Spectrophotometry and Beer's Law

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  • Опубліковано 29 січ 2025

КОМЕНТАРІ • 166

  • @olivxa_aa
    @olivxa_aa 5 років тому +481

    my first time seeing prof dave without long hair and my whole world has just changed

  • @TasTheWatcher
    @TasTheWatcher 5 років тому +358

    Beer's law?
    Aye, I'll drink to that.

    • @Thaumius
      @Thaumius 5 років тому +5

      *Beer Lambert Law*

    • @willm3027
      @willm3027 4 роки тому +1

      Me too

    • @rauter828
      @rauter828 3 роки тому

      @Mekhi Taylor Any method for FB hacking..

    • @masterally6025
      @masterally6025 3 роки тому +1

      Shalom Alikum
      its very obvious that its a Trap Bryant keegan and Mekhi Taylor are the same person...
      The tricks works like this: the person has an account by the name
      Mekhi Taylor and then comes and says "I don't know if anyone cares but I just hacked that and that etc etc
      Then The same person logins into another account by the name Bryant keegan and says" Oh you are right I checked it out"..
      When in reality its the same person.
      If you are seeing this.
      Whatever your real name is..
      I will use the fake names for now.. Mekhi or Bryant
      Whatever your intentions are. I hope you don't continue to trick others.
      I hope you find what you are looking for by doing something that benefits you.
      And JASMINE T P. Dont fall for such tricks. Don't click in what people asks you to Click and dont visit websites in which people tell you to visit.. Its a trap..
      Take care.
      Fi-amani-ellah

    • @rauter828
      @rauter828 3 роки тому

      @@masterally6025 I understood..I never tried..just to know what will be d reply..

  • @OFFICIALGAMELORD
    @OFFICIALGAMELORD 10 місяців тому +9

    I can't explain how to thank you .Tomorrow is my test and now I'm feeling relax.

  • @CoastalBachelor2009
    @CoastalBachelor2009 5 років тому +209

    I'm Scott Beer and I approve this message.

    • @jqyhlmnp
      @jqyhlmnp 4 роки тому +19

      Hi Scoot Beer. My name is not Scott Beer.

    • @T.J.1033
      @T.J.1033 Рік тому +1

      ​@@jqyhlmnp Hi not Scott Beer..... I'm Dark balls

    • @TRI3NERGY
      @TRI3NERGY Рік тому

      ​@@T.J.1033hi dark balls , i am niggativity

  • @dumitru-claudiusergentu6720
    @dumitru-claudiusergentu6720 10 місяців тому +10

    Hi Dave, since A is log (I/I0) and A is e*b*c, then I = I0 * 10^(-ebc), not I0*exp(-ebc) because it is not a natural logarithm but a base 10 logarithm.

  • @barbiesnack
    @barbiesnack 4 роки тому +37

    I love being able to understand something!

  • @ahmedmadhy842
    @ahmedmadhy842 4 роки тому +2

    One of the best channels in the field

  • @tommysteinbrecher
    @tommysteinbrecher 5 років тому +4

    Wow I was just lectured about this in chem and now studying for the midterm in 2 days what’re the odds hell yes professor dave

  • @rahilsiddique6950
    @rahilsiddique6950 3 роки тому +10

    Thanks a lot Professor Dave, you are literally a life saver

    • @slow_bike_show
      @slow_bike_show 3 роки тому +2

      he is he has canonically saved over 200 people from trains, mugging and chemistry mishaps. This is his penance as professor Dave caused the 2011 Fukushima Nuclear Disaster

    • @alexting827
      @alexting827 2 роки тому

      @@slow_bike_show :O??

  • @WenHanDu
    @WenHanDu 3 місяці тому +1

    In 3:36, why the log function get the relationship of e instead of 10? I really confused

  • @kylabarroga4524
    @kylabarroga4524 3 роки тому +68

    You're not professor Dave...

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +45

      Um, yes, I am Professor Dave. The channel is called Professor Dave Explains. See?

    • @gabriellanyirenda649
      @gabriellanyirenda649 10 місяців тому +20

      It's because of the short hair isn't it😂😂

    • @KaitokiNohara
      @KaitokiNohara 7 місяців тому +5

      ​@@ProfessorDaveExplainsproffessor u gonna let the imposter slide?

    • @abhisheksaha6035
      @abhisheksaha6035 6 місяців тому +2

      ​@@ProfessorDaveExplainsUmm, that made us more sceptical 🤔

  • @eewls
    @eewls 3 роки тому

    Thanks

  • @SoltanAxl
    @SoltanAxl Рік тому +1

    Thank you from Algeria 💚🇩🇿

  • @sunflora27
    @sunflora27 3 роки тому +8

    thanks professor dave! This helped reiterate what my online course just blew through rather quickly

  • @nickelpence
    @nickelpence 5 років тому +7

    Just shared the video with a friend who didn't understand wery well what they did just today at chemistry class😉

  • @Gafa996Gaddisa
    @Gafa996Gaddisa 5 років тому +8

    Hi professor.
    I always learn something from your channel.

  • @rebornmmmmuch
    @rebornmmmmuch 3 роки тому +2

    Very well explanation. Now I get the idea what this is all about🙏🏻

  • @brianbaas8650
    @brianbaas8650 5 років тому +6

    Nice first like and Comment! Loving your channel Bro, I always learn something from you 👌🏻👍🏻😁😎

  • @funnyseasonalnews8193
    @funnyseasonalnews8193 2 роки тому +2

    Thank you professor Dave I have got relevant notes

  • @samhagan1520
    @samhagan1520 5 років тому +4

    You are easily better than my chem lab ta. Thank you.
    Ps. I like the new haircut.

  • @yolo_earth
    @yolo_earth 8 місяців тому

    Thanks for your video, Professor Dave! one thing to mention, it might better to tell log used here is actually base with e, not 10. In context it explained greatly, but itself I got bit confused for secs.

  • @LittleWaffle
    @LittleWaffle 4 роки тому +3

    Thank you for this well-explained video !

  • @___S.______a.______m._______3
    @___S.______a.______m._______3 Місяць тому

    Wait at 4:40..why did we plug initial intensity as one?

  • @mongoosehunter6771
    @mongoosehunter6771 3 місяці тому

    3:34 how did that purple equation turn from the above one?

  • @ronanclark2129
    @ronanclark2129 11 місяців тому +1

    Hearing all these numbers made me anxi😢us about my homework so maybe I'll watch the rest another time

  • @joshmemarrynagdey1639
    @joshmemarrynagdey1639 Рік тому

    Thanks a lot... you make the topic easy to understand.

  • @laibakhan8380
    @laibakhan8380 Рік тому

    Proffessor Dave, I love you.

  • @rominamzf
    @rominamzf Місяць тому

    Thank you soooooo much, it is so useful for my presention

  • @woomp2004
    @woomp2004 Рік тому

    I thank you from the bottom of my heart

  • @antoniocurcino9976
    @antoniocurcino9976 5 років тому +4

    Thank you so much for the explanation!

  • @bbnnationoriginal2722
    @bbnnationoriginal2722 Рік тому +1

    Bro just causally saved my chem grade

  • @ellavaldivia6757
    @ellavaldivia6757 Рік тому

    Thank you professor David for this video.

  • @evelynvarsovia3380
    @evelynvarsovia3380 Рік тому

    Very clear explanation. thanks prof Dave

  • @organicnky7448
    @organicnky7448 4 роки тому

    My favorite on internet 💎

  • @hn-uv3vl
    @hn-uv3vl 2 роки тому

    i love you so much istg thank u 🥺 for ur content ❤️

  • @jerryhymytang8859
    @jerryhymytang8859 3 роки тому +13

    Hi professor Dave, I realized that you convert the log with a base of 10 to a exponential with a base of e, shouldn't it be in the base of 10? or else a natural log should be used instead of log in the base of 10

    • @muthegameonline
      @muthegameonline 2 роки тому +3

      I also thought the same

    • @GameHero531
      @GameHero531 2 роки тому +2

      It's unfortunate and rather annoying but some textbooks and professors use log to mean "log base e", while others use it to mean "log base 10". It makes sense to just call log base e "log" if you know where the logarithm operation originally came from, but it's confusing nonetheless

    • @CMThota
      @CMThota 2 роки тому

      ​@@GameHero531 so basically he meant log base e (ln) not log base 10?
      (the terminology is a bit new so just clarifying :))

    • @GameHero531
      @GameHero531 2 роки тому

      @@CMThota correct

    • @autonews1621
      @autonews1621 Рік тому

      thanks bro, so annoying

  • @pritykarmakar4937
    @pritykarmakar4937 2 роки тому +1

    Thank you so much sir🙏

  • @Mt.Trashmore
    @Mt.Trashmore 5 років тому +3

    Literally perfect timing!

  • @divyanshugogna6152
    @divyanshugogna6152 5 років тому +1

    thanks professor dave really helpful

  • @tuna3875
    @tuna3875 4 роки тому +7

    I just realized how Professor Dave looks like moistcritikal

  • @vicentesayson2990
    @vicentesayson2990 5 років тому +4

    Do you think sir, it's a good idea to create a spectrophotometer using specific wavelength only? For water analysis?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  5 років тому +3

      seems like an arbitrarily limitation to me

    • @vicentesayson2990
      @vicentesayson2990 5 років тому

      @@ProfessorDaveExplains can you explain further?
      By the way sir, I conducted some experiment using pasco spectrometer, i see that at 650nm wavelength the water absorbance of a distilled water is 0 , that's why i'm thinking to use 650nm as a standard source of light to determine the impurity of water

    • @Ajay-Maurya.
      @Ajay-Maurya. 2 роки тому

      @@vicentesayson2990 anything would do right? light absorved same?

  • @williamadams137
    @williamadams137 5 років тому +9

    Is “log” log base ten? Because i usually see people use “Log” or “ln” for natural log.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  5 років тому +13

      yep if the base is not specified it's implied to be 10

    • @yunus-ff2mw
      @yunus-ff2mw 3 роки тому

      @@ProfessorDaveExplains Also, in our experiments, we took the logarithmic as 10 instead of e.

  • @sithminimasha
    @sithminimasha 2 роки тому

    Thank u professor Dave💗

  • @thomone23
    @thomone23 2 роки тому

    Thx 4 U'r effort ♥️

  • @quintonwilson8565
    @quintonwilson8565 5 років тому

    Great vid, wish I saw this earlier.

  • @mermerrrrrrrrr
    @mermerrrrrrrrr 5 років тому

    Thanks for your helpful videos

  • @sammyapsel1443
    @sammyapsel1443 Рік тому +1

    Can someone point out the following:
    If Transmittance is defined as I/I0, then why isn't Absorbance defined as A=1-T , but rather as A=-log(T)?

    • @sammyapsel1443
      @sammyapsel1443 Рік тому

      What does then 1-T signify? The percentage of light that doesn't get transmitted which is not the absorbance?

  • @aniawo5119
    @aniawo5119 5 років тому

    Very useful. Thank you.

  • @defneurfaloglu855
    @defneurfaloglu855 4 роки тому

    u saved my life, thank you

  • @استبرقابراهيم-ط1ر
    @استبرقابراهيم-ط1ر 3 роки тому

    Thank you so much 💓 💗

  • @namithacd5650
    @namithacd5650 2 роки тому +17

    Can you do one for thin layer chromatography? Would be greatly helpful!

  • @TheEmperorjun
    @TheEmperorjun 3 роки тому

    Thanks a lot professor...

  • @scigrl2870
    @scigrl2870 5 років тому +11

    Hello, thank you for your videos - I show them to my undergraduate chemistry classes on occasion. However, there is an error in this video - the opposite of log is 10^x not e^x

    • @kamilewais-orozco9971
      @kamilewais-orozco9971 4 роки тому

      e^x is a notation for 10 to a power

    • @kamilewais-orozco9971
      @kamilewais-orozco9971 4 роки тому

      John Cavanaugh it doesn’t, but it’s helped me sort it out in my head

    • @krellemaster
      @krellemaster 2 роки тому

      log(x) is ambiguous and can be used to represent both base e and base 10. It is exceedingly common to use it as base e in physics.

    • @Ajay-Maurya.
      @Ajay-Maurya. 2 роки тому

      ​@@kamilewais-orozco9971 e is a special constant appearing in nature

  • @lilyanahasan8589
    @lilyanahasan8589 3 роки тому

    thank you for this!

  • @TommyZommy
    @TommyZommy 5 років тому +5

    Dave, are you considering making computer science lectures?

  • @leenalsader8476
    @leenalsader8476 3 роки тому

    Thanks 🌸

  • @gria8329
    @gria8329 2 роки тому

    On the example why is the initial intensity 1, where did that 1 came from??

  • @tnjoegaming2458
    @tnjoegaming2458 Рік тому

    Sir can u pls give a lecture about calorimeter principles and its application..

  • @AnyanwuPeterIkechukwu-nw4ri

    Please professor Dave, why do you use Iø as 1?

  • @shadali4264
    @shadali4264 2 місяці тому

    best professor

  • @jimpanse1638
    @jimpanse1638 3 роки тому

    Why is the number of moles a concentration? Isnt the concentration moles/volume? How can i get the total number of moles in the cuvet?

  • @mansurie
    @mansurie 4 роки тому

    helped a lot thanks!

  • @yarlankini2170
    @yarlankini2170 8 місяців тому

    Awesome 👍

  • @bennettegaper4344
    @bennettegaper4344 10 місяців тому

    Thank you

  • @guttipavan9306
    @guttipavan9306 4 роки тому

    easy understand. tq sir

  • @lijaucolouiserichard2320
    @lijaucolouiserichard2320 4 роки тому

    PROF. DAVE LANG MALAKAS (in filipino-only prof.dave is strong)

  • @sivasankar3349
    @sivasankar3349 Рік тому

    how 0.35 came for molar absorptivity?

  • @rosapizana8597
    @rosapizana8597 3 роки тому

    My professor used the example as an activity for the class but she asked which compound the measurement belongs to and I have no idea how to determine that.

  • @ayeshariaz8380
    @ayeshariaz8380 3 роки тому

    Is the value of incident light always taken as 1?

  • @axediepied6993
    @axediepied6993 4 роки тому

    THANK YOU!!!

  • @jagrutipaneliya4548
    @jagrutipaneliya4548 2 роки тому

    Could you give me a name of software where I can plot my graph in better way?

  • @adduct99
    @adduct99 4 роки тому

    How is the path length selected?

  • @konstantinrebrov675
    @konstantinrebrov675 5 років тому +1

    Can you teach us how to make beer from a chemist's perspective?

  • @abuhureyraat-tijani6113
    @abuhureyraat-tijani6113 3 роки тому

    2:50

  • @fabioverdi6291
    @fabioverdi6291 3 роки тому

    Help with a question ????? A compound absorb light in 227 nm. The standard curve calibration for the compound is Abs = 372x + 0,6432 which the concentration is g/100mL. The technique was analytical standard adding from fluoxetine hydrochloride (C17H18F3NO.HCl - molar mass = 345,79 g/mol). So determine the concentration in mol/L from the analysed solution. Show all calcs progression.

  • @daviskimani1890
    @daviskimani1890 Рік тому

    Hey professor can you explain on how to calculate percentage transmittance. please😊

    • @setsu2221
      @setsu2221 Рік тому

      Absorbance = 2 - log_10(%T)
      Example:
      1 = 2-log_10(T)
      T = 10%

  • @scott_meyer
    @scott_meyer 5 років тому +2

    Beer's law? Drink it.

  • @douniaelba4603
    @douniaelba4603 5 років тому

    Hi professor
    Could you do a video about asanning electron microscop plz

  • @cliffordwilliams9597
    @cliffordwilliams9597 5 років тому +6

    I'm confused how did we go from log I/i0, to e to the power of
    stuff?? Should it have been ln I/i0?????

    • @12uullaass12
      @12uullaass12 3 роки тому +2

      I think he made a mistake he mistook log(I/i0) with ln(I/i0).
      it should have been
      I = i0* 10^-(epsilon*b*c)

  • @Sirigowda2580
    @Sirigowda2580 5 років тому

    Verification of beer lambert law through colorimetric

  • @supunmalinthasandanayaka885
    @supunmalinthasandanayaka885 4 роки тому

    Good vedio ♥️

  • @twinklefavour2983
    @twinklefavour2983 11 місяців тому

    I'm August beer and i approve this video

  • @mw2nubcake
    @mw2nubcake 4 роки тому

    Fuck you're good Prof Dave

  • @mactavish1411
    @mactavish1411 4 роки тому +2

    Anyone here to learn all of AP chem for the 2020 exam? ~We're all in this together~

  • @nwerd
    @nwerd 10 місяців тому

    Clint david sala and James Hendrick Aban Shourtout🎉

  • @HaroldCornbreadCarter
    @HaroldCornbreadCarter 3 місяці тому

    I like beer, and I approve this video.

  • @ashishbhattacharya2807
    @ashishbhattacharya2807 3 роки тому

    Thanks..

  • @جهادالحربي-ق4ظ
    @جهادالحربي-ق4ظ 5 років тому

    This relate with physics or biology???

  • @KristenMedinaTenten
    @KristenMedinaTenten 4 місяці тому

    i hope this could really help me pass 😭

  • @AR-gd6yo
    @AR-gd6yo 4 роки тому

    3:18 I got lost here

    • @uguuuguunen9544
      @uguuuguunen9544 3 роки тому

      ua-cam.com/video/wxrAELeXlek/v-deo.html at around 2:35 he visualizes that and it made sense

  • @FarukUmarBello-eq1zu
    @FarukUmarBello-eq1zu Рік тому +1

    Please how did our I become 1?

    • @leenabulaban8450
      @leenabulaban8450 5 місяців тому

      did you get an answer?

    • @KituPattnaik-m2s
      @KituPattnaik-m2s 4 місяці тому +1

      It's a reference to 100%... If we call 100% as 1 then other percentage are that fraction of 1 😊.

    • @leenabulaban8450
      @leenabulaban8450 4 місяці тому

      @@KituPattnaik-m2s thank you

  • @Philosjutsu
    @Philosjutsu 5 років тому +1

    I like the look

  • @ssm-56281
    @ssm-56281 4 роки тому

    What was it about bonding? It wasn’t explained

  • @chrisyun4960
    @chrisyun4960 3 роки тому

    nice cut

  • @rassimsimou1594
    @rassimsimou1594 11 місяців тому

    Good

  • @hazemal-hajaya9049
    @hazemal-hajaya9049 3 роки тому

    👍👍👍

  • @alizedan3442
    @alizedan3442 5 років тому

    Greaaaaat

  • @curtpiazza1688
    @curtpiazza1688 3 роки тому

    👍

  • @petranuth7112
    @petranuth7112 4 роки тому

    Beer Lambert's Law

  • @yayapuncio497
    @yayapuncio497 2 роки тому

    the more of a substance the light travels through

    • @yayapuncio497
      @yayapuncio497 2 роки тому

      the more of it that will be absorbed

    • @yayapuncio497
      @yayapuncio497 2 роки тому

      the higher the concentration the more of the substance will be absorbed