Introduction to pH, pOH, and pKw

Autoionization of water into hydronium and hydroxide ions. pH, pOH, and pKa.
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No MCAt just regular ol biology 🧬 online at that

[@Xiek11]

Is this really how simple this pH pOH thing is? My lecturer explained this in a really complicated way. Thanks a million. Great work!

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this is amazing! i was having so much trouble understanding my chem stuff, and in one video you've made it crystal clear for me. i went from feeling overwhelmed and almost withdrawing from the course to understanding it well enough to explain to classmates! thank you!!!

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Giulia Depo

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8:19 of off.. I ain't off untill I watch this video fills my heart.😊

[@pklmbyers]

SoI have taken years of chemistry and NO ONE ever explained what 'p' was! Thank you!

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Thank you so much! Your explanations are so clear and easy to understand. You make super chemistry fun! :D

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I’m in biology why am I doing chemistry??

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This video was really helpful. You should have a comment section on your website so that students can give you feedback. Thank you!

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You're cute.

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[@dramaticsloth3012]

Yes that made perfect sense, however is it just a temporary bond before the hydrogen ion moves onto another oxygen (not sure how it would since the charges attract) because an oxygen can't have more than two bonds usually. If i remember right it is dependent on what angle the bond is and therefore it can only hold a certain number, for instance i think water is held at 107.5 degrees .......

[@r00bii]

@splitecho Oh, Sweet! I'm using these videos right now for GAMSAT (Australian MCAT).

[@paulceltics]

very helpful. this is something that is going to save my grade

[@BackCountrySR]

@The19thKey M represents Molarity, and the molarity is found by Moles/Liters of solvent, in this case water.

[@dariusfullmer171]

If we consider H2O to be aqueous it would be included in the equilibrium. Of course it is not included in Kw, so it should be referred to as a liquid, not aqueous.

[@Dnj1zzzz]

+Darius Fullmer Yep, was just about to write this; essentially this is screwing up a lot of stuff lol

[@4635683763]

ooooooooooh my wooooooooooooord! absolutely love this vid's. going to save my (academic) career! thank you so much! :D (grinning like a boss)

[@dydx6584]

THANK YOU SO MUCH. I WAS SO LOST WITH ALL THE EQUATIONS AND EVERTHING

[@necaccamo]

@The19thKey g/liter= density to get the molarity(M) you need to convert grams to moles. Molarity= mol/volume Volume= liters or millimoles/milliliters. =)

[@navdeep_singh_suri]

You made this chapter easy...thanks!

[@terradan2013]

Thank you for explaining, in simple terms, what all this means.

[@christyc463]

@azndude3600 i don't know for sure, but since no one else has answered you... i think it's just something that happens from time to time randomly. atoms and their components are always moving (electrons, in particular) and occasionally, they move in ways that are very unusual, but not impossible..

[@osama105]

you are soooo freaking amazing. like everything just makes sense to me now.

[@MattiasJohnson]

When he said that there almost always a probablility of anything to happen it got me thinking, couldn't it be a scenario where a watermolecule loses both of it's hydrogenatoms simultaneously, each one of them to different watermolecules? So like this happends: 3H2O ---> 2H3O + O ???

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it shows you up the top of this page on the right hand side

[@abcdefgh-fb5ny]

I wish my highschool teachers had taught me the concept like you did, instead of just giving us the formulas and letting us go figure out the problems ourselves. Then I wouldn’t have to re-study an 11th GRADE TOPIC

[@RikaShion]

Sir, you have just offered a big big help !!!

[@joelarthurng1530]

thank you khan really helped me understood the topic

[@Jfrancis221]

We should use (l) for H2O indicating it is a pure liquid, not (aq)

[@Rusty2891]

@WarpFieldTheorist I received an email saying and I quote " And yet the protons and hydroxide ions are certainly part of an aqueous solution, in much the same way as sodium and chlorine ions can be part of an aqueous solution. When you study chemistry at university you discover that there are all kinds of weird structures floating around which are made of many 'water' units and ions. It is perfectly acceptable to refer to this swamp as an aqueous solution."

[@azndude3600]

@christyc463 I think I found out. I think its a form of intermolecular forces and in this case its ion-dipole attraction.

[@dogsshit76]

azndude3600

[@alvaro2416]

Thank you very much!! i was soo confused. Now i understand how this work! yay!!

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How many subscribers he had at that time??

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Me

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i hate my high school teacher more than everyone that pisses me in the past

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[@mvadim25]

@The19thKey Molarity is mole/liter

[@arstgkneio]

Damn, you leave no room for ambiguity. I like that.

[@Alfietto92]

Flawless explanation =D

[@lourdeslopezdiaz9881]

Gracias por los subtítulos!!!

[@efisgpr]

Sabías que todo el contenido de Khan academy.org está disponible en español también? Bueno, en interfaz español, por lo menos....y que tienen otro canal acá en KZbin que se llama "Khan academy en español" o algo muy parecido? Suerte, Alex

[@ahmadkhaled9072]

imagine watching this vid 5 years ago..

[@digiconvalley]

jazakaAllahu khairun

[@Janac]

@WarpFieldTheorist haha but rusty is completely right. khan made an innocent mistake, you cannot have aqueous water (which suggests water is dissolved in water). Thanks for point it out rusty, i don't feel that your comments are "bashing with education".

[@Rusty2891]

@WarpFieldTheorist Water is not aqueous. When the word water is used in Chemistry it means H2O. There are no salts, no dissolved compounds or a 'swamp' of materials in this. If there was, it wouldn't be water in its purest form, and this purest form is what is being referred to here. And by the way, I am at University working my way through a masters degree and never before have I seen H2O (aq).

[@madlenlika4695]

Thank u soo much!!!u really helped me with this video.

[@lyssss09]

Can u come here in australia and be my highschool chemistry teacher?:)) Thanks so much for this.. I understand it more that when my teacher was teaching us that:))

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Whoever you are, someday I want to meet you and shake your hand. There's nothing you can't put in understandable terms.

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you're amazing.

[@rawdonwaller]

Pedantic though it may be, does H2O's subscript (l) stand for liquid? I thought that aqueous phase means that the molecule or ion is surrounded by water molecules, in which case water molecules themselves are 'in' liquid phase (because it doesn't make too much sense t think of water molecules solvating themselves)? Of course, this is a superb video, and I may be wrong anyway.

[@Eludinium]

So does this mean that water IS wet?

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[@murdoc20000]

why is the option to increase the play speed removed?

[@aussietro]

Thats a great score! What else did you do?

[@dogsshit76]

Austin Friswold

[@rawdonwaller]

@TheYo12343 Maybe 'puissance', as in puissance de Hydrogen? 'Puissance' is the French term for 'power.'

[@sibtiali802]

16:30....oooo now i know what pH actually means!

[@NomsNomsNomsNoms]

great :) didn't notice any mention of pKa? thanks you :)

[@agent475816]

If Hydroxide and Hydronium are formed, won't they just collide together and turn back into water. Doesn't make sense, unless they are surrounded by water molecules. the OH- is surrounded by water molecules on the hydrogen side and the H3O+ is surrounded by water molecules on the oxygen side. If that's not the case, then they would attract each other right?

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Thank you for putting these great videos out.

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Will those neon colours affect the eye

[@amadeus_music]

@khanacademy you said at 10:00 that M = mol/l. but isn't M = g/mol??

[@Poochester]

you are amazing.

[@hardikkardam6116]

thanks , u r the best !

[@mrcrumpet123]

you are a god

[@dramaticsloth3012]

i like the video, however how can there be a hydronium ion when oxygen has a valency of 2?

[@arousedsquirrel2429]

Shouldn't water be (l) instead of (aq)?

[@TheAceblogger]

only pure water can be (l). (aq) water means there are impurities in it.

[@arousedsquirrel2429]

***** There should be pure water on the left side of the equation. aq means dissolved in water. Water can't be dissolved in water.

[@marija347]

It can

[@heeheehoppsies]

Thankyou so so so so so so so so so so so so so so so so so so so so so so so so so so so so so so much

[@Rusty2891]

@northlight72 Have you actually ever ready anything I put? I simply pointed out one mistake, and one other way of saying something. Your saying I am not helpful when people have said that I have been. I mentioned my masters degree as someone said that 'il understand better at uni', so i mentioned that i was already at uni and havent heard water as aqueous. I've never attacked the Khan Academy, even when he made a mistake. His videos are fantastic and helpful. And thanks for the career info :)

[@lucasfelipedesousa8006]

p stands for "Potentia Hydrogenia" (Potential Hydrogene Force)

[@BareClause]

isnt h20 mean 20s and a 1 h because of the coefficient

[@Rusty2891]

@WarpFieldTheorist Your a PhD student (guessing Chemistry) and you think 2H2O(l) ---> H3O+(aq) + OH-(aq) is wrong? I actually went out of my way to visit my Acids and Base lecturer to ask about this and he said that H2O is a liquid. What did I say that was critising the video? I pointed out 1 error and thats it. And calling me a Troll...well the less said about that the better.

[@Phaze252]

Technically it should be (l) because the (aq) is as he said redundant and the OH- is called OH instead of HO because of tradition.

[@1xtra299]

@WarpFieldTheorist & @northlight72: do you guys have any links that prove what youre saying? im all confused now... even my professor says that H20 should be a liquid

[@Madietastic]

OH MY GOD.....Thank you so much...

[@Rusty2891]

H3O is known as a hydroxonium ion aswell. Also H2O is not aqueous, it is a liquid. You can't dissolve water in water.

[@digiconvalley]

u r the best

[@abdulsami3730]

I still didn't understand the reason why he took the concentration of reactant (H2O) as 1. I would appreciate if someone could explain that.

[@ffaiq]

it should be 2h20(l) and (l) isnt included in kw

[@dogsshit76]

Abdul Sami

[@nas9095]

Thank you so much!

[@KalimaShaktide]

The link is broken...where is this video on the main site?

[@azndude3600]

Why would water form hydronium? I don't understand it. Oxygen is already happy with its 8 electrons. Why would it get another proton?

[@calmario117]

I finally understand this!!!

[@musicajourney1643]

Thanks!

[@lysafae]

@iusting Oh, congrats! :D. I hope one day, I'll be topping my class too. :D

[@TheSadPaki]

Did you do that?what did it cost? You:Everything!😂

[@pepteamsergi09]

How do you get those concentrations? or where do those concentratons come from? what's the math behind it? thank you.. still the Video is 4.5 stars

[@AshaunaByrum]

Where is the next video to this series??

[@CarterEnt-x3d]

Doesn’t the “P” in pH stand for potential?

[@ahmadabdullah8168]

Yes, it does 🙂.

[@crashonthehumble]

nice work

[@BrandonPentz]

some can, just no one pays attention to what there saying, whereas, in this video, you do

[@chrysovalantistasiopoulos9987]

because the density of pure water is 1 gr/ml , and the molar mass of water is 18 gr/mol in 1 liter which is 1000gr the number of moles is 1000gr/18gr/mole = 55.55mole per liter, that is a constant value of the concentration of the water, so Kw=K*55.55M =K*[H2O] , this is the reason you never writing the concentration of the pure water in the denominator of the fraction of equilibrium constant . IT has nothing to do with probabilities !!!!!!!

[@lysafae]

@Mrgamer4 Haha. Same here!

[@comedianmalyka2646]

this video came out when i was 8

[@ZahdShah]

I was 10 or something lol

[@sciencenerd7639]

thank you