foreign for all of you okay I will take one more lecture don't worry okay so are you all excited can you all let me know in the lectures this chapter will become assault for everyone even though you are okay great so welcome welcome everyone I am so happy to have you all here number chemistry the new masu batch so let's get started so yeah in the channel in the channels because it is very nice to study in our mother tongue feel how many of you have felt that in the channel English news chemistry science we will learn and we will outshine everybody okay so let us get started so are you all ready for the marathon you know in the session at least two hours okay so I can only teach for two hours maximum so I can take for two hours maybe we will continue up to 9 30. shall we very good so let's get started okay everybody please let me know see I want you guys to talk about it is mass of an atom it is just mass of an atom if atoms can be of different elements is yes do you all agree very good you guys are amazing so atomic mass mass of one atom is called as atomic mass Masa everybody happy with this great very very good basics of this chapter is okay you need to be able to find out atomic mass molecular mass of various compounds because all that will be used in mole concept that is stoichiometry okay it is just mass of single atom of an element okay everybody clear so if I will give you atomic mass of important elements atoms are very important so on the list okay and now what I am giving you is bare minimum at least cbse level in the neat level classroom maybe for J means J Advance you need to study something more than what I give but for cbse and neat level okay great one atom of oxygen otherwise the atomic mass of oxygen can you guys let me know very good you guys are awesome ours is an atomic mass is 16 it's not 32 okay 32 on the molecular mass O2 got it so oxygen atomic mass is 16 chlorine atomic masses 35.5 okay it is 35.5 very good my dear boys and girls you are all absolutely amazing keep it up keep it up so this is atomic mass unit atomic mass unit okay and this is called unified math okay foreign rules to follow IUPAC rules to follow for naming carbon and its compounds yes they have they have let us know that we will follow or adapt you instead of AMU okay we use only you is I hope you are all clear I hope all of you are happy with this is 1 12 the mass of one carbon 12 atom okay have you guys heard about it yes I hope all of you are clear yeah voice finally no man is can I continue teaching yes but everybody is saying that it's clear it's fine so we will go ahead okay foreign yes you are all measuring in kg the reference it is 1 12 the mass of carbon 12 atom it is 1 12 the mass of carbon 12 atoms very simple great I hope this is clear to everybody okay so for the purpose of determining atomic mass of various elements the mass of carbon 12 is taken to be the standard okay so carbon 12 atom mode to understand the atomic mass of all the other elements all the other molecules compounds that we will study in the coming days okay fantastic atomic mass atomic mass now it is nothing but how many times an atom is heavier than 1 Amu how many times an atom is heavier than 1 12 of carbon-12 atom our law okay so carbon 12 atom odor 1 12th weighted atomic mass I hope all of you are clear okay cbac ncert these are all just definitions but we'll go forward okay great it is just how many times as compared to 1 AMU okay so one am United one a.m 112 the mass of C12 atom so C to a lot of reference are you guys happy with this yes yes please wait for it okay so in the in the chemical reactions Stoichiometry balancing and more Concepts I have listed it out here please make a note of it one new 12u nitrogen 14U are you all able to get this so either screenshots it is just another symbol for Amu physical chemistry it will be a piece of cake foreign it is 1 12 the mass of C12 atom very good did you all like it Masa great so that is how you learn it so that is how you understand it okay voice is but I still see some messages that voice is not clear please let me know if there is any problem okay why is this clear very good very good okay I'll teach okay please okay foreign I hope all of you are clear are you all happy with this great great great it is defined I hope you guys enjoyed it now we'll go forward okay so in the valuesla remember Panna in the Allah everything what I have given here is important for solving okay very good so if do I remember all these values yes but don't worry you will slowly get the hang of it you will get the hang of it as we install 50 problem 100 problems 200 problems you will get better at it more Concepts you'll become better you will become the best but you need to keep solving will you all do that every day solve 10 questions on mole concept you will get better okay so yeah now let's move forward so one AMU alone how many of you know sir one AMU okay sir number everything is foreign what is 1 AMU in grams very good Cobra brilliant so one AMU in grams every size mass of one carbon 12 atom number scientists experiments okay I will show that to you in a short while okay we can understand one AMU how much in grams okay it is molarity and molality I will teach you both don't worry okay it is 1.66 into 10 to the power yellow minus 24 grams are you all clear with that atomic mass unit foreign foreign foreign did you all enjoy it amazing right how many of you are happy guys you all understood what is the weight of one atom of oxygen in grams so like that you can calculate the weight of any atom in grams same manner in the similar way okay foreign yes very very very good sir sir one AMU equal to 1.66 into 10 to the power minus 24 grams is another what are isotopes can anybody tell me what are isotopes Isotopes are same atomic number and different mass number character exactly so Isotopes isotopes you want to be a doctor you want to get good results in board exams Isotopes isobars ISO tones in the moon way you should know okay C12 is an isotope of carbon okay they found out the mass of c2l atom through Mass spectrometer that's an experiment they conduct and they were able to find out the mass of C12 atom is approximately 1.92 into 10 to the power minus 23 kg so either experiment volume approximately 1.92 so if either they wanted to find AMU so AMU is what 1 12 of this so I have to divide this by 12. so 1 by 12 of C12 atom is 1 by 12 of this which will give you this value Masa so you understood the derivation okay you understood the derivation of 1 AMU 1.99 yes yes guys I am just giving you a rough idea 1.99 1.92 similar okay I hope you all understood it derivation of 1 Amu are you all happy now guys I have given you the concept behind what is one emu Israel don't ever forget it because these are beautiful things which help you really appreciate chemistry and understand it in the best manner possible okay very good Basics so first one atomic mass of young nitrogen is 14. foreign [Music] what is the mass of one nitrogen atom in grams so mass of one nitrogen atom in grams is 14 Amu energy so AMU grams 1.66 into 10 to the power minus 24 grams so the answer this is the mass of nitrogen atom in grams I hope all of you are clear because you guys are absolutely amazing okay you guys are absolutely amazing are you all clear everybody brilliant very very good Superba is if you brush up if you go through this everybody will follow okay now let's move forward relative atomic mass now how many times how many times atom is heavier as compared to 1 12 the mass of carbon atom okay so what is relative atomic mass of your atom whatever you are finding okay divided by 1 12 mass of C to L atom patina C12 1 12 weight order how many times it is heavier r a m it is relative atomic mass okay my voice is not cleared is it better now yes okay now it's clear great great I think now it will be all right so passing law relative atomic mass now 1 12 the mass of C12 other cartoon foreign yes so shall I move forward I don't know why the voice is low okay hello hello it's perfect okay okay I think I'll have to touch it and only talk okay it doesn't matter relative atomic meaning I hope all of you are happy with this see relative atomic mass 1 12 the mass of carbon 12 atom other number foreign did you all like it yes so relative atomic mass times heavy are you all clear so if I'm I am 70 kg and you are 35 kg my relative atomic mass is 2 because 70 divided by 35 number relative atomic mass space the numerator is mass of your atom whatever you are talking about whatever you are talking about okay divided by the denominator the reference the base is always the same it is 1 12 the mass of C to L atom these are all basics foreign let's go forward the mass of oxygen atom is 16 AMU 16 a.m 16 times 1 AMU 1 am United 1 12 the mass of C12 atom got it foreign yes till now are you clear are you all happy because we have a long way to go we have just done little bit as of now you know okay very good Sanjay very good superb great so atomic mass of nitrogen on the 14 AMU so 14 into AMU YOLO AMU 1D 1.66 into 10 to the power minus 24 grams okay so either the atomic mass of nitrogen in grams is can you all find out what is the atomic mass of chlorine everybody find it out and tell me um what is the atomic mass of chlorine 35.5 it is relative atomic mass because relative atomic mass units when you say relative atomic mass then there is no unit I am asking you atomic mass of chlorine atomic mass of chlorina 35.5 Amu let number gen Z generation 35.5 gramsler so grams 35.5 into 1.66 into 10 to the power minus 24 gramsa did you all like it happy Clarity so relative atomic mass units relative atomic mass denominator you have one Amu you are dividing by one emu so AMU AMU cancel so relative atomic mass units what is relative atomic mass of oxygen what is relative atomic mass of oxygen can you guys tell me everybody it is 16 very good don't tell 16 AMU 16 a.m relative atomic mass of oxygen is 16. now I'll ask you what is atomic mass of oxygen what is atomic mass of oxygen can you guys answer that atomic mass of oxygen is 16 U 16 grams 16 grams 16 grams okay atomic mass of oxygen atomic mass of oxygen easy hello 16 you but either way relative atomic mass of oxygen atom has been guitar 16. did you all like it are you all happy so shall I move forward I am sure now all of you would have understood it everybody happy with this so shall I proceed niranjan now first standard maths teacher I will help you don't worry okay Kanna very good sudesh don't worry sudesh if you listen to it once or twice more you will understand everything these are all Basics these are all not difficult stuff laddu stuff okay foreign so H2 irinsana what is the molecular mass so render hydrogen atom or oxygen atom so render hydrogen atom now 2 into 1u plus oxygen atom so the atomic or molecular mass of water is 18 new Supra so one molecule of water will have a weight will have a molecular mass of 18 U Supra did you like it so I hope all of you enjoyed it so this is how you find out molecular mass everybody please try to follow along with me number molecular mass of water H2O okay render atom of hydrogen and over atom of oxygen go check it out okay everybody please try to solve it subramanian very good halita rehana right super proud of you very well done you guys deserve a big round of applause for this because you guys are amazing so how do you find this out Plus the atomic mass of carbon is 12. so over carbon 12 units null hydrogen or a hydrogen on the core unit so 4 into 1u got it so 12 U plus 4u 16 U is the mass of CH4 molecular mass of CH4 foreign foreign number Prince Jewelers Kalyan Jewelers there are so many Brands out there foreign so don't tell grams grams is a very big weight when you talk about molecules it is going to be 16 you you another you the atomic mass unit which is 1.66 into 10 to the power minus 24 grams Masa so number CH4 molecule of eight did you all love it are you happy is 16 grams now it's very heavy one molecule cannot be 16 grams so don't ever say that okay let's go forward yeah in the example social science foreign let's say it's 50 grams there are 25 rupee coins when they have thousands and thousands and thousands of coins how they measure accurately is by weight so Ella 5 rupee coins attack s they will tell you how many coins are there how many of you have felt that is did you guys notice that yes it is very difficult rotten a term called mole yeah what does one doesn't mean one doesn't means dwell I am going to introduce you to one new term called mole okay so in chemistry also scientists link the mass of an element to the number of atoms present inside them so director is so what is mole mole is nothing but collection of 6.022 into 10 to the power 23 particles you can also say one mole of raghavan one mole of one mole of raghavanna it is nothing but one mole of it is nothing but 6.022 into 10 to the power 23 raghavan foreign you can use it for anything you can use it for anything it is just number of things number of particles so this is what we call as n a which is called as Avogadro's Number Avogadro's constant Syria is please listen carefully [Music] 16 grams character foreign it is the weight of one mole of oxygen okay it is the weight of one mole of oxygen sir every sir I will prove it you guys are ready every one mole of oxygen on the 16 grams are on the chair when we go to problems okay problems I will ensure that so let's start see atom of oxygen is 16 U correct up I want 6.022 into 10 to the power 23 atoms of oxygen foreign [Music] [Music] correct everybody happy it is 1.66 into 10 to the power minus 24 grams correct up 1.66 into 10 to the power minus 24 grams did you notice sir if you multiply Avogadro number with one AMU you will get one yes did you all like it sorry sir 10 to the power 23 either 10 to the power minus 24 so either end if you multiply upon now I'll get 10 to the power minus 1. and 6.022 into 1.66 will be approximately 10 so 10 into 10 power minus 1 is 1. level up so if these two are one so 1 into 16 grams will be the answer okay I hope you are able to follow these are all very very good things okay so one mole of oxygen atoms will weigh 16 grams one mole of oxygen atoms will weigh 16 grams clear so one mole one mole now 6.022 into 10 to the power 23 particles so one mole of atoms one mole of molecules okay very good so I can say that mole is a link between mass of atom and the number of atoms okay mole is a link between mass of atoms and the number of atoms one mole of oxygens one mole of oxygen atoms so other advantage of studying in moles Jason please 6.022 into 10 to the power 23 that is Avogadro's number got it so passing law either you clear up either either foreign I hope all of you are able to follow all of you are having fun yes he looks very weird hey these are all very olden day pictures man some of them are from painting they are not even photos Okay so don't bother atoms one mole of hydrogen atoms now you know hydrogen atoms got it one mole of molecules now uvulo molecules got it so one more one more 6.022 into 10 to the power 23 particles okay other atoms are molecules it can be anything that you are finding out the mass of one mole of any substance in grams is called molar mass I will try to help you out the mass of one mole of a substance in grams is called molar mass for example now in this one mole of hydrogen atoms up one mole of hydrogen atoms can anybody let me know quickly yes one mole of hydrogen atom sort of weight YOLO is it one gram or one you one you are or one grammar corrector can everybody answer everybody in the chat please go for it it is one gram this is 6.022 into 10 to the power 23 atoms of hydrogen it is one gram every one gram how did one gram come I will teach you okay see atom of hydrogen this will be the last time I'll explain one atom of hydrogen on there it is one atomic mass unit so that weight would be 6.022 into 10 to the power 23 into 1 Amu you will get one gram um do you all get it you know more concerts one gram grams is very easy it's very very easy either Advantage 14 grams foreign foreign mass in grams is equivalent to Atomic or molecular mass for example molar mass of water you know okay molar mass of water so water on the H2O so over a molecule on the 18 U one molecule of water is 18 uh one mole of water one mole of H2O that will be 18 uh that's it so when you know one molecule or one atom's weight it is very easy to convert it to one mole and that's it that's it are you all clear happy that's it over great great great examples what is one molecule of NaCl one molecule of NaCl weight patina it is n a is 23 did you all note it down now or a table on the table I would have explained very good chlorine 35.5 so it'll be 58.5 U it will be 58.5 uh number one molecule I want one mole one mole of naclow one more will be one molecule on the 58.5 grams left that's it now you guys have Got Confidence so shall we move forward it is molecular molar mass not molecular mass it's molar mass okay mole of nitrogen atoms very good super I am happy that you guys have understood all this is now only we are starting mole concept it is just story it is just chapter is beginning so Shall We Begin everybody a very good soon first what I'm gonna teach you is how to find number of moles number of moles important so please this is very very crucial to master physical chemistry physical chemistry in the concepts you have to be very very thorough okay so first how to calculate number of moles OKAY model formula please formula molds number of moles is given mass by molar mass okay number of moles so I'll use this formula number of moles is equal to given mass given mass divided by divided by molar mass how do we find molar mass o on the 16 H1 the one so it will be 40. so or a molecule 40 U one molecule of NaOH is 40u but number molar mass means one mole of NaOH one mole of NaOH is 40 gram got it so 120 by 40 will be 3 so you guys are absolutely correct yes very good I am very very proud of you all let's go forward you know my slow workouts everybody clear thank you so much boys and girls units in a number of moles number of moles when you say number of things you don't say units right I'll say only okay I will not say anything else right so you just say number number very good week I want to see how many of you will get the right answer okay very good SRI Shalini fantastic molar mass given mass is in grams molar mass is also in grams so grams of grams to cancel iron okay so every solventing a number of moles formula is given mass given mass is 900 grams divided by molar mass of C6 h12o6 Ilia so C6H12O6 what will be the weight 6 into 12 in our over Carbon on the 12. foreign foreign [Music] did you like it was it good shall we move forward yeshwan thank you so much wanna come nice to see you here so shall we move forward the second formula is number of particles by Avogadro's number thank you so much that is so kind of you so second formula number of particles by Avogadro number of particles to find out number of moles did you all note it down see answering yeah in your board exam that is more important did you note it down I have given you two so please note this down now let's try to solve it so number of moles hello given number of particles so yellow particles 30 into 10 to the power 23 divided by what is n a n a is Avogadro number of particles so what is Avogadro number it is 6 into 10 to the power 23. okay so answer is five okay happy okay okay so I hope all of you are clearly everybody happy with this yes now let's go to the next one people everybody listen carefully the next question is again from this one please do it foreign great so let's move forward are you guys ready shall we go forward this is for gases this is for gases this is only for special specimen number gases so this formula is only for gases that too at STP is standard temperature and pressure okay it is not any pressure any temperature it is at One ATM pressure and 273 Kelvin that is STP so gases foreign it is atmospheric pressure it is atmospheric pressure One ATM means one atmospheric pressure okay so now in the formula number of moles is equal to given volume of gas divided by 22.4 liters okay given volume of gas in liters by 22.4 liters milliliters given volume in ml divided by twenty two thousand four hundred okay number of moles is given volume in the formula 44.8 by 22.4 sir they gave STP they gave standard temperature pressure are you all happy everybody clear with this so shall I move forward now let's go forward the various formulas that I gave you okay the various formulas that I gave you okay so if number of particles number of particles you can multiply with n a the number of particles you multiply n a with mole is they are coming from the three formulas that I gave you so nice see number of moles is number of particles divided by Avogadro number so number of particles divided by Avogadro number will give you moles mind map mind maps in the diagram Supra so passing law number of particles divided by Avogadro number will give you mole okay molds into moles into avocado number will give you a number of particles moles into avocado number will give you number of particles Mass are did you like it so first one so shall I move forward are you all happy with this passing law very good number of moles is equal to given volume of gas at STP divided by 22.4 so if you divide the given volume by 22.4 liters you will get moles given volume divided by 22.4 will give you moles moles into 22.4 will give you given volume of gas at STP so moles into 22.4 will give you the volume of gas at STP are you all happy please note down this diagram then we will move forward [Music] if you are enjoying it so far yes did you all enjoy it Vara level okay thank you so much is saying that this is called as y map it is called as y map is only easy to remember meaning are you all clear great moles is equal to given weight given weight or mass by molar mass okay given weight or given mass by molar mass so moles is nothing but given mass divided by molar mass will give you moles given mass divided by molar mass or atomic mass will give you number of moles so mass divided by molecular mass mass divided by atomic weight mass divided by molecular weight will give you moles weight in grams will give you given Mass into molecular weight or molar weight will give you Mass subra molecular mass in grams other molar mass it's a large number of particles it is 6.022 into 10 to the power 23 particles come on guys let's solve questions everybody take out your pen take out your notebook let's solve it calculate the number of atoms molecules present in the following at STP calculate the number of atoms or molecules present in the following at STP conditions everybody I will check how many of you are doing it right in over a half an hour till 9 30 I will teach you how much ever I can you know in the chapter is you will be very confident in physical chemistry so number of moles number of moles is equal to another STP conditions standard temperature pressure and we are talking about gas helium gas methane gas CH4 is methane gas so number of moles is volume in liters by 22.4 liters so number of moles is 1 by 100 0.01 [Music] he asked number of atoms what is it formula number of particles number of atoms divided by Avogadro number is number of moles number doctors number Engineers you need to understand this so number of atoms by n a is number of moles number of moles 0.01 so number of atoms is 0.01 into Avogadro number so the answer is 6.022 into 10 to the power 21. either very good did you all love it Akshay ganga 0.1 0.01 rather very good check it check it it is 6.022 into 10 to the power 21. very good now in the formula is I will not go forward let's understand it properly and only then we'll move forward okay so please listen carefully number of moles is 0.01 you all agree everybody is happy with that there is no doubt about it now let's move forward I also gave you one more formula moles on there it is number of particles number of particles divided by Avogadro number correct is particles atoms particles atoms yeah and I am talking about helium atom so particles for this question is atoms of helium character so if we want to find number of atoms so I want to find numerator numerator do I know this no sir 0.01 number of moles is 0.01 and this is Avogadro number Avogadro number energy 0.01 into Avogadro number that is your answer are you clear happier so shall we move forward very good brilliant guys amazing that is the way you all do it I hope you enjoyed it so shall I proceed next one very good super next one kandipa yeah I know so number of moles is volume in liters by 22.4 other formula when you have a gas at STP the formula is volume in liters by 22.4 so 44.8 liters by 22.4 liters so answer is 2. character very good now second formula is number of particles moles can witnessed number of particles by Avogadro number correct either second formula foreign is it atoms or molecules it is molecules it is molecules of CH4 number of molecules of th4 so foreign foreign this is number of molecules but if I asked you a number of atoms then it will be into Phi either number of molecules into Phi Pana number of atoms one carbon four hydrogen Massa do you like it so that is why atoms Theta into Phi panu you know how many atoms are there in that molecule with that you have to multiply okay are you all clear so this is something very important okay Subaru super so now try to solve this come on guys very good question okay everybody please try to solve this quick quick quick [Music] you will become better you will be unstoppable so start it what is the answer so first is first we need to find out moles step by step by step so first to find atoms let's find number of moles so number of moles foreign foreign [Music] we want atoms we want atoms so half moles we will use that formula what is the formula n is equal to number of atoms mg single atom so number of atoms divided by Avogadro number so either one the half so half is equal to number of mg atoms number of mg atoms divided by Avogadro number 6.02 into 10 to the power 23 so number of mg atoms number of mg atoms don't give up come on guys I want everybody to participate number of mg atoms it'll be 3 into it will be 3.01 into 10 to the power 23. atoms very good Json super thank you so much Santosh Harish very good job guys brilliant you guys are amazing mole a either calculate it'll be yellow moles one by four mole either calculate it'll be one mole either you know none of these so now yeah either one mole is one by four mole with one mole upon none of these are foreign see number of moles is given mass by molecular mass that is molar mass I am happy you guys learned it so this is number of moles so either one there it is equal to number of particles so second question particles in a particle atoms are molecular second question molecule sir number of N2 molecule divided by Avogadro's number okay so avocado number across multiply I will get like this Ilya N2 molecules but if I want atoms I have render atom so the answer will be 2 into 1 by 4 into n a which is 3.01 into 10 to the power 23 foreign yes very good question I hope you all enjoyed it this is a very good question you go through it is very good so now let's move forward foreign foreign yes we will continue it in the next lecture I want you guys to solve it and come Okay so okay great so we will continue we'll continue in the next class what is important so please we will continue it tomorrow or day after I will let you know but please be regular okay okay thank you so much in the lecture friends smash the like button and subscribe to the channel if you haven't I will see you in the next one until then take care all the very best love you bye