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.
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. 👍
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!!!!!
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.
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!
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.
@@ProfessorDaveExplains any recommendations of books about Avogadro and the process of how he developed his equation? Fascinating that he found this number.
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.
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!
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.
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.
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.
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.
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
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!
Oxygen has an atomic mass of about 16 amu. Oxygen's most common elemental form is the O2 molecule. The molecular mass of an O2 molecule is 32 amu. When we consider a mole of oxygen molecules, this means our amu units get promoted directly to grams, because there are by definition 1 mole of amu in 1 gram.
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?
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 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
@@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 :'''')
@@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
رقم افوغادرو 6.022×10²³ رقم ٦ هذا المقصود به كاربون . الكتلة المولية : العنصر × كتلته . C⁶ × 12 . عندما يحصل تفاعل كيميائي العنصر يتغير من جهة اليسار إلى اليمين اي النواتج ، لذلك يجب حساب مول جديد وهذه هي الطريقة : - قبل التفاعل الكيميائي البروبان × عدد المول / الكتلة المولية = المول . - بعد التفاعل الكيميائي المول × عدد المول الجديد / عدد المول القديم او للاختصار : كتلة العنصر • مول ( العنصر ) / الكتلة المستخرجة • العدد الذي بجانب الصيغة مول ( مع العنصر ) / مول الصيغة ( العنصر الثاني ) • غرام الماء / واحد مول ماء = الناتج 20.0 g • 1 mol \ 44.0 g • 4 mol \ 1 mol • 18 g \ 1 mol = 10 g \ 11 g • 4 \ 1 • 18\1 = 40 \ 11 g • 18 \ 1 = رقم / 11 ازلنا جميع g ومول تقريبًا
That's the molar mass of 2-atom oxygen, which is oxygen's elemental form where it is covalently bonded to itself. Unless otherwise specified, oxygen refers to 2-atom oxygen, rather than single atom oxygen (that will seldom exist). Ozone would refer to oxygen's 3-atom form. The same is also the case for any other element that more commonly exists as a 2-atom molecule than a stand-alone atom, such as nitrogen, hydrogen, and any halogen.
I understood in 5 minutes what I couldn't in a whole 2 years of high school... Teachers should just teach things the way you do, it'd be so much easier since you explain everything concisely 😁. They would then just have to answer questions and give a small homework and voilà. Instead, they use a mishmash of terms to "help us understand" when it actually just confuses us more 🙁.
I'm an airline pilot with a BS aeronautics. I never really learned chemistry. I want to return to school and get a masters in nuclear chemical engineering. I'm trying to self-learn as much chemistry and math as I can in these years leading up to my return to school so I can be prepared. Thanks for your videos. I've got a long road ahead.
So you said that 0.455 moles of propane is equal to 1.82 moles of water, but wouldn't you have to add in the moles of the O2 as well? Seeing as you can't make water H20 from just the propane?
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.😊
if one propane molecule produces four water molecules, then one mole of propane molecules will produce four moles of water molecules! it's the stoichiometric ratio of the reaction, which comes from the balanced equation.
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
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
we can say 1kg/2kg = 0.5 . Can we say 1mol ca /1 mol na ? also we need to specify what "mole" we have ? for example does it make sense to say 1 mol or we must specify this mole and say 1 mol of sodium ? also why in gas constant the R constant is just in mol^-1 and not mol^-1 of something ?
I'm not sure I totally understand the question, but no, a mole is just a number unless you specify what you have a mole of, like the word "dozen". In the gas constant there is inverse moles to cancel out moles from the equation, it doesn't need to cancel out the substance itself.
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 ❤️
If given a mass in grams, you divide by the molar mass in g/mol, to get the number of moles. So 72 grams of carbon, would therefore be 72g / (12 g/mol) = 6 moles of carbon atoms. We have grams upstairs, and grams downstairs. We have reciprocal moles downstairs, that get simplified by moving them upstairs. We are left with moles upstairs, and nothing downstairs, thus we have moles as our final units.
Ok thanks. I hope that you fulfill my request. And could you send me the link of the video which you were saying about periodicitiy of properties. Thanks 👍
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?
Right so correct me if i'm wrong In the first example when discussing the Avogadro's number, 1 amu of element * Avogadro's number = 1 mole of element? Pls clarify
![ประสบการณ์ จ้าง Developer ที่ผมจะไม่มีวันลืม [ภาค2]](http://i.ytimg.com/vi/pZbsSDRrmXA/mqdefault.jpg)
Your intro is legendary
And outro also
Telugu Vaaru kada meeru
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.
thanks kindly!
Sir you really maid my day...i finally got interested in Chemistry
Wow never expected to see FSCJ in a comment. Anyway, Go Jags!
@@missishu2431Ain’t no way u said “maid” learn grammar wit yo goofy ahh
I am the real Mole
I knew Jesus was a teacher but i didn't know he taught chemistry
Underrated comment, take my upvote.
Piggintins my chem teach calls him science Jesus
he is NOT jesu:(
I thought Jesus was a car mechanic, because Jesus built my hotrod.
@@fallencity4066 comment up-voting Sophisticated comment about underrated comment , Here take my up-vote
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. 👍
Ys
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!!!!!
Diana Enriquez how’d the test go?
did you pass
@@grantlong7788 sure, passed away
no she ded
ValeStuffs I’ve been summoned from the dead?
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.
Learn More About Analytical Math & How to Think in Abstraction
@@kentheengineer592 Maybe in university. thanks for the recommendation
By simple, you mean words like stoichiometry and stoichiometric.
@@williamconrad1087it’s like Dave saying “for example” rather than saying “For a concrete demonstration of the illustration, we can observe”
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!
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.
thanks, mitch!
@@simoncharlene8947 Thx
Thank you
Which standard you are in
i struggled for a few days, and then soon realized it's just some easy mathematics.
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!
+May C it's my great pleasure! spread the word!
+Professor Dave Explains I sure did! I shared your channel with a few homeschooling Facebook groups in BC, Canada.
@@ProfessorDaveExplains any recommendations of books about Avogadro and the process of how he developed his equation? Fascinating that he found this number.
I have been using his videos to study for midterms
Your the best
I finally get stoichiometry! Thank you so much for this video
Thank you for taking the time to do these videos!
Thank you jesus
I am thing professor Jesus
Keep pushing this VDO , I will go thru all your VDO. Thank you 3 times.
you have saved me
I see what you did there
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.
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!
i wasnt listening in class last time and i have a test, you just saved my ass
So how did the test go
i love being taught by a Foo Fighter
"i've got another confession to make..,"
At 4:01 how do you know there is a 4:1 ratio of propane to water? is it because in the right side of the equation there is a 4 in front of H20?
Yes you have to balance the equation.
@ 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
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.
Thank you for helping. hard to find people like you. I am going to share it. Thanks
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.
It's the molar mass, just use the periodic table.
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
You litterally saved my chemistry GCSE. Thank you so much!
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
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.
Thanks for reminding me, I got 72,8 despite having used a calculator so I was losing my mind, lmao
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.
what's not in this one that you're looking for? it might be in another clip.
I don’t understand this! 3:27
How do you multiply?
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
it's just basic arithmetic, but don't worry, i've got math tutorials coming soon!
thank you for being here. you are the reason i will do well on my exam
i didn't like chemistry till saw your chanel
thank you boss
That's how #ProfessorDaveExplains !
you welcome mr. bossman. glad you sawed chanel
Before I watch this video this lesson made a MASSIVE headache for me.......THANK YOU VERY MUCH PROFESSOR DAVE !
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!
Very easily to understand! Thank you so much 😊 I will watching all of your videos ❤️
saving me from chemistry finals 😂😭
prof dave is a genius. he makes a lesson no brainer.
That was the najd interview yesterday
2:56 You say start with 20g of propane, but when it's added it's 40g. Where did the 20 come from? Thanks
First time I was able to actually understand the reason behind all those calculations. Thanks man!
Thanks for all your chemistry videos
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!
I don’t understand where the 32.0 grams came from can you explain?
Oxygen has an atomic mass of about 16 amu. Oxygen's most common elemental form is the O2 molecule. The molecular mass of an O2 molecule is 32 amu. When we consider a mole of oxygen molecules, this means our amu units get promoted directly to grams, because there are by definition 1 mole of amu in 1 gram.
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?
yes absolutely! just make sure you convert mass of O2 into moles of O2 first!
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?
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.
I didn't understand what you are saying can you explain it to me
@@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
@@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 :'''')
@@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
So you don't account the CO2 when doing stoichiometry?
Thank you Professor Dave. So much learning about your upload videos
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
You: *Clicks on a playlist about chemistry*
"Hey, it's professor Dave. I wanna tell you about moles."
where did 32.0 grams came from???
3:05 how do you get 20g propane?
carbon atomic mass = 16 (6 protons + 6 neutrons) x 3 = 48
+
hydrogen atomic mass = 1 (1 proton) x 8 = 8
= 56 surely?
That's just the mass in the example, not the molar mass of the compound.
at 3:36 why did C3 become 12 x 3?
After watching this video, I am saved THANKS
Amen brother
amen
Bro if you are, stop using him please...his name should always be honored not used
@@user-cy1gs1tl7b gotcha fam my bad
رقم افوغادرو 6.022×10²³
رقم ٦ هذا المقصود به كاربون .
الكتلة المولية : العنصر × كتلته .
C⁶ × 12 .
عندما يحصل تفاعل كيميائي العنصر يتغير من جهة اليسار إلى اليمين اي النواتج ، لذلك يجب حساب مول جديد وهذه هي الطريقة :
- قبل التفاعل الكيميائي
البروبان × عدد المول / الكتلة المولية = المول .
- بعد التفاعل الكيميائي
المول × عدد المول الجديد / عدد المول القديم
او للاختصار :
كتلة العنصر • مول ( العنصر ) / الكتلة المستخرجة • العدد الذي بجانب الصيغة مول ( مع العنصر ) / مول الصيغة ( العنصر الثاني ) • غرام الماء / واحد مول ماء = الناتج
20.0 g • 1 mol \ 44.0 g • 4 mol \ 1 mol • 18 g \ 1 mol =
10 g \ 11 g • 4 \ 1 • 18\1 =
40 \ 11 g • 18 \ 1 = رقم / 11
ازلنا جميع g ومول تقريبًا
i have a question from where did you get 32 in the last comprehension ?
That's the molar mass of 2-atom oxygen, which is oxygen's elemental form where it is covalently bonded to itself. Unless otherwise specified, oxygen refers to 2-atom oxygen, rather than single atom oxygen (that will seldom exist). Ozone would refer to oxygen's 3-atom form. The same is also the case for any other element that more commonly exists as a 2-atom molecule than a stand-alone atom, such as nitrogen, hydrogen, and any halogen.
I understood in 5 minutes what I couldn't in a whole 2 years of high school... Teachers should just teach things the way you do, it'd be so much easier since you explain everything concisely 😁. They would then just have to answer questions and give a small homework and voilà. Instead, they use a mishmash of terms to "help us understand" when it actually just confuses us more 🙁.
This guy is like an alternate universe MoistCr1TiKaL where he studied to become a scientist and a professor.
why did you leave oxygen out of the equation? how does 1 mole of propane give 4 moles of water?
I'm an airline pilot with a BS aeronautics. I never really learned chemistry. I want to return to school and get a masters in nuclear chemical engineering. I'm trying to self-learn as much chemistry and math as I can in these years leading up to my return to school so I can be prepared. Thanks for your videos. I've got a long road ahead.
So you said that 0.455 moles of propane is equal to 1.82 moles of water, but wouldn't you have to add in the moles of the O2 as well? Seeing as you can't make water H20 from just the propane?
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.😊
limiting reagents has its own clip so definitely check that one out. the other words i've never even heard of!
Ok sir.
@@sunflowervol.6790you are definitely indian
You are a gift from God, ... would you mind doing more o-chem videos?!
Watching 2 hours before deadline!! Thank youuu
thanks so much! you got a new subscriber
Your videos are Nuklary. Good job
2:50
Why is this composition reaction not displacement reaction?
Thank you for the video. I am grateful for your time and contribution. Kind regards, Akira.
Thank you professor dave 😇
So what is the more accurate precise answer 32.8 or 32.7?
where do we get the 20g from at 3:28?
Bro is about to measure the amount of alcohol molecules that he's going to turn his glass of water into.
Your teaching is great
How did you get that 4 moles of H20 is equal to 1 mole of C3H8? You said they were in a 4:1 ratio, but I'm not sure how you got that ration. Thanks :)
I see that you are using the coefficients, but I don't get why coefficients put them in a ratio
if one propane molecule produces four water molecules, then one mole of propane molecules will produce four moles of water molecules! it's the stoichiometric ratio of the reaction, which comes from the balanced equation.
where did you get the 18.0 g H20? Thank you.
molar mass of water
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
Where did that 4:1 ratio come from?
stoichiometric coefficients
So am I right: x atomic units · y moles = xy grams .
Great video, David!
Can you please add subtitles on your videos? it will help us a lot to understand the concept more clearly.
All the videos have subtitles.
@@ProfessorDaveExplains💀
Legend has it that those who dislike his
videos will never understand chemistry ever again...
take my upvote!
Thank you! I am in fourth grade and now I am really ahead
kind of..
I wonder professor David what is stoichiometric point.Could you explain me?
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
we can say 1kg/2kg = 0.5 . Can we say 1mol ca /1 mol na ? also we need to specify what "mole" we have ? for example does it make sense to say 1 mol or we must specify this mole and say 1 mol of sodium ? also why in gas constant the R constant is just in mol^-1 and not mol^-1 of something ?
I'm not sure I totally understand the question, but no, a mole is just a number unless you specify what you have a mole of, like the word "dozen". In the gas constant there is inverse moles to cancel out moles from the equation, it doesn't need to cancel out the substance itself.
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 ❤️
With a botox jab?😂
I still don't understand how you got the 18g of H2O at 4:40. Can you please explain it again?
O has a mass of 16, H has a mass of 1, two H's and one O = 18
@@ProfessorDaveExplains oh that was easy! thank you so much. I love how your videos because you cover the whole topic very quickly and efficently!
i was wondering where did you get the 20.0g in the 4:22?
given information
@@ProfessorDaveExplains thank you! your videos help me in my chemistry class
@@ydelmaeselda402 same problem for me but I just watched one more time with captions
The molar mass is measured in g/Mol so if I multiply by Mol/(g/mol) the unit will be mol^2 not mole
If given a mass in grams, you divide by the molar mass in g/mol, to get the number of moles.
So 72 grams of carbon, would therefore be 72g / (12 g/mol) = 6 moles of carbon atoms. We have grams upstairs, and grams downstairs. We have reciprocal moles downstairs, that get simplified by moving them upstairs. We are left with moles upstairs, and nothing downstairs, thus we have moles as our final units.
Your explains is more than great Mr Dave👏👍
It would be better if you explain Maths too. And please upload a video about Periodicity of properties
friend, i did one on periodic trends! check it out. and math should be coming some time next year.
Ok thanks. I hope that you fulfill my request. And could you send me the link of the video which you were saying about periodicitiy of properties. Thanks 👍
th-cam.com/video/hePb00CqvP0/w-d-xo.html
Thanks prof
hope you'll upload vids about physics too. thank you.
those are coming before the end of the year!
Thank you. I'll look forward to it.
Thank u for this tutorial.. its very helpful..
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?
Professor Dave! Thank you!
Thx 4 the vid
Right so correct me if i'm wrong
In the first example when discussing the Avogadro's number,
1 amu of element * Avogadro's number = 1 mole of element?
Pls clarify
not exactly, it's one object times avogadro's number equals a mole of that object, and that can apply to atoms, or anything else
@@ProfessorDaveExplains ohhhh
so moles aren't an element exclusive measurement
thanks professor dave!
Can we use O2 to find how many moles of water there is?
Does everything have to be over something? We were just taught the equation: moles=mass/Mr
This is a conversion factor
is 0.5 mole of chromium (III) oxide (Cr2O3) the same as 0.5 mole of Cr+ ions and 0.5 mole of O- ions? or how does it work?
well there are two chromium ions per formula unit, so double it!