Hess's law and reaction enthalpy change | Chemistry | Khan Academy

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  • เผยแพร่เมื่อ 29 ม.ค. 2025

ความคิดเห็น • 259

  • @Karamel159
    @Karamel159 8 ปีที่แล้ว +48

    This video series saved my chemistry grade this unit. A two-hour lecture and meeting with the teacher after school didn't stick, but somehow this made everything click. Thank you!

  • @bilalbhatti9898
    @bilalbhatti9898 12 ปีที่แล้ว +17

    This guy is awesome. Only 30 minutes ago, he was helping me with multiplying matricies, and now he is helping me with chemistry. I love it. :)

  • @massimo.pericolo.w
    @massimo.pericolo.w 14 ปีที่แล้ว +50

    You just made my whole semester of chemistry obsolete. I thank you for that.

    • @bluehourcore
      @bluehourcore 4 ปีที่แล้ว +8

      wow this comment is 9 yrs old thats insane im studying it now

    • @inox3nt545
      @inox3nt545 4 ปีที่แล้ว +1

      @@bluehourcore lol same😂🙌🏻

    • @bluehourcore
      @bluehourcore 4 ปีที่แล้ว +2

      @@inox3nt545 nice 🙌🏻😂

    • @hodralamesa5672
      @hodralamesa5672 2 ปีที่แล้ว +1

      I’m studying now 2023 😢

  • @kentheg7368
    @kentheg7368 9 ปีที่แล้ว +28

    OMG. If i had found this like 2 hours ago, so much time would have been saved. Thanks so much, this was very helpful.

    • @EmmyKhan
      @EmmyKhan 8 ปีที่แล้ว

      Ken The G or like 2 months ago haha

    • @Zen_Zen_Zense
      @Zen_Zen_Zense 5 ปีที่แล้ว

      @@EmmyKhan more like 3years

    • @Pasta_fries
      @Pasta_fries 4 ปีที่แล้ว

      @@Zen_Zen_Zense
      lol

  • @SapphireEmeralds
    @SapphireEmeralds 14 ปีที่แล้ว +1

    One of my chemistry teachers spent 2 weeks trying to explain that to me, and pretty much failed-- and this video simplified it WAY more than he did.It makes sense now! Thankyou.

  • @DanceIsPassion411
    @DanceIsPassion411 13 ปีที่แล้ว +3

    Oh my goodness, it feels as though the world all makes sense! Thank you so much for helping me out with Chemistry! If I ever get stuck again, I will definitely come back to watch more of your videos.

  • @anonymouspersimon
    @anonymouspersimon 3 ปีที่แล้ว +1

    How I wish all teachers talk in moderate speed and a lot of patience like you Mr.Khan

  • @surfer3595
    @surfer3595 13 ปีที่แล้ว

    Mr. Khan,
    Saying you videos are helpful would be an understatement. The only thing I would like to see more, which you do in some videos, is a brief overview of the general steps/equations used. I find this extremely helpful especially in the longer videos that have a lot of content. Keep it up!!!!

  • @s17srw
    @s17srw 4 ปีที่แล้ว +1

    Slight arithmatic error, 6x-1714.98=_1714.98, the video was still very useful for my exam, thanks :)

  • @22putu2
    @22putu2 13 ปีที่แล้ว +1

    Chemistry exams in 22 hours and i couldn't figure shit out of this until i came across your video, what a relief....thank you Mr Khan :)

  • @Ariccio123
    @Ariccio123 13 ปีที่แล้ว +1

    My Chemistry final is tomorrow.
    I have learned more in watching Khan academy for the past 2 hours than I have learned in an entire year of class.
    --Speechless--

  • @GraceKi92
    @GraceKi92 14 ปีที่แล้ว +1

    Where have you been all my life
    GREAT explanation.. i understood first time round.

  • @rjyork25
    @rjyork25 12 ปีที่แล้ว

    no matter what i am trying to understand i come to khanacademy and everything is understood so clearly, i wish you were my professor!!!!

  • @andrewleonard7540
    @andrewleonard7540 6 ปีที่แล้ว +92

    Welp, I might fail my chem test.

    • @kennethdale6877
      @kennethdale6877 3 ปีที่แล้ว +2

      Any update? (even thought it’s too late to ask😂😭)

    • @user-mq1hq6ox1e
      @user-mq1hq6ox1e 3 ปีที่แล้ว

      @@kennethdale6877
      Ikr 😂😂

    • @Yaqqq178w93
      @Yaqqq178w93 3 ปีที่แล้ว

      Let the people know

    • @andrewleonard7540
      @andrewleonard7540 3 ปีที่แล้ว +3

      @@kennethdale6877 Sadly I do not remember.

  • @Porkchopzngravy
    @Porkchopzngravy 11 ปีที่แล้ว

    God bless you, seriously. I had this concept explained to me by so many people but I did not get it until I actually stumbled upon this video.
    I wish I had known about this channel at the beginning of the semester.

  • @nhargravealton
    @nhargravealton 13 ปีที่แล้ว

    You my friend, are a life saver. I have A Level Chemistry coursework tomorrow afternoon and all I know is it's on enthalpy changes....which I knew hardly ANYTHING about before this. I couldn't sleep last night because I was worried I wasn't going to understand it. This video has helped so much. Thanks enternally :)

  • @Hellgoregaming
    @Hellgoregaming 13 ปีที่แล้ว

    The best part of his videos is the fact that they're videos, pause, replay etc, etc.

  • @yuhsin2006
    @yuhsin2006 12 ปีที่แล้ว +1

    thank you soooooooo much, i've been sit in my chem class since school starts and now i understand everything just by this 15 min video..

  • @stev019
    @stev019 14 ปีที่แล้ว +1

    Your video confirms that I know what I'm doing. Thank you =)

  • @susanh2523
    @susanh2523 6 ปีที่แล้ว +5

    this video remains great after 9 years! #teamkhanacademy

  • @TheKhulKid
    @TheKhulKid 12 ปีที่แล้ว +7

    You prove why all teachers should be fired and why we should simply learn from amazing teachers at home like you.

  • @highoctaneman2
    @highoctaneman2 14 ปีที่แล้ว

    Test tomorrow! You made all of my studying make sense. It's all clear now. :)

  • @AM-qz9kw
    @AM-qz9kw 8 ปีที่แล้ว

    no one else can explain it properlt, thank you for simplifying and not using unnecessary arrows all over tha place

  • @JustinPlaxton
    @JustinPlaxton 13 ปีที่แล้ว

    this was REALLY helpful i have been studying this for two hours and didn't get it then in 15min i completely understand thank you!

  • @321carmen
    @321carmen 11 ปีที่แล้ว +2

    your voice is strangely soothing

  • @wc7vdaner
    @wc7vdaner 13 ปีที่แล้ว

    U make me regain my confidence in understanding this.... tear*

  • @ibbyizaG
    @ibbyizaG 12 ปีที่แล้ว

    its so fun and easy watching you videos that it doesnt even feel like im studying, even though im learning stuff like crazy xD

  • @fleshcookie
    @fleshcookie 12 ปีที่แล้ว

    8:58- 9:10 = hilarious calculator indecision. Sal you crack me up.

  • @zramdeen
    @zramdeen 15 ปีที่แล้ว

    u da BOSS ... i was absent the day my teacher taught this.. ty for explaning

  • @ISTARI22
    @ISTARI22 14 ปีที่แล้ว

    OMG! Dude u rock man. I didnt understand a thing during my lecture earlier. After watching i understand now. Thanks to you. You should be a professor:)

  • @SuperJbob1234
    @SuperJbob1234 8 ปีที่แล้ว

    just got an A- on my AP Chem final. Couldn't have done it without you

  • @chaserzx383
    @chaserzx383 8 ปีที่แล้ว +1

    thanks really helpful. as the other person mentioned, if only I had found it 2 hours ago.

  • @spiderdude423
    @spiderdude423 15 ปีที่แล้ว

    if it was not for you this semester i would be failing college chemistry, keep up the good work sir

  • @Jesus_is_Good_God
    @Jesus_is_Good_God 5 ปีที่แล้ว

    I missed a lecture on this topic and understanding it mainly on the textbook was kind of complex, but after watching this simplified powerful video with examples, I am now adept at this topic!!!😍 thanks so much

  • @sosburn24
    @sosburn24 13 ปีที่แล้ว

    You may have just saved my life! Thank you!
    I haven't been sure how to even begin studying but this has helped

  • @ditchdigger126
    @ditchdigger126 14 ปีที่แล้ว +2

    great explanation!! I should start skipping my chem class and watching youtube teaching videos instead, I would probably learn more. Thanks for the video!

  • @TadanoCandy
    @TadanoCandy 11 ปีที่แล้ว

    I understood almost nothing till I watched this video. I wont fail my test tomorrow!
    Very Grateful!!! :D

  • @Bigaldaomeister
    @Bigaldaomeister 12 ปีที่แล้ว

    KhanAcademy, thank you very much for these tutorials. They've saved my arses many times over.

  • @LiveLoveLaff20
    @LiveLoveLaff20 14 ปีที่แล้ว

    you are my second ap chem teacher!

  • @commandobilly113
    @commandobilly113 9 ปีที่แล้ว +2

    Holy shit, now it's clear to me. Thank you!

  • @xmasta105
    @xmasta105 12 ปีที่แล้ว

    great video i learned more in 16 min than i did in a week

  • @jamiethaigirl123
    @jamiethaigirl123 13 ปีที่แล้ว

    Thank you so much, Dr. Khan! You explained it a lot better than my teacher.

  • @alexmotaf
    @alexmotaf 14 ปีที่แล้ว

    Amazing lesson!! I was strugling with that all night until i saw your video! thank very much!

  • @mafiaSage105
    @mafiaSage105 13 ปีที่แล้ว

    this video makes my life easier, thank you mr. khan

  • @shatzE3
    @shatzE3 13 ปีที่แล้ว +1

    THANK YOU SO MUCH!! u finally cleared my confusion. I go to the (currently) 4th best skl in the UK nd my chem teacher is still could get this through my head but u done it 15mins lool

  • @snnacho
    @snnacho 14 ปีที่แล้ว

    I did find that helpful. Thanks Sal.

  • @rahrahritaa
    @rahrahritaa 13 ปีที่แล้ว

    back to this video.
    i bombed this last test because my professor drops the lowest grade and i already did well on the other ones, but the final is next week!!! need to understand this video.

  • @sosburn24
    @sosburn24 13 ปีที่แล้ว

    You may have just saved my life! Thank you!

  • @aditya7784
    @aditya7784 11 ปีที่แล้ว +1

    thanks it helps me understand more. Can you talk about different types of enthalpies such as atomisation, bond, enthalpy of solution, lattice enthalpy.

  • @DOSKOIxPITA
    @DOSKOIxPITA 14 ปีที่แล้ว +1

    great! thank you for the valuable knowledge!!!

  • @kenonumaku23
    @kenonumaku23 6 ปีที่แล้ว +1

    "Hope you found that helpful"...are you kidding me, just helpful? you are a hero indeed!

  • @carlkazuma
    @carlkazuma 15 ปีที่แล้ว +1

    Thanks!, Very helpful!

  • @shauryaverma2705
    @shauryaverma2705 2 ปีที่แล้ว +1

    You are a legend sir ❤️

  • @Jonwh18
    @Jonwh18 12 ปีที่แล้ว

    I don't know why I even bother going to class I learn more watching these.

  • @snnacho
    @snnacho 14 ปีที่แล้ว

    @Pablothe you should probably make a video showing everyone how to do Thermochemistry now...

  • @brennaransom6015
    @brennaransom6015 11 ปีที่แล้ว

    YOU ARE A GOD!!!!!! THANK YOU SOOOOOO MUCH!!!! YOU ARE GOING TO SAVE MY HONORS CHEMISTRY GRADE :-)

  • @SeekTheTruthAndTruth
    @SeekTheTruthAndTruth 7 ปีที่แล้ว

    full clarity .explained very well.thanks

  • @annan1593
    @annan1593 9 ปีที่แล้ว +3

    Wow this video was great! Thanks so much

  • @dcolyer
    @dcolyer 12 ปีที่แล้ว

    Thank you for all of your help. When I'm rich I will donate many treasures to you.

  • @MJ5347
    @MJ5347 12 ปีที่แล้ว

    This was so helpful, THANK YOU SO MUCH! you have saved me from hours of confusion.

  • @allenspacer5345
    @allenspacer5345 10 ปีที่แล้ว +16

    YOUR ARE MY HERO!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

    • @IsabellKay9965
      @IsabellKay9965 9 ปีที่แล้ว +6

      You're*

    • @allenspacer5345
      @allenspacer5345 9 ปีที่แล้ว +1

      +Isabell Kay Easy English teach, mistakes do happen( and yes, i meant to say teach not teacher).

    • @abdullahbukhari1469
      @abdullahbukhari1469 6 ปีที่แล้ว +2

      Kay Dude you gotta watch your attitude. It doesn't take god a lot of time to humiliate man. Think your English rocks. Help somebody then.

  • @bethan9597
    @bethan9597 8 ปีที่แล้ว +3

    Saved my chemistry as level! Thanks:)

    • @zeinamazin3743
      @zeinamazin3743 7 ปีที่แล้ว

      lol same :-)

    • @sonuthapa6090
      @sonuthapa6090 6 ปีที่แล้ว

      Zeina Mazin will be giving on oct/nov session! I literally have no idea on how to draw enthalpy cycle.

  • @UnderCoverPope
    @UnderCoverPope 12 ปีที่แล้ว

    i had to stand up and clap for 5 minutes after this video out of amazement

  • @DavidImanuelWidjaja
    @DavidImanuelWidjaja 12 ปีที่แล้ว

    studied 2 week @school. 15 min with khan academy

  • @nawalasif786
    @nawalasif786 13 ปีที่แล้ว

    thanks man great explanation! looks like i dont have to fail chem this year! :)

  • @SPRIIKO
    @SPRIIKO 14 ปีที่แล้ว

    You sir, are better than my disgusting Chemistry teachers. Kudos to you.

  • @ehsunmalikmalik5043
    @ehsunmalikmalik5043 7 ปีที่แล้ว

    7 years laters this video still a saver

  • @TheNumber2Pencil546
    @TheNumber2Pencil546 13 ปีที่แล้ว

    your voice is interesting...but at the same time soothing haha

  • @albanianmusiclove1934
    @albanianmusiclove1934 10 ปีที่แล้ว +2

    YEEESSS!!! Now it makes sense! Thank You :) :)

  • @susielharris
    @susielharris 14 ปีที่แล้ว

    Omg thank you so much. This actually made sense to me.

  • @throughkaleidoscopes
    @throughkaleidoscopes 12 ปีที่แล้ว

    that was so helpful! thank you so much khanacademy! :D

  • @donothack
    @donothack 11 ปีที่แล้ว

    This video helped me a ton, thanks

  • @kayathon
    @kayathon 14 ปีที่แล้ว

    now i totally get it, thankyou so much :)

  • @Annie209511
    @Annie209511 13 ปีที่แล้ว

    thank you! I might actually pass Chemistry now! My lecturer sucks :/

  • @SuperTajman
    @SuperTajman 14 ปีที่แล้ว

    For the combustion of propane you would get water vapor, your state on the water should be gas.

  • @Ibahz
    @Ibahz 13 ปีที่แล้ว

    thank you dr. khan. you make learning fun

  • @matthewheide6816
    @matthewheide6816 12 ปีที่แล้ว

    you are #1 in my book

  • @chuckharrell6409
    @chuckharrell6409 8 ปีที่แล้ว

    God bless your soul Sal

  • @iambarbie1234
    @iambarbie1234 13 ปีที่แล้ว

    you are amazing!
    thank you so much

  • @k-zo2805
    @k-zo2805 6 ปีที่แล้ว

    Thanks man. You’re gifted

  • @SmileyAnnii
    @SmileyAnnii 11 ปีที่แล้ว

    My god, your videos always save me!!! Thank you so much

  • @youssefm.al-aasar8788
    @youssefm.al-aasar8788 8 ปีที่แล้ว +20

    the propane is in a gaseous state, not liquidous.

  • @jaiparkash9164
    @jaiparkash9164 5 ปีที่แล้ว

    thanks it helped me a lot

  • @owatonna06
    @owatonna06 13 ปีที่แล้ว

    thank you again u the best.....

  • @kutecurse6060
    @kutecurse6060 13 ปีที่แล้ว

    I want to meet u :( u are sucha genius! :o

  • @shopanab1547
    @shopanab1547 9 ปีที่แล้ว

    Thanks so much for this🙏🏽

  • @abbask908
    @abbask908 10 ปีที่แล้ว

    Awesome, saved my ass for honors chem tomorrow

  • @ThebirdmanTrainer
    @ThebirdmanTrainer 13 ปีที่แล้ว

    This made this so much easier, Holy shit!

  • @Sasha7amad
    @Sasha7amad 15 ปีที่แล้ว

    Loved this!!!

  • @choogiesaur
    @choogiesaur 11 ปีที่แล้ว

    amen brotha. in your situation right now

  • @RockNLoad07
    @RockNLoad07 13 ปีที่แล้ว

    @shatzE3 Rewatch it and listen to him carefully, Water is - 285.53, his - and 2 just combined so it looks like plus.
    Easy mistake to make though if you didn't hear him or watch him pick it off the list.

  • @lishwark5345
    @lishwark5345 7 ปีที่แล้ว

    u r the best in the world

  • @thingyjim
    @thingyjim 11 ปีที่แล้ว

    My brain adores you.

  • @ZuhayrSIslam
    @ZuhayrSIslam 5 ปีที่แล้ว

    Thank you very much

  • @bnz7253
    @bnz7253 6 ปีที่แล้ว

    Thank you, very helpful

  • @victoriajarosh1713
    @victoriajarosh1713 9 ปีที่แล้ว +2

    Fantastic

  • @BethanyA
    @BethanyA 13 ปีที่แล้ว

    THANK YOU GOOD SIR

  • @tayseerbruh8229
    @tayseerbruh8229 4 ปีที่แล้ว

    holy crap this video is 11 years old, anyway this really helped me

  • @IcySilverScenic
    @IcySilverScenic 12 ปีที่แล้ว

    Khanacademy you make the teachers looks bad... In a good way! :D

  • @josh170797
    @josh170797 10 ปีที่แล้ว

    Thank you so much !!!