The Mole: Avogadro's Number and Stoichiometry

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  • čas přidán 5. 07. 2015
  • Yes, I know moles are adorable furry creatures. This is a different kind of mole! A numerical mole. And we need to understand them to be able to make predictions about reactions. Let Professor Dave take you through the finer points.
    Watch the whole General Chemistry playlist: bit.ly/ProfDaveGenChem
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Komentáře • 473

  • @indrareddyakkaluri3733
    @indrareddyakkaluri3733 Před 6 lety +231

    Your intro is legendary

  • @lordwetrustl7080
    @lordwetrustl7080 Před 6 lety +1245

    I knew Jesus was a teacher but i didn't know he taught chemistry

    • @hehehehaw7
      @hehehehaw7 Před 5 lety +59

      Underrated comment, take my upvote.

    • @fallencity4066
      @fallencity4066 Před 4 lety +25

      Sophisticated comment about underrated comment , Here take my up-vote.

    • @elmerlopez4146
      @elmerlopez4146 Před 4 lety +14

      Piggintins my chem teach calls him science Jesus

    • @grantlong7788
      @grantlong7788 Před 4 lety +11

      he is NOT jesu:(

    • @marktaylor7162
      @marktaylor7162 Před 4 lety +13

      I thought Jesus was a car mechanic, because Jesus built my hotrod.

  • @matthewcecil8552
    @matthewcecil8552 Před 7 lety +100

    I'm a senior biomedical science student from FSCJ, and previously a tutor. You did a great job in this video. Definitely a clear and concise explanation, which is the most important aspect of any chemistry lesson with maths.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Před 7 lety +19

      thanks kindly!

    • @missishu2431
      @missishu2431 Před 7 lety +3

      Sir you really maid my day...i finally got interested in Chemistry

    • @tonybatycki
      @tonybatycki Před 2 lety +3

      Wow never expected to see FSCJ in a comment. Anyway, Go Jags!

    • @josiahwhite3157
      @josiahwhite3157 Před 5 měsíci +1

      @@missishu2431Ain’t no way u said “maid” learn grammar wit yo goofy ahh

    • @MoleLife-mn9bq
      @MoleLife-mn9bq Před měsícem

      I am the real Mole

  • @mitchyboy41
    @mitchyboy41 Před 3 lety +302

    Just wanted to say, to all the students, trying to comprehend this, you're not alone. I've pulled out my hair for 3 days trying to learn this.
    Just breathe, getting frustrated won't allow you to learn it any easier.

    • @AAIVE
      @AAIVE Před 3 lety +5

      thanks, mitch!

    • @misfire32
      @misfire32 Před 3 lety +1

      @@simoncharlene8947 Thx

    • @megajihamsikaa
      @megajihamsikaa Před 3 lety +1

      Thank you

    • @real_GANGSTA_
      @real_GANGSTA_ Před 2 lety

      Which standard you are in

    • @SCP--mw7tx
      @SCP--mw7tx Před 2 lety +1

      i struggled for a few days, and then soon realized it's just some easy mathematics.

  • @zucchini9177
    @zucchini9177 Před 6 lety +113

    OH MY GOSH I AM ABOUT TO CRY! I have a test on this tomorrow and know nothing about the material but now that I've watched this I finally do. Thank you so much!!!!!

  • @Fjuron
    @Fjuron Před 2 lety +24

    To fully understand, I often have to watch your videos twice or pause because the information is so densely packed.
    But I love it. Feels very good when you figure it out. It forces you to think about it in your own way and build your own mnemonic. Active learning. 👍

  • @charlieann8661
    @charlieann8661 Před 7 lety +13

    Thank you for taking the time to do these videos!

  • @freedomofspeech122
    @freedomofspeech122 Před 8 lety +84

    Thank you for all of your videos! You're a great teacher. Thanks for all of your hard work and efforts to help us chem students!

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Před 8 lety +22

      +May C it's my great pleasure! spread the word!

    • @freedomofspeech122
      @freedomofspeech122 Před 8 lety +7

      +Professor Dave Explains I sure did! I shared your channel with a few homeschooling Facebook groups in BC, Canada.

    • @tonybatycki
      @tonybatycki Před 2 lety +2

      @@ProfessorDaveExplains any recommendations of books about Avogadro and the process of how he developed his equation? Fascinating that he found this number.

  • @expiredflunky5603
    @expiredflunky5603 Před 6 lety +108

    Thank you jesus

  • @christinayang2658
    @christinayang2658 Před 2 lety +6

    okay you know what I got an A in chemistry in highschool but never knew the purposes of these concepts..... I really enjoy your constant reasoning on why we use moles in the first place! It really puts the whole picture into perspective vs just having my teacher mostly explain the math portion so I just learned how to do the math to get correct answers on my exam and homework..... the big picture and purpose for me was for sure lost. Thank you for your reasonable explanations!

  • @xdanx01
    @xdanx01 Před 7 lety +56

    I finally get stoichiometry! Thank you so much for this video

  • @doremi1414
    @doremi1414 Před 2 lety +13

    I'm a Korean student and I'm really into science. Your videos helps me a lot cause you use simple words, giving great explains. You are the best prof for me. Thanks a lot for your hard work.

    • @kentheengineer592
      @kentheengineer592 Před rokem

      Learn More About Analytical Math & How to Think in Abstraction

    • @doremi1414
      @doremi1414 Před rokem

      @@kentheengineer592 Maybe in university. thanks for the recommendation

    • @williamconrad1087
      @williamconrad1087 Před 4 měsíci +1

      By simple, you mean words like stoichiometry and stoichiometric.

    • @TenNineD
      @TenNineD Před měsícem +3

      @@williamconrad1087it’s like Dave saying “for example” rather than saying “For a concrete demonstration of the illustration, we can observe”

  • @titidechdamrongwut1351
    @titidechdamrongwut1351 Před 7 lety +5

    Keep pushing this VDO , I will go thru all your VDO. Thank you 3 times.

  • @---fb6zs
    @---fb6zs Před 6 lety +8

    Very easily to understand! Thank you so much 😊 I will watching all of your videos ❤️

  • @kent7966
    @kent7966 Před 5 lety +29

    I have been using his videos to study for midterms

  • @sarayhazuki4709
    @sarayhazuki4709 Před 4 lety +2

    Thank you so much for your videos! your videos are short and have all the information, plus your illustrations help a lot to understand more!

  • @austinsporn8432
    @austinsporn8432 Před 7 lety +56

    you have saved me

    • @wilts8965
      @wilts8965 Před 4 lety +6

      I see what you did there

  • @edwintafalla589
    @edwintafalla589 Před 3 lety +1

    Thank you Professor Dave. So much learning about your upload videos

  • @OIOTV-zo9qp
    @OIOTV-zo9qp Před 7 lety +9

    Thank you for helping. hard to find people like you. I am going to share it. Thanks

  • @stu_0618
    @stu_0618 Před 3 lety +1

    You litterally saved my chemistry GCSE. Thank you so much!

  • @saitejamandiga2916
    @saitejamandiga2916 Před 6 lety +3

    Thanks for all of ur videos sir
    My sir taught us but I didn't understand but after seeing ur videos anyone won't have ang doubts

  • @ajibolakehindeaishat5892

    Thanks for all your chemistry videos

  • @veryhealthy9962
    @veryhealthy9962 Před rokem +7

    If you are a self-learner, believe me when I say the amount of info Dave puts per video is extremely dense, but listen patiently and let it run through your brain until you get it. That tingle in the brain is similar when you finally understand something in arithmetics!

  • @jackmorvan813
    @jackmorvan813 Před 4 lety

    Great video, David!

  • @gbmsg282
    @gbmsg282 Před 3 lety

    First time I was able to actually understand the reason behind all those calculations. Thanks man!

  • @GriteKidsTV
    @GriteKidsTV Před 3 lety +10

    i wasnt listening in class last time and i have a test, you just saved my ass

  • @akira_asahi
    @akira_asahi Před 2 lety

    Thank you for the video. I am grateful for your time and contribution. Kind regards, Akira.

  • @inoxide5454
    @inoxide5454 Před 9 měsíci +8

    i love being taught by a Foo Fighter

  • @mychaelpierce8049
    @mychaelpierce8049 Před 2 lety

    Great video. Thanks for sharing!

  • @angeliemaebonaobra4448
    @angeliemaebonaobra4448 Před 7 lety +1

    Professor Dave! Thank you!

  • @zeinabmuhammed4549
    @zeinabmuhammed4549 Před 6 lety +3

    Thank you professor dave 😇

  • @jzzh1
    @jzzh1 Před 6 lety +5

    thanks so much! you got a new subscriber

  • @user-ww3pf4cr8c
    @user-ww3pf4cr8c Před 3 lety

    Your explains is more than great Mr Dave👏👍

  • @jacquelineoonzhien3234

    Thank you so much for the video!

  • @maesie_alexa4084
    @maesie_alexa4084 Před 3 lety

    Watching 2 hours before deadline!! Thank youuu

  • @alexandrashields2600
    @alexandrashields2600 Před 3 lety

    Dude, thank you so much for helping explain this!! Bravo!!

  • @praviinashanbalagan1563
    @praviinashanbalagan1563 Před 7 lety +6

    You have everything I need thanks how about making video clips of you doing experiment in General chemistry maybe it helps me to know the procedure

  • @stupidsapien7304
    @stupidsapien7304 Před 2 lety

    Thank you professor ! It helped me alot.

  • @sunflowervol.6790
    @sunflowervol.6790 Před 6 lety +32

    Thank you so much sir. It's probably the best way to explain it so simply😊...A small request sir, Can we have an extended video on the same topic as it is a whole big chapter piled up.... plz do it if possible sir.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Před 6 lety +26

      what's not in this one that you're looking for? it might be in another clip.

  • @connerbrandy9185
    @connerbrandy9185 Před 3 lety

    Thank you, Helped a lot!!

  • @callumalmighty
    @callumalmighty Před 2 lety

    Nice one Dave!

  • @socceralex12345
    @socceralex12345 Před 7 lety +8

    Thx 4 the vid

  • @MARTZX1111
    @MARTZX1111 Před 3 lety +1

    Thank u for this tutorial.. its very helpful..

  • @dominicnikon6276
    @dominicnikon6276 Před 5 lety +1

    Awesome video thank you so much

  • @triple_gem_shining
    @triple_gem_shining Před 9 měsíci

    literally love dave

  • @jimjimmy3131
    @jimjimmy3131 Před 6 měsíci +2

    I got only one question, why did that chemistry teacher that hated her job and students in general made my day so difficult instead of simply explaining to a 15 year old kid such a formula. Hod damn, why do teachers become teachers when they cannot teach and dislike kids ffs.😅 even after all those years of this video being uploaded. I would like to thank you for the explanation.

  • @steezyspamsl223
    @steezyspamsl223 Před 5 lety +11

    saving me from chemistry finals 😂😭

  • @peterclancy3653
    @peterclancy3653 Před 10 měsíci

    All I can remember of stoichiometry is warm summer days, blowflies buzzing on the windows and the drone of a old chem teacher. 56 years ago. AD(after Dave ) it finally clicked!

  • @just7815
    @just7815 Před 2 lety +1

    prof dave is a genius. he makes a lesson no brainer.

    • @Dragon-Slay3r
      @Dragon-Slay3r Před 9 měsíci

      That was the najd interview yesterday

  • @jimbynumsierravistahs2319
    @jimbynumsierravistahs2319 Před 4 měsíci +1

    I want to use this in a high school chemistry class. My issue is the ambiguity when it comes to where the numbers came from when going from mole of 1 thing to moles of the other. Somehow emphasizing that the numbers came from the balanced equation would prevent a lot of confusion.

  • @sskybluezen
    @sskybluezen Před 4 lety +1

    I suck at chemistry, but after watching couple of your vids I might pass in my upcoming exam. Thanks a lot !!!!!

  • @ammyvl1
    @ammyvl1 Před 2 lety

    it took me a couple tries but I got it! thanks so much

  • @priovag2632
    @priovag2632 Před 3 měsíci

    Your teaching is great

  • @linaberkani309
    @linaberkani309 Před 4 lety

    Thank you sooooo muuuuch

  • @slimeymeatballs
    @slimeymeatballs Před 2 lety +2

    My chem teacher made me watch this. I still don’t understand shit

    • @s2sboc38
      @s2sboc38 Před 2 lety

      Yo this tweet doin numbers

  • @k_Why
    @k_Why Před 2 lety +1

    Just had a quick question.
    I did the comprehension exercise in kind of a roundabout way calculating the weight of the CO2 and H2O then using both those values to figure out the weight of the O2 and adding them.
    I got the right result, but the weight on both sides of the equation isnt actually the same. I got 92,7g on the left side and 95,4g on the right side.
    I doubt that we actually created mass anywhere especially because this looks like a combustion reaction that releases energy. Mass defect wouldnt be enough to explain almost 3 grams anyway.
    Now did i just miscalculate and got the right solution through dumb luck or what's going on?
    Edit: figured it out. i mistakenly used 46 as the as the atomic mass for CO2 when its actually 44. i still got the right solution because i devided by that same number when i converted to O2

  • @madylinn9235
    @madylinn9235 Před 5 lety +1

    Thanks prof

  • @Dragon-Slay3r
    @Dragon-Slay3r Před 9 měsíci +1

    Ive already been stung there 😂

  • @HenriFaust
    @HenriFaust Před 2 lety +4

    In the first example, you rounded once for each conversion factor. In the second example, you combined all the conversion factors into a single operation and only rounded at the end. These are not the same method, and achieve differing results.
    *Method 1:* 32.8 g H2O and 73.0 g O2
    *Method 2:* 32.7 g H2O and 72.7 g O2
    Which method of rounding is correct?

  • @old-tech
    @old-tech Před rokem +1

    Remember that, like he said, the answer may very depending on where you round. In the case of the comprehension question, the answer is based on if you didn't round until the last number, which totaled to 72.7. If you did what he did in the first example question, and round the answer of 20 • (1/44) to 0.455, you'd end up with 72.8g for the final answer. If you ended up with that, you technically didn't do it wrong. Again, as Professor Dave said, it depends on when you round.

    • @DaveGrean
      @DaveGrean Před rokem +1

      Thanks for reminding me, I got 72,8 despite having used a calculator so I was losing my mind, lmao

  • @adhiyanthaprabhujeyashanka2091

    Yes I finally understood this😉, thank you so much professional professor dave, love from India 😁, I will suggest to my friends to watch you, the best as always ❤️

  • @loshithasahan7164
    @loshithasahan7164 Před 6 lety +3

    Before I watch this video this lesson made a MASSIVE headache for me.......THANK YOU VERY MUCH PROFESSOR DAVE !

  • @incrediblestudios5609
    @incrediblestudios5609 Před 2 měsíci

    I love you Professor Dave

  • @ciaranlonergan9910
    @ciaranlonergan9910 Před 3 lety

    Love you Dave

  • @Roy-mk9zl
    @Roy-mk9zl Před 5 lety +1

    Thanks sir.

  • @user-xu6ie9js9z
    @user-xu6ie9js9z Před 2 měsíci

    Bro is about to measure the amount of alcohol molecules that he's going to turn his glass of water into.

  • @arway4766
    @arway4766 Před 3 lety +2

    I don't know how good you are at making music but could you possibly make a full "professor dave explains" song... Idk what lyrics you'd put into it but you're the expert add some science topics make them rhyme do whatever it honestly doesn't matter as long as I get a longer version of the intro lol

  • @fallennarcotic6981
    @fallennarcotic6981 Před 2 měsíci +1

    I get the math. I get the reason. What I don’t get is how can we assume that every molecule has exactly a mole of atoms?

  • @ameennasser5674
    @ameennasser5674 Před 8 lety +34

    i didn't like chemistry till saw your chanel
    thank you boss

  • @MsAsh496
    @MsAsh496 Před 6 lety +2

    You are a gift from God, ... would you mind doing more o-chem videos?!

  • @ansumann
    @ansumann Před 2 lety

    Thank you so much

  • @Dg-ii5xk
    @Dg-ii5xk Před 2 lety

    Thanks a lot!

  • @newone8463
    @newone8463 Před 6 lety +2

    Thank you 'awesome' broh

  • @irenecuartocruz6371
    @irenecuartocruz6371 Před 4 lety +1

    Thank you because we have a reporting about this... Thank you very much... It is a big help...

  • @study4life443
    @study4life443 Před rokem +3

    Hello, I've been confused at 4:03 Where did 1moleC3H8/44.0 g C3H8 come from? I know that we need to multiply by one in order to not change the equation, the thing that's confused me is how do we know that C3H8 has a mass of 44.0 g.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Před rokem +5

      It's the molar mass, just use the periodic table.

    • @spitfire184
      @spitfire184 Před 5 měsíci

      For anyone reading this after the fact, I think it's:
      Carbon (6 protons + 6 neutrons) x 3 = 36
      Hydrogen (1 proton + 0 neutrons) x 8 = 8
      36 + 8 = 44

  • @AmarSingh-xf8di
    @AmarSingh-xf8di Před 7 lety

    good video of chemestry

  • @cardiyansane1414
    @cardiyansane1414 Před 2 lety +2

    @ 5:24 It looks like they have done two conversions at the same time , maybe it would be easier to understand it is broken down step by step

  • @bilimAdimlari
    @bilimAdimlari Před 2 lety

    you're good teacher

  • @oluwatosinoluwafemi6331

    You are so wonderful !

  • @jobekirkuk
    @jobekirkuk Před 2 lety +1

    Your videos are Nuklary. Good job

  • @atanaciogarza7176
    @atanaciogarza7176 Před 3 lety

    Thank you

  • @Decco6306
    @Decco6306 Před 3 lety +1

    This guy is like an alternate universe MoistCr1TiKaL where he studied to become a scientist and a professor.

  • @universal6906
    @universal6906 Před 3 lety

    Thanks for
    You clear my dought

  • @narniansworld9735
    @narniansworld9735 Před 3 lety

    Thank you sir ❤️🙏🙏

  • @sunflowervol.6790
    @sunflowervol.6790 Před 6 lety +2

    Hello sir. Thank u for the quick reply. Stiochiometry has this sub topics which were not included - eudiometry, limiting reagents, volumetry and Iodometry which we would like to be explained by you sir as you r the only one to keep so simple and to exact point. Hope you will help. Thank you sir.😊

  • @ameennasser5674
    @ameennasser5674 Před 8 lety +17

    if you please explain some mathematics that is mostly in chemistry so that we understand faster
    the fraction part is confusing if you could explain it in easy way that would be wonderful

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Před 7 lety +10

      it's just basic arithmetic, but don't worry, i've got math tutorials coming soon!

  • @yannanini7200
    @yannanini7200 Před 7 lety +2

    hope you'll upload vids about physics too. thank you.

  • @wangyuan8386
    @wangyuan8386 Před 3 lety

    CHEM JESUUUU THANK YOU AMEN

  • @_Dxsk_
    @_Dxsk_ Před 2 měsíci +3

    Thanks Chemistry Jesus

  • @avijidshil2751
    @avijidshil2751 Před 8 měsíci +1

    why did you leave oxygen out of the equation? how does 1 mole of propane give 4 moles of water?

  • @gabriels2395
    @gabriels2395 Před 6 lety +5

    Thank you so much again! So I can say that "mole" is the number of protons (or neutrons) needed to get 1 gram of them. Right?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Před 6 lety +7

      yes that's one way to look at it! technically it's the number of carbon-12 nuclei that will equal 12 grams, but the math works out almost exactly the same.

    • @alderamin1402
      @alderamin1402 Před 2 lety

      I didn't understand what you are saying can you explain it to me

    • @demon_hawkeye5269
      @demon_hawkeye5269 Před 2 lety +1

      @@alderamin1402 I think it's due to the fact that protons and neutrons are almost the same mass so they both count as 1amu, so since moles are amu converted into grams 1mole of protons/neutrons would be 1g

    • @alderamin1402
      @alderamin1402 Před 2 lety

      @@demon_hawkeye5269 yes probably since he /she said just the number of protons I did not get it. thanks but I also really wonder about why 1 amu is equal 1 g. I asked it to my chemistry teacher but she did not know :'''')

    • @demon_hawkeye5269
      @demon_hawkeye5269 Před 2 lety

      @@alderamin1402 it's not that it's equal to 1amu, in fact it's very much the opposite to convert a 1amu neutron to 1g of neutrons you would have to have an avagadro's constant amount of that 1amu neutron, essentially, this is the number of things (be they individual subatomic particles, individual atoms, molecules or whatever else) in one mole of that thing it is 6.02×10^23 this is the same for anything you're trying to get a mole of

  • @villain2715
    @villain2715 Před 3 lety

    Chemistry is so much fun

  • @dionysioschris9405
    @dionysioschris9405 Před 2 měsíci

    Thanks

  • @kashishy538
    @kashishy538 Před 9 měsíci

    Thnks man ..❤

  • @jiinjung1445
    @jiinjung1445 Před 4 lety

    Hi, professor Dave. May I ask you what's sig fig of the last question? I rounded up 20/44 as 0.454 as I thought the sig fig was 3? but it gave me a wrong answer.

    • @DaveGrean
      @DaveGrean Před rokem

      The sig fig are 3, but you rounded wrong. According to my calculator the result is 0,454545... so rounded up it makes 0,455, not 0,454.
      Remember you need to round up from 5 onwards, not 6!

  • @tiffany5333
    @tiffany5333 Před 5 měsíci

    Thank you so much!!!!!1

  • @thej680
    @thej680 Před 7 lety +1

    it took me a while to figure out that you just made up the 20g C3H8 and basically said that C3H8 is 1/4 the moles of water in the product, so you could multiply the 20g of C3H8 to figure out the moles of water. Then you could convert that into grams afterwards. However, is it possible to convert, say we knew the mass in grams of 5O2, into moles of water with the same reasoning that the ratio of moles of oxygen to moles water is 5/4?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Před 7 lety

      yes absolutely! just make sure you convert mass of O2 into moles of O2 first!

  • @priyayadav-wk7bo
    @priyayadav-wk7bo Před 6 lety

    thats awesome

  • @user-tv8ck8bd2g
    @user-tv8ck8bd2g Před 2 lety

    This was an excellent recap for me. I hadn't been in school for nearly a year and was about to dig through my old notes to pick up the basics again. But, I remembered your channel and this video's saved me a lot of hassle. Thanks!

  • @ali_jeez53
    @ali_jeez53 Před 5 lety +1

    I love you so much