

At 3:50 I’m confused. I thought a weak acid partially dissociates into its ions in an equilibrium EQUALLY in a one to one ratio e.g CH3COOH->CH3COO- + H+. So the concentration of CH3COOH ALWAYS equals the conc of CH3COO- providing the volume of the buffer solution is constant. As m=cv c=m/v and so same moles/Same volume should give same conc for both CH3COOH and CH3COO- each time? Why is it 6 and 4? Can someone please explain?

[@dawsonlin5929]

Weak acids dissociate into their ions at an equilibrium based on their Ka value, so they don't always dissociate into a one-to-one ratio all the time. Furthermore, a buffer solution is formed by mixing a weak acid and its conjugate base, the concentrations of which are up to the scientist conducting the experiment. This buffer solution happens to have a ratio of 6 to 4, so he is calculating the pH in this particular scenario. Hope this helps!

[@charliebrett7510]

@@dawsonlin5929 so to recap, weak acids can dissociate into even amounts of their ions or uneven amounts of their ions based on their Ka. So in a calculation you would have to know the moles of the ions it dissociates into and the weak acid separately as there is rarely a 1:1 ratio. And thank you so much!

[@Logan-tg5we]

yet again another video I have wasted time watching that doesnt include how to calculate acid and base concentration for the equation. 7 min of my life I will never get back, thank you so much for not helping in any measurable way.

[@xinyi9118]

dont be a debby downer

[@micaelawillet8760]

you can use an ice table. There are other videos that explain how to find the h3o and oh concentrations.

[@eliasnakhle8534]

MATH

[@SD33396]

Hi sir