Half-life of a first-order reaction | Kinetics | AP Chemistry | Khan Academy

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  • เผยแพร่เมื่อ 23 ธ.ค. 2024

ความคิดเห็น • 33

  • @brianm.4368
    @brianm.4368 7 ปีที่แล้ว +12

    Thank you so much. This video fills a BIG gap in youtube chemistry.

  • @be4654
    @be4654 6 ปีที่แล้ว +5

    This is the only teacher on Khan that I don't really like and he is in all the videos I need :/

    • @austinham7108
      @austinham7108 6 ปีที่แล้ว +1

      He’s the AP chem teacher at my high school

  • @NanaNana-sz7xg
    @NanaNana-sz7xg 7 ปีที่แล้ว +9

    You should put number to the concentration.

  • @jeffmartineau8479
    @jeffmartineau8479 6 ปีที่แล้ว +3

    Great information! Really helpful! But please slow down a little!

  • @sararodrigues1098
    @sararodrigues1098 8 ปีที่แล้ว +3

    Thank you for these amazing lessons!!

  • @Caneladorada
    @Caneladorada 7 ปีที่แล้ว +3

    beautifully explained. thank you so much

  • @aloeverawang85
    @aloeverawang85 6 หลายเดือนก่อน

    Thank you! My textbook was so confusing and the derivation of the equation was not clearly explained anywhere! This made everything click

  • @SillyCiliate
    @SillyCiliate 11 หลายเดือนก่อน

    had to find the rate constant for an equation using that half life formula but I got a resonance cascade instead. any idea on what I did wrong?

  • @sciencenerd7639
    @sciencenerd7639 9 หลายเดือนก่อน

    thank you

  • @stunningcrafts3924
    @stunningcrafts3924 4 ปีที่แล้ว

    It is good but make your speed moderate

  • @maquensowino9588
    @maquensowino9588 6 ปีที่แล้ว

    i loved the teaching though the video is of low quality. Peace ,from Kenya.

  • @finlaymartins272
    @finlaymartins272 3 ปีที่แล้ว +1

    also -ln 0.5 = ln 2

  • @L_ofer12345
    @L_ofer12345 2 ปีที่แล้ว +1

    bro i did type in the search ''how to use the jetpack in half life'' and this what I got.

  • @shodan2002
    @shodan2002 10 หลายเดือนก่อน +1

    I was looking for half life videos i have no clue wtf any of this means

  • @WanSyazlina
    @WanSyazlina 8 ปีที่แล้ว +1

    There is this one question I don't quite understand : "Calculate half-life for first-order reaction if 68% of a substance is reacted within 66 s."
    So, how do i calculate this. And I wonder why must we use what is left of substance in the equation and not what is used up?
    ln [A] = -kt + ln [A]o
    ln 0.32 = - k (66 s) + ln 1
    k = 0.0172642 s-1
    -Why must i use 32% in the equation and not 68%?
    -And Why use ln (1) for ln [A]o in the equation?

    • @alaen2
      @alaen2 8 ปีที่แล้ว +1

      1) You're calculating the current concentration percentage of [A], 68% has reacted, so you're left with 32%
      2) 1 = 100/100 (100%), your initial concetration

    • @naweedbabakarkhail5210
      @naweedbabakarkhail5210 7 ปีที่แล้ว

      Omg I have this exact same question on one of my tests so weird.

    • @فاطمة-خ4ع8غ
      @فاطمة-خ4ع8غ 7 ปีที่แล้ว

      I have exactly the same question in one of my chemistry exercises !!!

    • @فاطمة-خ4ع8غ
      @فاطمة-خ4ع8غ 7 ปีที่แล้ว

      Naweed Babakarkhail could you contact me please! As soon as possible

    • @rainboi7894
      @rainboi7894 5 ปีที่แล้ว

      Am I the only dumb one here

  • @yashovardhanjha9274
    @yashovardhanjha9274 7 ปีที่แล้ว

    very good videos

  • @almiramuslih
    @almiramuslih 7 ปีที่แล้ว

    I. Love. This.

  • @dovestrider
    @dovestrider 3 ปีที่แล้ว +3

    i was looking for the video game half life not this

  • @edsknife
    @edsknife 4 ปีที่แล้ว

    Are you really living a life if you're not free? You're alive, but you're only living a Half-Life.

  • @rithumanoharan7098
    @rithumanoharan7098 9 ปีที่แล้ว

    Why were the initial concentrations cancelled out ?

  • @Kerwyn204
    @Kerwyn204 9 ปีที่แล้ว

    I pressed [log] then .5 and i got this answer -0.301029995 and he got -.693147... what am i doing wrong? do I need to press other buttons to get that answer?

    • @sidewaysfcs0718
      @sidewaysfcs0718 8 ปีที่แล้ว +1

      +Kerwyn204 it's a natural logarithm, log is usually interpretend as decimal logarithm (or lg) by default, find a button that says ln instead of log

    • @Kerwyn204
      @Kerwyn204 8 ปีที่แล้ว

      perfect thanks!

    • @pranjalijain3629
      @pranjalijain3629 7 ปีที่แล้ว

      K3K it is natural log of 2(and not the half) upon the rate constant (as written in all the text books) which gives the half life ..n u r right idk how he went wrong bout that concept

  • @josh4737
    @josh4737 5 ปีที่แล้ว

    he sounds like remy from ratatouille

  • @slime1167
    @slime1167 ปีที่แล้ว

    I genuinely hate school