The Mole: Avogadro's Number and Stoichiometry

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.
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Your intro is legendary

[@IITJEEADVANCEXD]

And outro also

[@sirishavejendla4156]

Telugu Vaaru kada meeru

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

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Underrated comment, take my upvote.

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

[@elmerlopez4146]

Piggintins my chem teach calls him science Jesus

[@grantlong7788]

he is NOT jesu:(

[@marktaylor7162]

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

[@matthewcecil8552]

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]

thanks kindly!

[@missishu2431]

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

[@tonybatycki]

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

[@josiahwhite3157]

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

[@MoleLife-mn9bq]

I am the real Mole

[@Fjuron]

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. 👍

[@zucchini9177]

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!!!!!

[@jamesmanning8269]

Diana Enriquez how’d the test go?

[@grantlong7788]

did you pass

[@RandomPerson-hd9sb]

@@grantlong7788 sure, passed away

[@valestuffs]

no she ded

[@zucchini9177]

ValeStuffs I’ve been summoned from the dead?

[@mitchyboy41]

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]

thanks, mitch!

[@misfire32]

@@simoncharlene8947 Thx

[@megajihamsikaa]

Thank you

[@real_GANGSTA_]

Which standard you are in

[@SCP--mw7tx]

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

[@freedomofspeech122]

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]

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

[@freedomofspeech122]

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

[@tonybatycki]

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

[@xdanx01]

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

[@charlieann8661]

Thank you for taking the time to do these videos!

[@kent7966]

I have been using his videos to study for midterms

[@roysolomon4755]

Your the best

[@expiredflunky5603]

Thank you jesus

[@sreevivasaraghavan6848]

I am thing professor Jesus

[@doremi1414]

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]

Learn More About Analytical Math & How to Think in Abstraction

[@doremi1414]

@@kentheengineer592 Maybe in university. thanks for the recommendation

[@williamconrad1087]

By simple, you mean words like stoichiometry and stoichiometric.

[@TenNineD]

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

[@austinsporn8432]

you have saved me

[@wilts8965]

I see what you did there

[@titidechdamrongwut1351]

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

[@christinayang2658]

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!

[@---fb6zs]

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

[@sarayhazuki4709]

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!

[@edwintafalla589]

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

[@OIOTV-zo9qp]

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

[@ajibolakehindeaishat5892]

Thanks for all your chemistry videos

[@stu_0618]

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

[@saitejamandiga2916]

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

[@gbmsg282]

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

[@HenriFaust]

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?

[@user-ww3pf4cr8c]

Your explains is more than great Mr Dave👏👍

[@veryhealthy9962]

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!

[@sunflowervol.6790]

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]

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

[@angeliemaebonaobra4448]

Professor Dave! Thank you!

[@akira_asahi]

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

[@jimbynumsierravistahs2319]

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.

[@praviinashanbalagan1563]

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]

Thank you professor ! It helped me alot.

[@jackmorvan813]

Great video, David!

[@mychaelpierce8049]

Great video. Thanks for sharing!

[@zeinabmuhammed4549]

Thank you professor dave 😇

[@jacquelineoonzhien3234]

Thank you so much for the video!

[@GriteKidsTV]

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

[@chiklachikla7641]

So how did the test go

[@alexandrashields2600]

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

[@cardiyansane1414]

@ 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

[@inoxide5454]

i love being taught by a Foo Fighter

[@richardtriance5207]

"i've got another confession to make..,"

[@mickjay7397]

1 mole of anything in this universe is 6.02x10^23 .. To make comparison between different substances this method provides a standardized approach It's like saying you measure gold in carats. To know the strength of gold you use carats as way to understand how pure that ring or jewelry is. It's same with atoms and molecules. To know the amount available in a mixture we use moles as a number to have a standard for calculating things.

[@connerbrandy9185]

Thank you, Helped a lot!!

[@MARTZX1111]

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

[@maesie_alexa4084]

Watching 2 hours before deadline!! Thank youuu

[@priovag2632]

Your teaching is great

[@dominicnikon6276]

Awesome video thank you so much

[@socceralex12345]

Thx 4 the vid

[@jzzh1]

thanks so much! you got a new subscriber

[@madylinn9235]

Thanks prof

[@steezyspamsl223]

saving me from chemistry finals 😂😭

[@jimjimmy3131]

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.

[@callumalmighty]

Nice one Dave!

[@Roy-mk9zl]

Thanks sir.

[@k_Why]

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

[@linaberkani309]

Thank you sooooo muuuuch

[@study4life443]

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]

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

[@spitfire184]

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

[@ameennasser5674]

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]

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

[@ammyvl1]

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

[@old-tech]

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]

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

[@triple_gem_shining]

literally love dave

[@ansumann]

Thank you so much

[@universal6906]

Thanks for You clear my dought

[@just7815]

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

[@Dragon-Slay3r]

That was the najd interview yesterday

[@Dg-ii5xk]

Thanks a lot!

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Thank you

[@ameennasser5674]

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

[@lakshminarasimhamurthyvish9204]

That's how #ProfessorDaveExplains !

[@grantlong7788]

you welcome mr. bossman. glad you sawed chanel

[@arway4766]

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

[@incrediblestudios5609]

I love you Professor Dave

[@sskybluezen]

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

[@NeuronalAxon]

How'd it go?

[@avijidshil2751]

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

[@newone8463]

Thank you 'awesome' broh

[@irenecuartocruz6371]

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

[@jhelseaamarixe4475]

hi how many decimal places do i have to consider if it's already repeating

[@alderamin1402]

THANKS

[@ciaranlonergan9910]

Love you Dave

[@franzliszt204]

Thanks

[@AmarSingh-xf8di]

good video of chemestry

[@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 ❤️

[@Dragon-Slay3r]

With a botox jab?😂

[@narniansworld9735]

Thank you sir ❤️🙏🙏

[@ThingsOut]

I don’t understand this! 3:27 How do you multiply?

[@sunflowervol.6790]

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.😊

[@ProfessorDaveExplains]

limiting reagents has its own clip so definitely check that one out. the other words i've never even heard of!

[@sunflowervol.6790]

Ok sir.

[@hshsndjd2845]

​@@sunflowervol.6790you are definitely indian

[@Dragon-Slay3r]

Ive already been stung there 😂

[@bilimAdimlari]

you're good teacher

[@peterclancy3653]

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!

[@yannanini7200]

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

[@ProfessorDaveExplains]

those are coming before the end of the year!

[@yannanini7200]

Thank you. I'll look forward to it.

[@rishabb.8476]

stilll need to do

[@EpicSchizophrenium]

So If I would know how many Mols of O2 I have than would I have 4/5 of a mole of Water because the ratio is 4/5

[@loshithasahan7164]

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

[@gabriels2395]

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]

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]

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

[@demon_hawkeye5269]

@@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]

@@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]

@@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

[@jobekirkuk]

Your videos are Nuklary. Good job

[@MsAsh496]

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

[@thej680]

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]

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

[@fallennarcotic6981]

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?

[@yigitcanbaysal824]

I wonder professor David what is stoichiometric point.Could you explain me?

[@tiffany5333]

Thank you so much!!!!!1

[@nelson138]

In the comprehension section I get 72 gm , it says 72.7 grams . I'm multiplying 2.25 moles of O2 by 32.0 grams O2 and that gives me 72 grams of O2,Am I wrong?

[@kashishy538]

Thnks man ..❤

[@andrixleenocaspe3573]

So you don't account the CO2 when doing stoichiometry?

[@oluwatosinoluwafemi6331]

You are so wonderful !

[@user-tv8ck8bd2g]

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!