Vapor pressure | States of matter and intermolecular forces | Chemistry | Khan Academy

[@vishalmali921]

Finally ... I got what vapor pressure really is. Thanks Sal.

[@inezraharjo]

"if you leave water outside, it will evaporates, even though, hopefully, in your place, is below the boiling point" LOLOL

[@KartikeSingh-sx7tg]

Evaporation and boiling point are diff but the guy can't explain it properly

[@dragooner4]

this answered my great questions. It's like one of those questions that you had when you were a child and then suddenly when you learn about it it all makes sense. This video answered that question for me.

[@limesther7000]

I was literally hunting around everywhere to find a good explanation of vapor pressure. FINALLY I understood it!!! Thank you so much Sal, half of my educational career credits to Khan Academy

[@tahiraprogga7367]

Half?

[@anoelst]

Khan for president!

[@benjaminion.]

+tonio noel of?

[@Mae-nw6cv]

Benji COC/CR of teaching

[@dudemanismadcool]

got away with two fluids courses and currently in my third thinking I understood vapor pressure only to find out now I didn't. Legendary explanation thanks mate.

[@Tasniaaaaaaaa]

Sal, thanks for doing what my teacher apparently doesnt know how to do-teach.

[@zitscx886]

Don't let the teacher lead you. Let your curiosity lead you.

[@kevinikeda8394]

You replied to an 8 year old comment, nice

[@atiyagardezi7918]

Hello guys

[@smellyfish4699]

Hello

[@maahinsethi8330]

hello

[@Diminisch]

Studying for MCAT, this video really helped me with this subject, Thank You!

[@BBLitchi]

Thank you. I finally understood what vapor pressure is. Believe it or not, I was struggling to understand the concept of vapor pressure for 3 years until I came across your video. Thank you again!

[@shardaejoseph6516]

this was extremely helpful thank you Sal. i don't even have to read my notes. lol

[@j9312]

seriously you'v got some serious skills with a mouse dude.

[@yuudesu]

You alive mate?

[@kevinikeda8394]

They’re all dead no

[@atulanand1337]

@@yuudesu Why do people always think that commenters of old comment will be dead? If he/she was of roughly 20 years (considering the topic being taught in this video), that person would be about 30 (far from the average life expectancy).

[@yuudesu]

@@atulanand1337 bruh that's just a joke ..don't take it seriously

[@Buildingscienceacademy]

3:15. Is there a name for this yellow line? (The point where there’s enough to escape)

[@YouWM]

I'm a student of Technical Chemistry and know all those concepts, but those videos are so unbelievably intuitive and well explained! Congratulations!

[@MAWAnubis]

Are you alive?

[@AdityaMishra-vy8re]

Thank you so so much ... I could finally see all the pieces coming together.... U literally made me cry.... Beautiful explanation😍😍😆😆

[@Livingbeing01]

I LOVE KHAN ACADEMY

[@Khyatii_Verma]

This was the topic none of my 3 chemistry teachers could teach me and sal Khan taught me in just 18 minutes.

[@evagao2331]

Really good explanation. Thank you very much for making these videos!

[@okccitizen4400]

Thank you for what you do

[@NilanjanaLodh]

thank u sooooo much! u made it a lot more clear!earlier i was just confused about the relation b/w bp and vp .and i really love ur teaching style!

[@marcelo497]

The inability of my chem teacher to explain this brought me here, but at least now I can say that I understand it. Thanks fella

[@deepprakash4841]

thanks a lot!!!!!! just understood the concept! thanks a lot...............

[@VistarMonei]

So much clearer than the notes my Chemistry teacher gave me... I'll be sure to watch these videos before doing my homework for next time, too!

[@Piou_le_petit_ours]

Nicely explained. Detail but interesting, the amount of energy on the particles follow a maxwell boltzmann distribution and not a normal distribution. But same idea, some have anough energy to break out, while most dont (during evaporation).

[@curtpiazza1688]

Great explanation of the graphs! 😅 🎉

[@MrPaolosio]

Brilliant. Crystal clear. Thanks :)

[@anton_s1]

This video is amazing. Everything makes so much sense now. You are a hero!

[@vishalvala4788]

Thanks for uploading.

[@gauravGupta-bk2sw]

Only patience 🙏 can help someone watch this lecture, I'm giving up 😔 too much info god 🥴😮 just not in d mood tday Too lazyy to write any..thi..ng...elsee....aah!!

[@MrCordezzz]

Thank you so much for the time you have put into these videos. They are really helpful.

[@virupannamedikinal]

Really helped me a lot

[@robjows]

I don't understand how the vapour could push the atmosphere if its pressure merely equals atmospheric pressure, wouldn't it need to exceed atmospheric pressure to move it?

[@espejitos15]

Very well explained.Thank you!

[@hitendraverma5079]

nice information man...........................

[@frogspasm]

Great videos a lot clearer than my textbook. These videos have helped me a lot. Yhank you very much

[@YoungKiIIaX]

The only problem with how you teach is that sometimes your words just jump.

[@mybirjitthangjam7388]

Thankuu very much

[@curiouskiddo6885]

@ 0:42 shouldn't it be heat of vaporization? Where am I going wrong?

[@MrCooldude4172]

Thank you so much you really helped me for year 1 Uni.

[@wxh2018]

At around 13:00 So when the vapour pressure is equal to the ATM does that mean that total pressure = ATM + vapour pressure?

[@atiyagardezi7918]

Yea

[@rickmcn1986]

No. I think he is missing out the idea of partial pressure. If we have air and vapour, the vapour pressure is the partial pressure of the vapour above the liquid. At boiling the pressure just above the liquid will still be 1atm, but will consist entirely of vapour coming off the surface - the air will be pushed upwards.

[@wxh2018]

@@rickmcn1986 Hahhaa thanks. 4 years ago wow, I've graduated engineering now. Wow xD

[@CallofDutyNOOB1]

so does a high vapor pressure also means that this liquid will have a low boiling tempreature?

[@mclarenjoao1049]

Indeed

[@expoberries]

So, if the equilibrium vapor pressure is set to a higher temperature, and consequently, the rate of evaporation increases, then the rate of condensation also increases, correct? Because if each happens at in equilibrium, than the rates should increase and decrease along with one another? I'm not entirely sure, but the video did provide very good insight on the matter.

[@Be1smaht]

congrats!!!! what u use for veral?

[@bellacanque9566]

Thanks Sal ☺️

[@dill_lift]

Thank you so much! I have a test in 30 mins and this video helped a lot!!! Keep up the great work! You explain like a beast :p!

[@smitrib]

So does water or gasoline have stronger IMFs? Water is polar, while gasoline is nonpolar.

[@techfive7202]

I'll take your word for it. Thank you

[@jullysrandomvlog4702]

that was a great help .............thanks a lot!!!

[@rickmcn1986]

I don't know if this can be explained like this without the concept of partial pressure. Vapour pressure of a liquid equals the partial pressure of the vapour just above the surface at equilibrium. The pressure itself just above a liquid open to the atmosphere is going to remain at about 1atm no matter what. When you boil the water the partial pressure of the vapour just above the liquid rises to 1atm.

[@nitinchetla9970]

10 videos later and finally someone explains why vapor pressure ends up pointing "up"

[@84salute]

Best video on Vapor pressure so far!

[@maahinsethi8330]

11 yrs old

[@maahinsethi8330]

comment

[@kenseow005]

Thanks for the great explanation. One thing taught by my lecturer confused me. Is there something called "maximum vapour pressure" ? Or can I say the maximum vapour pressure can be achieved is 1atm? Since when they reached 1atm the solution will start boiling.

[@Aikman94]

Khan, YOU ROCK! THANK YOU!!!

[@DaveHowardvideos]

This is great information and very well explained.

[@cayamb]

KHAN IS THE BEST !

[@satuwesterholm5058]

Thank you so much!

[@meylinmuniz4510]

To determine vapor pressure do we look at how strong the intermolecular forces are or the concentration of solute?

[@hdkwon64]

best video thanks

[@bublzmcbublin8317]

When you mention overcoming the heat of fusion @.41 into the Video, shouldn't it be the heat of Vaporization, since you already mentioned we are starting with liquid.

[@rajanparthipanbalaraman6736]

சிறப்பு

[@crazychemistacademy979]

Incredible

[@farzee]

please explain separation in reciprocating pumps and how it relates to this lecture on vapor pressure..can you please make a video on it..if you already have a video on it..plz reply with the link here..thanku so much for this video here

[@arwaaomran9093]

you said that at the point when the vapour pressure is equal to the atm. pressure we reach the boiling point of the fluid then on the chart of different fluids you said that propane will boil at 20 degree celesius as its vapour pressure is much higher than the atm. pressure ?? so do you mean that boiling point will be at the point of equilibrium or higher ? and also why does propane molecules continued to evaporate and exerted much higher vapour pressure than the atmoshpheric pressure ?

[@oXmichikoXo]

Thanks for the lecture!

[@lavanzentgraf]

The atmospheric pressure of a butane lighter is 3.5 the earth normal atmospheric pressure

[@5gallonsofwater495]

Holy, as soon as he said heat of fusion I suddenly understood everything. Thanks from an electric engineer

[@sheilavicentedasilva3145]

Wow ...👏👏👏

[@kevluv93]

I won't lie to you Sal, if it weren't for you I would have probably failed college. Thank you

[@HimanshuSharma-kq7kh]

What is the relation of food cooking in a pressure cooker with vapour pressure (decreses, increases & external internal)?

[@larissashen4874]

Very interesting facts about how matter is always changing. It really helps me understand just how weird living things are for trying and managing to keep things stable.

[@engineerdr]

i didnt get how a greater vapor pressure can enhance the evaporation rate.plz help

[@16velvet]

thanks!

[@HimanshuSharma-kq7kh]

When (1)Vapour pressure atmospheric pressure=====??????????

[@iaminvisible5659]

Appreciate it!

[@chinmaykumarpatra3785]

really understood.

[@gdogvibes1]

perfect.

[@kisskisskiss121212]

It is spelled vapor in America...

[@txfury4753]

Ohhh now I finally get it

[@BraulioCLBF]

The best video!

[@flydiezz]

Thank you for the lecture, but i have a question that is bugging me and i would like to ask my fellow viewers - Is vapor pressure always in equilibrium? If not, can vapor pressure surpass that equilibrium?

[@hussam023]

8:00, its vapour pressure not vapor pressure.......a gr8 video, understood everything. :D

[@cousin13pro]

wow thanks man

[@atharvat223]

really good video

[@KUVVAlTi]

Can u start all ove agine? cuz i havent understod anything

[@NSBeverything]

whenever water or any liquid evaporates to atmosphere its temp reduces why? is it becoz the molecules possessing higher KE is escaped and overall KE of liquid is reduced? and why dont temp reduces when container is closed? still few molecules does escape from liquid..

[@clchoate24]

Looks like John Madden's attempt at showing vapor pressure haha

[@Adriancatdad]

So in vacuum, water wouldn't boil?

[@anamikavats2613]

Maiar The dreamer it would boil without you differing it's temperature .

[@MafiaDiesel]

fatal mistake, atm goes down as you go higher in altitude, not up

[@engineerdr]

nice video sir.a cyber student from Pakistan

[@madara.n]

I just don't know why I'm not feeling enthusiastic about my studies... All of a sudden there's this urge telling me to study and when I take the book into my hands, its gone... I wanna make learning interesting for me.

[@yuudesu]

Same mate, especially in this pandemic ;(

[@lets_get_creative]

if water is kept open for ten years ,then it will disappear after 10 years

[@shaikqayum9699]

i have good standard problem

[@omerzaman2373]

Lets say I have 10 molecules of water at room temperature (Supose). They collide and 2 of them gain enough energy to evaporate. Doesn't this mean that the 8 have less energy now and have less energy now. So "I THINK!" that they will get energy from surroundings and get back at room temperature and in the same way 2 will evaporate. Now lets say all evaporated and 2 left. Now they collide and 1 evaporates and 1 is left at room temperature. Will that one last molecule evaporate? If so how. Is this assumption that I made logical? Is there some quantity of water that will never evaporate from a glass?

[@joeb8345]

Omer Zaman yes, when the vaporized molecules leave they take some energy from the liquid with it (hence why putting a drop of water on your hand feels cold, the water is "leaving" your hand and taking energy in the form of heat with it). The liquid will gain it's energy back from the surrounding environment, temperature permitting. -Joe. ChemE major

[@kazsiddique1]

is this guy the voice of one of the droids in interstella?

[@pradhikasotiya4207]

does anything which is a matter have some vapour pressure? as in solid,liquid,....!!!

[@rickmcn1986]

Solids have extremely small vapour pressures, yes.

[@patrickjohnson4648]

looks like an extremely complicated playbook

[@kinkitan2835]

my mind suddenly pops out a question. How do we know the molecules in liquid? can we see it by any instrument ???????

[@logickedmazimoon6001]

Microscope

[@gauravGupta-bk2sw]

You dont need to count individual molecules 😂 just see the mass of the substance, use a little bit of periodic table, the avogadro's no. and figure out the moles using the molecular mass, you'll get the no. of molecules using mole concept and some Math! 🎉❤

[@gauravGupta-bk2sw]

​@@logickedmazimoon6001🥴🙏👏🤣 very funny

[@logickedmazimoon6001]

@@gauravGupta-bk2sw yeah i try

[@auughhhhhh3830]

With eyes

[@karich21]

good example for this video would be a pressure cooker.

[@benjaminion.]

Who are the 24 people that disliked this?

[@ahumanbeingmybrain9791]

28 now.. well maybe that's because they probably hate chemistry and tried to understand the concept but still didn't got it then they got angry and disliked the video.

[@nejatahmed1584]

a human being my brain 😁😂😂😂😂 interesting theory

[@iMusikkForeva]

a human being my brain 😂😂😂

[@MegaShai]

I guess they are dragging an easy topic into such complication. Dunno🤔

[@nihayaturrohmah4230]

#29

[@amal-ti2zz]

This was a really great video, but I think it bordered on inaccuracy for sake of brevity when it came to the reason water spontaneously evaporates in almost any circumstance. Yes there is a normal distribution, with outliers at any time, and a surface area with a convection current (however minute) pulling particles with them, but water sublimes from ice in Closed containers of ice cream if given enough time (freezer burn), and their distribution is NOWHERE proximal even in their most lateral limits to the boiling point of water, nor their atmospheric pressure so decreased; considered additionally in the face of waters hydrogen bonds, their seems to me something phenomenal about waters propensity to evaporate in even the most opposing conditions that either we don't understand yet, or more likely I'm unawares of up to this point- however I know many PHD chemists who say that the behavior of water remains enigmatic to us, even after all this time.