I calculated the volume of a mole of 1 inch spheres. It was rather mind blowing. One side of a cube (a mole) of 1 inch spheres will extend from Capitola, CA to Chicago, IL The results were illustrative of how tiny atoms really are and how big, 10^23, really is.
Are you sure you did the homework right? That distance you mentioned according to Google is 3500km = 3.5*10^8, in inches (your damn imperial system, you should really leave that behind...) Makes it around 1.4*10^8, so we are missing many many orders of magnitude...
If we substitute the one inch sphere for a 40mm sphere, then a regulation table tennis ball (ping pong ball) is a convenient representation. So an avogardro number of table tennis balls would exceed the current annual production of balls multiplied by the approximate age of the earth. By many orders of magnitude. This would not be well received by the IOC or China. Such a shame. K.
Great video! The uncanny thing is that over the last few days, I've been thinking about Avogadro's number and wish I had understood this in high school, and "Bam!" TH-cam algorithm suggests your video to me. Pretty wild. I haven't searched for it. Merely thought about it.
nice video, i almost got kinda lost with the sodium, calculation, cause we say Natrium, or cause i am a little untalented with the subject, but thanks to your and so many other nice videos, ill get it.
This is the sort of thing that I had trouble with in school. Why does one mole of oxygen plus two hydrogen make two water? Where does the extra volume go? Energy?
it doesn't make two volumes of liquid water, it makes two volumes of water vapour. it's because, assuming they're at the same temperature and pressure, the same number of molecules of gases occupy the same volume. 2 litres of H2 and 1 litre of O2 turn into 2 litres of H2O. what stays the same is the total number of atoms. but they're arranged in fewer molecules, so they occupy a smaller volume. that assumes the pressure and temperature are maintained.
More questions arise when you explain the ballon example. Gay-Lussac was able to demonstrate the 2 + 1 ratio of gases were combining to H2O, but before that Lavoisier was able to make experiments with gases in glass-tube systems, as far as I remember, and that sounds like magic until you get to know a bit more about the crafts at that time, they could make all sorts of glass containers. In itself an astonishing feat! So far I have not found any textbook explaining exactly how easy/difficult those experiments were. if you use water in a gas piping system to equalize the pressure to atmospheric pressure, then oxygen will dissolve in the water and the experiments will be unsuccessful. But if you use mercury you will probably be able to avoid solutions or other reactions, right?
It has always made my head spinning, seriously, when an explanation rises more questions than it solves. That is why I ask. I love your videos and will continue to find answers. ❤
Hey best professor can you make a video teaching band gap or detailed look of semiconductors. Thank you for the effort for making such priceless videos .
I have noticed in more than one video you avoid mentioning where the number seemengly come from... I understand the mole being the number if atoms in 12g of C12 us not the most accurate thing, but is there a reason in particular to avoid this definition? I was 'raised' in chemistry with this 😄
Hmmm, I understand how you determine a mole of a molecule by weight, but clearly you can’t weigh out a mole of photons, how do you determine a mole of a massless particle?
This mole shit was troubling me for age... because of my illiterate chem teacher in my 9&10th grade.....how the hell they can be so dumb not to give this same example for starters and i was the brightest in my chem..... Thax mate for making mole go away from my back 😂
The term "mole" to mean a large number IS related to the small burrowing mammal . Moles (the small mammals) make piles due to their digging hence the saying " Mountains Out Of Mole Hills. I suspect the etymology you cited used the burrowing small mammal association with making piles . This might be an analogy to " How Many Angel's Can Dance On The Head Of A Pin ? " 😅
The key idea that seems to be left out is that in a gas the molecules are so spaced apart that effectively any molecule in a gas takes up the same proportionate amount of "space". E.g., a penny in a stadium and a quarter in a stadium both take up the same "space" if we are only comparing the stadium and how much it's space takes up in a convenient. This means that for gasses, for all practical purposes every (gas) molecule has the same size as every other and so we simplify everything down to pretending there is only one type of gas molecule. This then allows you to do a direct comparison among molecules because if they take up the same "volume" then you can assume they have the same number. This then lets you ignore the number and pretend you are just working with single molecules which lets you do stoichiometry(which the video does talk about. But one has to understand that the space around a molecule of hydrogen and a molecule of oxygen is the "same" space and can be treated as "point particles". Once one can do that then the number is directly related to the volume and one can use the volume to compare numbers(hence leading to stoichiometry). With enough measurements one could eventually use volume relationships to determine molecule relationships in various reactions and then deduce atomic relationships in molecules. Of course there is no reason to necessarily use volume which may be difficult to measure in some cases but transfer that to pressure calculations. Of course once one starts understanding how molecules compose in volume relationships then one starts to understand how they "react" and one can start to understand the molecular substructural relationships.
@MDNQ-ud1ty wonderful explanation out there! But considering each atom has different atomic radii(impies their sizes are different) how one can conclude that " every (gas) molecule has the same size as every other "?
@@assassin4737 Because the gas is typically homogeneous. That is, it is all of the same molecule. Typically when you speak of a gas it is of a singular type of molecule/atom and not a mix. The basic idea, if I recall everything correctly(it's been a year), is pretty simple in that one has a repeating "unit" and so one can do basic calculations on that unit. It's just math. Even if one has a heterogeneous structure, it will just,essentially, change things in some proportion so everything works out mathematically except for some scale factor which one could correct for once they understand the basic compositional structure. E.g., if you have n atoms and m other atoms in a gas one can assume they are equally distributed and one can do some basic calculation assuming either one has all of one, all of the other, or in some proportion. No matter how wrong you are you will eventually be able to correct for any miscalculations by a simple multiplier that you can derive using more precise measurements in determining the proportions. This is because at the end of the day you are doing a calculation that is n*x + m*y or whatever and n and m are found just integrating over a space. Since the integral is linear and so is the distribution it is essentially something that grows linearly in terms of the "size" you take. E.g., if you double the size of the container you double the amount irrespective of what it contains(because it is homogeneous because that is how gasses work. One can't do this necessarily for a liquid or solid). That is, once you have found your proper "unit"(your fundamental structure that is repeated) then it is just all "linear math" which has specific implications. Then any errors in your unit(e.g., if you measure it to be too large or small) can be converted by just multiplying by a conversion factor. In some sense, what is really being measured is the space and not the specifics of the representation of that space through atoms. E.g., imagine you are trying to compute a volume in space. You could use unit balls, cubes, or stars or blobs and all will give you various estimates of the volume. When you take the limit you will get precise estimates but they will all be different depending on the relation between the units(a cube to a ball(e..g, 4/3pi), etc). The point is that it may seem complicated when one looks at it "inside the unit"(all the complexity of atoms and molecules) but when you are outside(zoom out) you are just dealing with "points". The gas, effectively, on average, can be thought of as a lattice structure. E.g., think of an actual homogeneous solid that is spaced equally in 3 directions(cubical). E.g., suppose you have oxygen and nitrogen("air") as a gas in some proportion(say 20/80). You can then mathemagically just abstract that to a new "atom" that has 20% of O and 80% of N. It doesn't matter how they are arranged as long as as a "building block" it is repeated consistently. Even when the units are flying around in random directions it won't matter because as long as you can treat it as if it were simple then you can get away with doing these things. [E.g., on average the gas is not moving at all(because it's in a container and so you can just pretend they are immobile and equally spaced). Then, and IIRC, this is the key point. One is not really assuming every molecule is the same to every other but their exact differences are going to express themselves exactly in the concept of a mole. 1 Mole of X is 1 Mole of Y but they will have different atomic masses, different weights etc. Then the differences are precisely the differences in their "shapes"(e.g., back to the cube vs ball vs blob). That is, we simply say we have 1 Mole of the basic unit. E.g., 1 Mole of U$D. That has a certain value. Then 1 Mole of JPY has a certain value. The "conversion factor" is what translates and relates one to the other. It's approaching it from a different perspective because of the way atoms interact. We don't care so much about their shapes but their number relationships. E.g., H2O is a very complex but fundamentally it is a 2:1 relationship and chemistry is about these relationships working out(and essentially it is just linear algebra). Think of the sticks and balls model. Each ball can take a fixed amount of sticks. If you have some model and it has N sticks and M balls then if you have K of these models you know you have K*N sticks and K*M balls. It doesn't matter how they are arranged or even if they are connected up or what. But you assume a certain "repetition of structure" then you are forced into certain mathematical relationships. E.g., if you have 2 balls who can only have 2 connected sticks to them then you can't have 435 sticks. You can only have 0, 1, or 2. So the key idea is that when you do these large scale reactions(because that is all that can be done since you can't work at a single atomic level) you can, with a few logical assumptions, work things out so it is as if you can work at the single level because it is just a "scaling problem". When you work in moles it is just working with the # of units. If you work in mass or weight you are essentially comparing apples to oranges. It literally takes 2 moles of hydrogen and 1 mole of oxygen to create 1 mole of H2O. It's also true of any scaling of that. If we work with 1 gram of hydrogen and 1 gram of oxygen then we have problems. The math no longer is simple. I have no idea how many grams of H2O will be produced by that. We will have something left over. So moles scales all the units properly so we can use them in chemistry in the way that they actually work(which is "pairing off" and little to do with their actual structure). E.g., we can just define 1 mole of anything to be N of those things. As long as how we combine those things only depends on quantity then it all will work out(we then just need to figure out how to convert between that representation and other representations used(mass) which are better for other purposes). E.g., if we have 1 mole of TV's and 1 mole of houses then that gives us 1 mole of houses with TV's. If we were talking about masses then it would be a much more complex problem(but not too difficult if all the TV's and houses weighed the same). So the language of moles abstracts out the issues to pure quantity which along with other rules of how exactly different things can combine(the "laws of chemistry") gives us simple ways to work with chemical equations. Basically it factors out the "combinatorics" side of the problem into a nice useful idea. It's nothing special but it is convenient.
Loved the insights! You gave me much more than what i had asked! PS:" If we work with 1 gram of hydrogen and 1 gram of oxygen then we have problems. The math no longer is simple. I have no idea how many grams of H2O will be produced by that. We will have something left over." I think 0.5 moles of oxygen will be left unreacted.
@@assassin4737 No, because you have to convert those grams to moles. Reactions are combinatorical. That is, atoms and molecules react in terms of quantities and nothing else. It's "Number theory". That is, you can't attach half a hydrogen to an oxygen. So you have to work in numbers of atoms rather than their masses. So you need to know how many atoms of hydrogen exist in 1g of it. Since oxygen is essentially 16 times larger(it contains 8 protons but also around 8 neutrons) then 1gram of oxygen will be about 1/16th the size. e.g., if you put 1g of hydrogen on the scale and 1g of oxygen on it and then counted the atoms you will have about 16 times fewer. So, in fact, for every 16 hydrogen we have 1 oxygen. Now we need 2 hydrogen and one oxygen to form water. But we have 16 hydrogens for one oxygen(we only need 2). What this means is that we will use up all our 1 gram of oxygen very quickly and have a lot of hydrogen left over. That is, we will have 14 left over. This means, in proportion, 14/16 = 7/8 of the hydrogen will not be used. Or 7/8 of 1g will not be used. That is, we will have 7/8g of hydrogen left over. So, in fact, we will have all the oxygen reacted(because all it needs is 2 hydrogen per oxygen but we have 16 per oxygen). That is, 1g of hydrogen has 16 times the number of hydrogen. So if there are N oxygen atoms in the 1g of oxygen we have 16*N hydrogen atoms. If we just look, as I have been doing, at one specific reaction. That is, we pretend N = 1, then we have 16 hydrogen and 1 oxygen. After the reaction we have 14 hydrogen and one H2O. So we have 14 hydrogen left over that can't react because there is no more oxygen left to react. So, if you wanted to have a complete reaction you would need 1/16th of a gram of hydrogen and 1g of oxygen. Or 16g of hydrogen and 1g of oxygen. The entire point of the mole is to get away from having to deal with the mass of things because then we have to know the mass relationships(which is actually more complex due to isotopes). A mole "normalizes" things so we only are talking about numbers of atoms. Then it is easy. We know we just need 2 H and 1 O. We don't have to do any conversion. Think about it like this: Suppose we have a "mole" weighing scale. It can weigh out moles. We put some hydrogen on it and it says: You have 2 moles of hydrogen. Great!. We put some oxygen on it(after removing the hydrogen of course) and it says: You've got 1 mole of oxygen. Even better. Now if we stick those two amounts together we will have 1 mole of H2O. It's 1 mole because we are talking about a unit of H2O. But 2 + 1 != 1. If we use add 1 gram of hydrogen, 1 gram of oxygen, we get 2 grams of hydrogen and oxygen and water. More specifically, we get 7/8 H + 0*O + 9/8*H2O. Here 7/8 + 0 + 9/8 = 16/8 = 2g. We started with 2 grams of stuff and ended up with 2 grams of stuff(but different types of stuff) Basically if we are going to use mass in our reaction calculations we have to know the individual atomic mass relationships. If we use moles we don't have to know any of that. Chemical reactions essentially do not care about mass and they only care about number.
When chemists mix chemicals, the molecules they're trying to make hava a certain number of each kind of atom. So you need to mix two molecules of this with one molecule of that, and so on. So you want to know a weight of each kind of chemical that's proportional to the number of molecules in it. Surely that's really simple.
I had a question - Why do we even need the concept of a mole? We can just make a chart of number of atoms per gram of every element and use that as an index? What is benefit of EVEN needing the mole or having the avogadros number?
I'd say it's why Ohm Law, V=IR, isn't Seimen's Law V = I/G. (G is conductance). Using atoms per gram involves inverse mass per atom and no one want's that. Also: N_A sets the scale from microscopic to macroscopic, which is nice. Just like "c" sets the speed scale for Galileo vs Einstein, hbar sets the action scale for classical vs quantum, G (/c^4) sets the scale for Newton vs Einstein, and finally k_B sets the scale at which thermodynamics works (e.g. exact knowledge of phase space vs macroscopic averages).
@@DrDeuteron Hmm, makes sense. Its not so much science, but more about convenience then. I guess THAT should be highlighted when it is taught in school, so we know why AN is a benchmark. I guess it is like light year, it gives an idea of not just distance but time as well and convenient for extremely large distances.
which is 18g of H20 per grain or 18 ml per grain which the chemist-chef would say is a bit much as the dish of rice would be soggy or does each grain of rice contain 6.02214x10exp 23 molecules of stuff then we have a 1:1 ratio. @@fukpoeslaw3613
I got headache when you say 2 units of water and add "vapor" in writing. Water vapor, at temperature 0⁰C isn't something I can grasp easily, ig makes me think ice-water, Arctis, how can I avoid that vapor will condense? And such. 🤔➕️🔜↪️⏩️⚡️😇
A mole is needed to convert the weights of atoms or molecules in amus to their conglomerate weight in grams.... End of explanation. If it were not for the Chemistry of Gasses, we might not have 10% of the Understanding of reality that we have today.
This isnt for beginners! - never heard of Zealites. I endured a "chemistry education - 1959 _- 1964, & passd O level GCE . . Why break down Butane - a useful industrial gas, into Methane - a nuisance greenhouse gas? You lost me when talkin about Sulphites!
You are the best teacher. Trust me!
Thank you, that's very kind.
I calculated the volume of a mole of 1 inch spheres. It was rather mind blowing. One side of a cube (a mole) of 1 inch spheres will extend from Capitola, CA to Chicago, IL The results were illustrative of how tiny atoms really are and how big, 10^23, really is.
Are you sure you did the homework right? That distance you mentioned according to Google is 3500km = 3.5*10^8, in inches (your damn imperial system, you should really leave that behind...) Makes it around 1.4*10^8, so we are missing many many orders of magnitude...
@@Earthstorm84 a cube with side 3.5e8 inch will have volume of about 3e25 inch
@@ivoivanov7407 I missed the cube part I thought he was just lining up the molecule to make a distance 😄
If we substitute the one inch sphere for a 40mm sphere, then a regulation table tennis ball (ping pong ball) is a convenient representation. So an avogardro number of table tennis balls would exceed the current annual production of balls multiplied by the approximate age of the earth.
By many orders of magnitude.
This would not be well received by the IOC or China.
Such a shame.
K.
Very well done. Great approach to teaching the basics of the history of chemistry, and how it works.
In the game Godville, my character has a pet “vengeful mole” that I named Avogadro. Another character had one that I named “Guaca.”
Other than Periodic Videos, your content is the only other chemistry channel that is fun to watch ❤🎉
Great video! The uncanny thing is that over the last few days, I've been thinking about Avogadro's number and wish I had understood this in high school, and "Bam!" TH-cam algorithm suggests your video to me. Pretty wild. I haven't searched for it. Merely thought about it.
Thought implantation...telepathy...algorithm/telepathy receiver...
8:36 22.4 litre to be precise.
can u explain why one mole has 23 l of something only?
Nice video, but I had to say the skit was pretty fun. Didn’t expect how the video ended! Bravo
Glad you enjoyed it!
Thanks you for this such pedagogic video. It's wonderful to be able to understand the world around us trough this knowledge !
This has been a very educational video, thanks for explaining this.
I knew moles were involved, great film !
nice video, i almost got kinda lost with the sodium, calculation, cause we say Natrium, or cause i am a little untalented with the subject, but thanks to your and so many other nice videos, ill get it.
My god that’s outstanding! Subscribed
Thanks for the detail.
As always, u amaze and amuse me. I'm SO SO into chemistry bcs of u.
Great video - and I just loved the skit! Set the moles free! LOL!
This is the sort of thing that I had trouble with in school. Why does one mole of oxygen plus two hydrogen make two water? Where does the extra volume go? Energy?
it doesn't make two volumes of liquid water, it makes two volumes of water vapour. it's because, assuming they're at the same temperature and pressure, the same number of molecules of gases occupy the same volume.
2 litres of H2 and 1 litre of O2 turn into 2 litres of H2O. what stays the same is the total number of atoms. but they're arranged in fewer molecules, so they occupy a smaller volume. that assumes the pressure and temperature are maintained.
@@MusicalRaichu thanks for the explanation
My best teacher
Excellent opening skit!
That's a perfect explanation, thank you!
Fun fact. We in Europe measure rice in grams (instead of cups), just like if we were all chemists.
Smart, not fun.
Everyone knows how is so much accurate measuring something in weight than in volume. Even more when you are dealing with a solid.
There are two types of countries... 😂
@@FelonyVideos This myth was already debunked. NASA used SI units for Apollo missions.
More questions arise when you explain the ballon example. Gay-Lussac was able to demonstrate the 2 + 1 ratio of gases were combining to H2O, but before that Lavoisier was able to make experiments with gases in glass-tube systems, as far as I remember, and that sounds like magic until you get to know a bit more about the crafts at that time, they could make all sorts of glass containers. In itself an astonishing feat! So far I have not found any textbook explaining exactly how easy/difficult those experiments were.
if you use water in a gas piping system to equalize the pressure to atmospheric pressure, then oxygen will dissolve in the water and the experiments will be unsuccessful.
But if you use mercury you will probably be able to avoid solutions or other reactions, right?
It has always made my head spinning, seriously, when an explanation rises more questions than it solves. That is why I ask. I love your videos and will continue to find answers. ❤
Well explained, I’m a little closer thanks
Hey best professor can you make a video teaching band gap or detailed look of semiconductors. Thank you for the effort for making such priceless videos .
It's the constant by which conservation of mass is maintained
most interesting this formula spills over into weather chemistry. Is it the basis of C.A.P.E.?
You should make more videos.... 🎩 ❤❤❤
13:37 Water* ❤
I have noticed in more than one video you avoid mentioning where the number seemengly come from... I understand the mole being the number if atoms in 12g of C12 us not the most accurate thing, but is there a reason in particular to avoid this definition? I was 'raised' in chemistry with this 😄
Nice explanation.. kindly upload lecture on reaction mechanism in organic chemistry
Hmmm, I understand how you determine a mole of a molecule by weight, but clearly you can’t weigh out a mole of photons, how do you determine a mole of a massless particle?
This mole shit was troubling me for age... because of my illiterate chem teacher in my 9&10th grade.....how the hell they can be so dumb not to give this same example for starters and i was the brightest in my chem..... Thax mate for making mole go away from my back 😂
The term "mole" to mean a large number IS related to the small burrowing mammal . Moles (the small mammals) make piles due to their digging hence the saying " Mountains Out Of Mole Hills. I suspect the etymology you cited used the burrowing small mammal association with making piles . This might be an analogy to " How Many Angel's Can Dance On The Head Of A Pin ? " 😅
The key idea that seems to be left out is that in a gas the molecules are so spaced apart that effectively any molecule in a gas takes up the same proportionate amount of "space". E.g., a penny in a stadium and a quarter in a stadium both take up the same "space" if we are only comparing the stadium and how much it's space takes up in a convenient. This means that for gasses, for all practical purposes every (gas) molecule has the same size as every other and so we simplify everything down to pretending there is only one type of gas molecule. This then allows you to do a direct comparison among molecules because if they take up the same "volume" then you can assume they have the same number. This then lets you ignore the number and pretend you are just working with single molecules which lets you do stoichiometry(which the video does talk about. But one has to understand that the space around a molecule of hydrogen and a molecule of oxygen is the "same" space and can be treated as "point particles". Once one can do that then the number is directly related to the volume and one can use the volume to compare numbers(hence leading to stoichiometry). With enough measurements one could eventually use volume relationships to determine molecule relationships in various reactions and then deduce atomic relationships in molecules. Of course there is no reason to necessarily use volume which may be difficult to measure in some cases but transfer that to pressure calculations. Of course once one starts understanding how molecules compose in volume relationships then one starts to understand how they "react" and one can start to understand the molecular substructural relationships.
@MDNQ-ud1ty
wonderful explanation out there!
But considering each atom has different atomic radii(impies their sizes are different)
how one can conclude that " every (gas) molecule has the same size as every other "?
@@assassin4737
Because the gas is typically homogeneous. That is, it is all of the same molecule. Typically when you speak of a gas it is of a singular type of molecule/atom and not a mix.
The basic idea, if I recall everything correctly(it's been a year), is pretty simple in that one has a repeating "unit" and so one can do basic calculations on that unit. It's just math.
Even if one has a heterogeneous structure, it will just,essentially, change things in some proportion so everything works out mathematically except for some scale factor which one could correct for once they understand the basic compositional structure.
E.g., if you have n atoms and m other atoms in a gas one can assume they are equally distributed and one can do some basic calculation assuming either one has all of one, all of the other, or in some proportion.
No matter how wrong you are you will eventually be able to correct for any miscalculations by a simple multiplier that you can derive using more precise measurements in determining the proportions.
This is because at the end of the day you are doing a calculation that is n*x + m*y or whatever and n and m are found just integrating over a space.
Since the integral is linear and so is the distribution it is essentially something that grows linearly in terms of the "size" you take. E.g., if you double the size of the container you double the amount irrespective of what it contains(because it is homogeneous because that is how gasses work. One can't do this necessarily for a liquid or solid).
That is, once you have found your proper "unit"(your fundamental structure that is repeated) then it is just all "linear math" which has specific implications.
Then any errors in your unit(e.g., if you measure it to be too large or small) can be converted by just multiplying by a conversion factor.
In some sense, what is really being measured is the space and not the specifics of the representation of that space through atoms.
E.g., imagine you are trying to compute a volume in space. You could use unit balls, cubes, or stars or blobs and all will give you various estimates of the volume. When you take the limit you will get precise estimates but they will all be different depending on the relation between the units(a cube to a ball(e..g, 4/3pi), etc).
The point is that it may seem complicated when one looks at it "inside the unit"(all the complexity of atoms and molecules) but when you are outside(zoom out) you are just dealing with "points".
The gas, effectively, on average, can be thought of as a lattice structure. E.g., think of an actual homogeneous solid that is spaced equally in 3 directions(cubical).
E.g., suppose you have oxygen and nitrogen("air") as a gas in some proportion(say 20/80). You can then mathemagically just abstract that to a new "atom" that has 20% of O and 80% of N. It doesn't matter how they are arranged as long as as a "building block" it is repeated consistently. Even when the units are flying around in random directions it won't matter because as long as you can treat it as if it were simple then you can get away with doing these things. [E.g., on average the gas is not moving at all(because it's in a container and so you can just pretend they are immobile and equally spaced).
Then, and IIRC, this is the key point. One is not really assuming every molecule is the same to every other but their exact differences are going to express themselves exactly in the concept of a mole. 1 Mole of X is 1 Mole of Y but they will have different atomic masses, different weights etc.
Then the differences are precisely the differences in their "shapes"(e.g., back to the cube vs ball vs blob).
That is, we simply say we have 1 Mole of the basic unit. E.g., 1 Mole of U$D. That has a certain value. Then 1 Mole of JPY has a certain value. The "conversion factor" is what translates and relates one to the other.
It's approaching it from a different perspective because of the way atoms interact. We don't care so much about their shapes but their number relationships. E.g., H2O is a very complex but fundamentally it is a 2:1 relationship and chemistry is about these relationships working out(and essentially it is just linear algebra).
Think of the sticks and balls model. Each ball can take a fixed amount of sticks. If you have some model and it has N sticks and M balls then if you have K of these models you know you have K*N sticks and K*M balls. It doesn't matter how they are arranged or even if they are connected up or what.
But you assume a certain "repetition of structure" then you are forced into certain mathematical relationships.
E.g., if you have 2 balls who can only have 2 connected sticks to them then you can't have 435 sticks. You can only have 0, 1, or 2.
So the key idea is that when you do these large scale reactions(because that is all that can be done since you can't work at a single atomic level) you can, with a few logical assumptions, work things out so it is as if you can work at the single level because it is just a "scaling problem".
When you work in moles it is just working with the # of units. If you work in mass or weight you are essentially comparing apples to oranges. It literally takes 2 moles of hydrogen and 1 mole of oxygen to create 1 mole of H2O. It's also true of any scaling of that. If we work with 1 gram of hydrogen and 1 gram of oxygen then we have problems. The math no longer is simple. I have no idea how many grams of H2O will be produced by that. We will have something left over.
So moles scales all the units properly so we can use them in chemistry in the way that they actually work(which is "pairing off" and little to do with their actual structure).
E.g., we can just define 1 mole of anything to be N of those things. As long as how we combine those things only depends on quantity then it all will work out(we then just need to figure out how to convert between that representation and other representations used(mass) which are better for other purposes).
E.g., if we have 1 mole of TV's and 1 mole of houses then that gives us 1 mole of houses with TV's. If we were talking about masses then it would be a much more complex problem(but not too difficult if all the TV's and houses weighed the same).
So the language of moles abstracts out the issues to pure quantity which along with other rules of how exactly different things can combine(the "laws of chemistry") gives us simple ways to work with chemical equations.
Basically it factors out the "combinatorics" side of the problem into a nice useful idea. It's nothing special but it is convenient.
Loved the insights!
You gave me much more than what i had asked!
PS:" If we work with 1 gram of hydrogen and 1 gram of oxygen then we have problems. The math no longer is simple. I have no idea how many grams of H2O will be produced by that. We will have something left over."
I think 0.5 moles of oxygen will be left unreacted.
@@assassin4737 No, because you have to convert those grams to moles.
Reactions are combinatorical. That is, atoms and molecules react in terms of quantities and nothing else. It's "Number theory".
That is, you can't attach half a hydrogen to an oxygen.
So you have to work in numbers of atoms rather than their masses.
So you need to know how many atoms of hydrogen exist in 1g of it. Since oxygen is essentially 16 times larger(it contains 8 protons but also around 8 neutrons) then 1gram of oxygen will be about 1/16th the size.
e.g., if you put 1g of hydrogen on the scale and 1g of oxygen on it and then counted the atoms you will have about 16 times fewer.
So, in fact, for every 16 hydrogen we have 1 oxygen. Now we need 2 hydrogen and one oxygen to form water. But we have 16 hydrogens for one oxygen(we only need 2).
What this means is that we will use up all our 1 gram of oxygen very quickly and have a lot of hydrogen left over. That is, we will have 14 left over.
This means, in proportion, 14/16 = 7/8 of the hydrogen will not be used. Or 7/8 of 1g will not be used. That is, we will have 7/8g of hydrogen left over.
So, in fact, we will have all the oxygen reacted(because all it needs is 2 hydrogen per oxygen but we have 16 per oxygen).
That is, 1g of hydrogen has 16 times the number of hydrogen. So if there are N oxygen atoms in the 1g of oxygen we have 16*N hydrogen atoms.
If we just look, as I have been doing, at one specific reaction. That is, we pretend N = 1, then we have 16 hydrogen and 1 oxygen. After the reaction we have 14 hydrogen and one H2O. So we have 14 hydrogen left over that can't react because there is no more oxygen left to react.
So, if you wanted to have a complete reaction you would need 1/16th of a gram of hydrogen and 1g of oxygen. Or 16g of hydrogen and 1g of oxygen.
The entire point of the mole is to get away from having to deal with the mass of things because then we have to know the mass relationships(which is actually more complex due to isotopes).
A mole "normalizes" things so we only are talking about numbers of atoms. Then it is easy. We know we just need 2 H and 1 O. We don't have to do any conversion.
Think about it like this: Suppose we have a "mole" weighing scale. It can weigh out moles.
We put some hydrogen on it and it says: You have 2 moles of hydrogen. Great!. We put some oxygen on it(after removing the hydrogen of course) and it says: You've got 1 mole of oxygen. Even better. Now if we stick those two amounts together we will have 1 mole of H2O. It's 1 mole because we are talking about a unit of H2O.
But 2 + 1 != 1. If we use add 1 gram of hydrogen, 1 gram of oxygen, we get 2 grams of hydrogen and oxygen and water. More specifically, we get 7/8 H + 0*O + 9/8*H2O. Here 7/8 + 0 + 9/8 = 16/8 = 2g. We started with 2 grams of stuff and ended up with 2 grams of stuff(but different types of stuff)
Basically if we are going to use mass in our reaction calculations we have to know the individual atomic mass relationships. If we use moles we don't have to know any of that. Chemical reactions essentially do not care about mass and they only care about number.
Why do I get more Ammonia then the starting amount of Nitrogen in the Haber Process? I'm not understanding that at all
i like ur little jokes, cute so nice and english.😜
Is that 23L or 22.4L
Since it’s just a number to scale by why not make it a simpler number?
★★★★★ You are a stellar educator. If you only had a sense of humour…
Does this explain the two moles of water? 2H2 + 2O2 = 2H20
There isn't even a question there, so what's there to explain lol
Volumes at standard pressure and temperature
When chemists mix chemicals, the molecules they're trying to make hava a certain number of each kind of atom. So you need to mix two molecules of this with one molecule of that, and so on. So you want to know a weight of each kind of chemical that's proportional to the number of molecules in it. Surely that's really simple.
I had a question - Why do we even need the concept of a mole? We can just make a chart of number of atoms per gram of every element and use that as an index? What is benefit of EVEN needing the mole or having the avogadros number?
I'd say it's why Ohm Law, V=IR, isn't Seimen's Law V = I/G. (G is conductance). Using atoms per gram involves inverse mass per atom and no one want's that.
Also: N_A sets the scale from microscopic to macroscopic, which is nice. Just like "c" sets the speed scale for Galileo vs Einstein, hbar sets the action scale for classical vs quantum, G (/c^4) sets the scale for Newton vs Einstein, and finally k_B sets the scale at which thermodynamics works (e.g. exact knowledge of phase space vs macroscopic averages).
@@DrDeuteron Hmm, makes sense. Its not so much science, but more about convenience then. I guess THAT should be highlighted when it is taught in school, so we know why AN is a benchmark. I guess it is like light year, it gives an idea of not just distance but time as well and convenient for extremely large distances.
Should I wash the 752 grains of rice separately before I cook them individually in very tiny pots? 😅
No, you can rinse them together.
And then separate them into tiny pots with tweezers.
@@ThreeTwentysix
😃
Depends on how many molecules of water you are going to use to cook them in, I always eyeball about 602214000000000000000 molecules per grain.
which is 18g of H20 per grain or 18 ml per grain which the chemist-chef would say is a bit much as the dish of rice would be soggy or does each grain of rice contain 6.02214x10exp 23 molecules of stuff then we have a 1:1 ratio. @@fukpoeslaw3613
I got headache when you say 2 units of water and add "vapor" in writing. Water vapor, at temperature 0⁰C isn't something I can grasp easily, ig makes me think ice-water, Arctis, how can I avoid that vapor will condense? And such.
🤔➕️🔜↪️⏩️⚡️😇
"they might just be numbers to you!" monty python humour vibes
At t=8:37 he said 23 l and suggested a small fish tank. There is something fishy here...
People want to convert moles to liters but they are incorrect. Moles come in LITTERS. 🤣
I can easily imagine a million of something. A cube of 100 things on each edge.
But i also regularly use the term "brazillian". 😂
The joke is genius😂
They use moles to spy on chemical reactions. That’s all I learned in my college Chem 101 class.
A mole is needed to convert the weights of atoms or molecules in amus to their conglomerate weight in grams.... End of explanation.
If it were not for the Chemistry of Gasses, we might not have 10% of the Understanding of reality that we have today.
I don't mean to alarm you, but i think there might be mole in your lab.
Mole🐀🐀🐁🐁??
...bit of an aside.
Medics love their latin too.
So a skin mole is a pile of keratinocytes?🤔
Lmao had me dying. You fiend. The moles have poor eyesight, it'll take them forever
NO I CARNT IMAGINE A MILLION MOLECULES BETWEEN YOR FINGERS BUT IMAGINING INFINITY IS EASY,
This isnt for beginners! - never heard of Zealites. I endured a "chemistry education - 1959 _- 1964, & passd O level GCE . . Why break down Butane - a useful industrial gas, into Methane - a nuisance greenhouse gas? You lost me when talkin about Sulphites!
why not use them, since biologists use rats and physicists use cats?
Is it because they are cute and furry and catch worms?
They work cheap
The concept was formulated by Dr. Mohl or mol,...not "mole"!!!
And one mol-ecule is a fraction of a mol, right?
Like a millimeter is a fraction of a meter ...
@@notconnected3815 Okay, so maybe that is the origin of the name.