Lecture 5| LT - 2026 - 2027 _ ONLINE GOAL BATCH - CHEMISTRY - T1 [ PANT SIR ]

[00:00:00]Good morning by good morning. Good morning. Good morning. Once check audio video is clear.

[00:00:09]Once check if [clears throat] audio and video are clear by audio video clear.

[00:00:24]Good morning guy. Good morning. Good morning. How was the paper?

[00:00:29]How was the paper?

[00:00:37]Good morning. Good morning. Good morning. Paper forgot paper was there on Sunday.

[00:00:43]How was it?

[00:00:53]Good.

[00:00:56]Just good. Any doubt in the paper? Because no doubt came.

[00:01:06]Maybe [clears throat] you were busy checking your OMR sheet.

[00:01:15]Yes. Key change for 144. I think that question is 10 - 21 - 24.

[00:01:21]Zto in that key change is there 10^ minus 21 is there Sur question was simple but common sense is not so simple now whosoever will take more time for example Sur delivers something in 1 minute Romesh is delivering in 5 minutes to Romesh is taking more time he's slow who takes more time Slow people will take more time or fast people will take more time.

[00:01:55]But sometimes common sense is very uncommon by there the blunder can happen.

[00:02:04]So that only one question was there which is new model as our planning you might have understood also. We have taken one session to explain the planning also. Did you see that session?

[00:02:16]How are we going to upgrade the level slowly slowly? So in the beginning one two new question will come.

[00:02:23]So let's say one in track one one in track to like total two questions in the beginning which are new. Then slowly slowly we are going to increase that number to 3 4 5 6 then after 2 3 months you will get some paper where all the questions can be new totally fresh and [clears throat] there this fundamentals only are checked. Yeah such a simple fundamental that you every day you can order blanket and swing instart nowadays wherever you might be. If not that at least Amazon, Flipkart and you see the delivery time and you always order from the place where the delivery time is less whosoever deliver in for example Amazon Prime say we will deliver in 1 day. So that is fast or slower than flip card which is doing in 3 days common sense there even non-science people know it clear better that a sir you can ask how can I know where a sir homework is posted I think he would have sent in the app probably that's why you might not have got it so I'll ask him he can post in the description box then you can get by so understand like this some more questions will be there to not in the app doesn't matter I'm not a sir so let's talk about the point clear I so so make sure that you make your brain open for new questions as well because if you're answering it wrong then in the study hour or in the time after the exam you have to make the error book you have to write the explanation there and then you have to write the real life example because common sense you can Get common means something around us only going on that only we are asking in the exam in a scientific manner and there your brain becomes suddenly zero your brain does not work brain fade situation comes if that has to be addressed after the exam that has to be addressed by you only because if I tell you then you will mug up now I mugged up time is less the speed will be more and then some people will start writing formula speed equal to distance upon time to speed and time are inverse proportional. You don't have to learn a new thing to answer a fundamental question. That's why we call it fundamental.

[00:04:39]You have to just understand why whatever you knew you were still not able to deliver in the exam. And that can only be understood by writing the error book and understanding the pattern of which type of questions you are doing wrong.

[00:04:53]And then automatically once you know the problem you will you'll be able to find the solution. The biggest problem is diagnosis.

[00:04:59]We are not able to diagnose our problem and we are taking the medication for random things to diagnose the problem by seeing the pattern which you are doing wrong in track one track two physics chemistry bio got my point by so even though the paper was from the fundamental topic which is generally not tough for you outside the paper will be very tough because you will not know the meaning of zeppto at ea exa nothing for you it will not be that much stuff. That means we teach good, we give good and then the paper appears easy to you. But in that paper also if you're not maintaining the error book when you have hardly 5 10 15 errors then when the paper will come from deeper science where you will do more mistakes where the subject will become tougher then you will not have the habit of maintaining the error book and from there your downfall will start.

[00:05:52]So don't start your downfall by the downfall will not come you will start it if by not doing the things on a regular basis ready shall we start not the downfall but the flight some basic concepts of chemistry Ready? Y ready?

[00:06:22]Are you ready? Cha. Some basic concepts of chemistry.

[00:06:27][clears throat] But yeah. So toa tell me CO2 O2.

[00:06:40]My question is out of these two which one is a molecule and which one is a compound?

[00:06:48]Out of CO2 and O2 which one is a molecule and which one is a compound first which one is a molecule which one is a compound basic concepts of chemistry onwards from elementary things I will start from class sixth onwards I will start. So don't be unnecessarily overconfident because you know a few things getting by but yeah the CO2 compound O2 molecule O2 molecule CO2 compound okay more or less I think every one in the beginning started answering answer is almost correct only take CO2 compound CO2 compound the interesting thing is People are saying O2 is a molecule. Most of the people except our last year student except them. Except them one girl is there last year. Except her remaining all are saying that CO2 is a compound and O2 is a molecule. And your answer is bil bakas.

[00:07:57]So are we ready to understand sixth class science junior interview? Later on we will start. Shall we start this by shall we understand the meaning of element, compound, atom, molecule, atom to generally people know and molecule properly with proper definitions and examples so that no one else can confuse us with me you have that rep okay sir will ask something I can answer wrong because he is our teacher but outside no one should be able to humiliate you because people will now make fun by asking this this much also you don't No this chance we should not give to anyone by outside. Shall we start? Ready?

[00:08:42]Ready. Now understand we have to classify in on which basis the classification has to occur. Check properly. Why? I am doing two classification. The opposite of atom is molecule. The counterpart of atom is molecule.

[00:09:02]The counterpart of element is compound.

[00:09:09]Understand why molecule and compound are not opposite of each other. Molecule and compound are not opposite of each other.

[00:09:18]If you really want to call something as opposite for your understanding if not compound then what? Then element will be better to say not molecule. Now atom I think everyone know like hydrogen atom, helium atom, nitrogen atom, oxygen atom, florine atom, carbon atom.

[00:09:38]These atoms we know molecule definition is understand the proper definition. The definition is combination of atoms to be precise it is a combination of atom in a fixed ratio. But I'm not talking about fixed ratio right now because that is not your problem. Your problem was molecule compound stupidity.

[00:10:01]Combination of atom. Combination of same type of atom or different type of atom.

[00:10:06]Sir, you did not say same type different type. You just said combination of atom.

[00:10:11]That means combination of every type of atom. I will call as molecule. Whether you are combining O with O, O with O or you are combining different types of atom or you are combining different types of atom or you are combining different types of atom like rather than CA3 I will take the example of N2O these are called CA3 also we can take in simpler manner getting by CA3 also we can say in the simple manner but I don't want to use that example you will understand very soon Why? Perfect knowledge should be there. Why? No one should be able to confuse us ever. That's why combination of same type of atom, combination of different types of atom, everything is a molecule to say the meaning of molecule.

[00:10:59]Clear?

[00:11:01]So by that definition CO2 combination of atom doesn't matter same type or different type combination of atom will be a molecule combination of atom will be a molecule by that means CO2 and O2 both are molecules both are combination of atoms Say by clear or not clear very simple elementary thing combination of atoms or molecule doesn't matter same type of atom or different type of atom then element element means same type of atom or atoms to when you have one type of atom Just one type of atom it is called element. And when you have more than one type of atom then I will call it compound.

[00:12:16]Now tell me more than one type of atom means will O2 be a compound? I think this much everyone know because in previous example also you did not give the wrong answer in O2. You understand O2 is not a compound. Compound is different types of atom. So like CO2 will be called a compound. Like N O N2O these are called a compound. CO clear. These kind of people are called as a compound.

[00:12:48]Different types of atom more than one type of atom. Different types of atoms are there. We call it compound. Clear or not clear. So by that logic you were correctly saying that CO2 is a compound but O2 is not a compound. 100% correct.

[00:13:05]Your only fundamental which was wrong was you were thinking compound and molecule are opposite of each other. You were not understanding that molecule can be a compound and compound is a molecule. I will talk about those statement later but understood the meaning of compound.

[00:13:21]Element same type of atoms are element.

[00:13:24]like O N O2 N2 can I call all of them element or some problem is there by this definition of element if this definition of element is correct same type of atom or atoms then all four of them are element or not then all of them are element or only O and N are element or only O2 and N2 are element according to you what will be correct According to this definition, what examples are correct? All four correct or only these two or only these two.

[00:14:08]Now O and N correct by O and N.

[00:14:16]Why is because see why this doubt can come if you think harder. If you even forget the definition you will realize sir periodicity of the elements we are reading periodic table means periodicity of elements and there the element you are calling element are atoms say by once think about this you will realize why people are giving O and N as the answer maybe they are correct don't assume that they are wrong don't be having one-sided knowledge Think of all the possibilities and then figure out the correct answer. Are you realizing or not that periodicity in the property of elements classification of elements the element which we call as element are atoms there we don't talk about the O2 radius correct.

[00:15:14]So that is one way in which we can think but that is incomplete.

[00:15:20]Sir, how do you know it is incomplete or how can we know it is incomplete?

[00:15:23]Because you have not read the definition of element.

[00:15:27]You assumed the definition of element.

[00:15:30]If you are thinking this that means you are believing that element are atoms. You have not read somewhere the meaning of element. So shall we read the meaning of element?

[00:15:41]Shall we read the meaning of element?

[00:15:45]so that we don't have any confusion in future. Any kind of doubts which you can have should be rectified. Now let us see the definition of element s the NCRT and you will realize that all four of them which I have written they all were element according to the definition and that is correct also. See now read this. Pure substances can be further classified into elements and compounds.

[00:16:14]Particles of an element consist of only one type of atoms.

[00:16:20]These particle may exist as atoms.

[00:16:25]They can exist as atom or molecule. The O2 and N2 are molecules.

[00:16:32]But they can also exist as atom. That means O and N is also element which you are accepting anyway because in periodic table you call those atoms only as element. I am saying molecule also correct as per the definition. So now tell me in my definition you see so that no confusion is there. I have written same type of atom or atoms. So that with atom also you should have no confusion with atoms also it's a very dumb way of writing we should actually say same type of atoms grammatically but grammar grammar doesn't matter if you're not understanding the language is to convey the meaning if the meaning is conveyed by wrong grammar I will use wrong grammar so that's why I'm saying same type of atom or atoms to say is the element compound molecule atom basic idea Clear basic idea clear by so now tell me now tell me H O2 is now O2 is atom. No sir, O2 is a molecule. O2 is element or compound. O2 is element or compound. So compound means more than one type of atom. It has same type of atom O. So it is a molecule and a compound and a element. So can I call it O2 is elemental molecule?

[00:18:23]It is element and molecule. It's a molecule of an element.

[00:18:29]But CO2 is it is also a molecule.

[00:18:34]Combination of atom combination of atom same type different type doesn't matter.

[00:18:40]Combination of atom is molecule to CO2 is compound molecule.

[00:18:51]Do you agree now?

[00:18:53]Are you clear with this? That O2 is element and element and molecule. CO2 is compound and molecule. The CO2 is a compound molecule. O2 is an elemental molecule.

[00:19:14]It is just like saying key are you a boy or a future doctor? So sir I can be boy also doctor also I can be girl also doctor also I can be boy also engineer also I can be doctor also engineer also these are two different classification now doctor and engineer is a professional classification boy and girl are gender classification you can be boy and doctor boy and engineer girl and doctor and engineer combinations are possible in the same way you can be molecule as As well as element you can be molecule as well as compound.

[00:19:54]Making sense.

[00:19:57]Making sense.

[00:20:03]Once it will start making sense then my job is to confuse you so that outside no one can confuse you.

[00:20:10]Ready? Fundamental clear.

[00:20:14]Fundamental clear.

[00:20:17]Now tell me am I trying to say this can be this also this can be this also. This cannot be this. This cannot be this.

[00:20:26]This cannot be that. Are you getting?

[00:20:28]Atom boy cannot be girl. Girl cannot be boy. Doctor is not an engineer. Engineer is not not a doctor.

[00:20:36]Clear? Atom is not a molecule. Molecule is not an atom. But molecule can be element. Molecule can be compound.

[00:20:43]Compound cannot be element. Element cannot be compound. Are you getting the point? These are complimentary of each other. They are against each other we can say. But these and this combination, this and that combination is possible.

[00:20:58]So by that logic give me true or false state true or false compounds can be elements.

[00:21:20]Number two, element can be atoms, element can be molecule, compound can be atom, compound can be molecule.

[00:21:48]Say by State true or false?

[00:21:53]Compound can be elements sir. Element means same type of atom. Compound means more than one type of atom. Their definitions are opposite of each other.

[00:22:04]So the first one is 100% going to be false.

[00:22:09]Why compound and element are exactly opposite of each other? Same type of atom.

[00:22:18]Same type of atom getting by element different type of atom compounds to say in the question number one anyone have any problem by question number one if problem there give a yes problem not there give a no then only I will go ahead no problem.

[00:22:49]But yeah, element can be atom. Yes, true.

[00:22:55]What we understand is that element can be atom also and element can be molecule also.

[00:23:08]This we read in the NCERT also. We read exactly this line of NCERTT that element can be element consist of only one type of atoms. These particle may exist as atom or molecules.

[00:23:22]So that means element can be atom also.

[00:23:25]Element can be molecule also. So both statements are true.

[00:23:30]Element can be a molecule. Element can be an atom. The element can be atom also molecule also. Now compound can be an atom.

[00:23:40]Compound can be an atom.

[00:23:44]Compound can be an atom to sir. Compound means different types of atom. Different types means minimum two atom must be there. Different type same type of one atom possible. O is only one type of atom. O is only one type of atom element. But different type of atom means at least two different atoms must be there. And when there are at least two different atom, how can I call him atom? It becomes a molecule. So this will be false. In fourth one, anyone have any problem right now? Tell time is there. Compound is a combination of different types of atoms. So I can't call it atom. Compound will always be a molecule.

[00:24:32]Compound will always be a molecule.

[00:24:42]Done by no problem. Great. Compound can be a molecule. I will change it slightly.

[00:24:50]Compound will be a molecule. And this statement also I can say true.

[00:25:00]I'm not just saying can be can be obviously true. I'm saying it will be 100% it will be a molecule compound.

[00:25:08]Why? Because compound means more than one type of atom. So when more than one type of atom combine it is combination of atom it will always be a molecule.

[00:25:18]Clear?

[00:25:20]That means if I write here compound to compound can be a molecule molecule can be a compound.

[00:25:28]Compound can be a molecule. Molecule can be a compound.

[00:25:37]H but compound cannot be atom and atom cannot be compound. Are you getting? Atom can be element, atom cannot be compound. Molecule can be element also compound also. So molecules are of two types.

[00:25:55]Molecules are of two types. Elemental molecule compound molecule. Same type of atom combine element. Different type of atom combined compound. Element are also of two types. Element also are of two types. Atomic element, molecular element. Example O, example O2.

[00:26:18]Molecule can also be of two type.

[00:26:20]Element and compound. Element can be of two type. Atom and molecule.

[00:26:25]Atom is not of two type. Atom is always element. There is no other option.

[00:26:30]Compound cannot be atom. Compound will always be molecule to say by the history, geography, civics and hence chemistry of this topic is clear to you or not.

[00:26:44]Everything fundamental basics are crystal clear or not clear.

[00:26:50]Anything they want to ask like this always think and answer the things you know 100% correct make sure those things to extra think and answer because if you are believing your answer is 100% correct that means 100% you are in denial immediately when you feel like your answer is correct always remember my rule in life by any time someone ask you a question your answer will decide the kind of respect that person is going to have for you till the end of your life.

[00:27:25]You give 10 answers correct, one answer wrong, your respect level will go down.

[00:27:30]Every answer coming of your mouth coming out of your mouth should be crystal clear correct otherwise take some time and think answer next day answer after 10 days or simply say I don't know but don't give the answer which is not properly thought of once you develop this habit in speaking this develop will automatic this habit will automatically develop for answering the questions in the exam and a silly mistake will not happen clear Wise person, intelligent person are two different things. We have to become wise.

[00:28:06]Intelligence I can develop but wiseness when to answer when not to answer that you have to develop the clear but don't act wise in my class in class answer immediately because time constraint is there outside I'm saying with the people of your caliber or the people below you getting if you want to command the respect every Answer you say, every word you say should be foolproof.

[00:28:40]That means no one should be able to identify any error in what you are saying. And if they identify you can accept it, you can move on. But our objective should be whatever we say is 100% correct to best of our knowledge and thinking. Knowledge is not enough because knowledge means whatever came in your frontal cortex at that time.

[00:29:02]Whatever you have not read from the books is not your knowledge yet. But thinking your own thinking some time has to be given for it. Then only answer it.

[00:29:10]Maybe 1 2 seconds also can be enough. So now we have understood the demarcation of atom molecule properly.

[00:29:18]We understood the meaning of atoms and molecule properly. Can anyone tell me who was the scientist who first time defined the difference of atom and molecule? Anyone know the scientist who differentiated between atom and molecule before that everyone was thinking molecule does not even exist probably or they were thinking atom and molecule are same who was the first time the scientist who first time differentiated between atom and molecule or give the existence of molecule or give the existence of elemental molecule.

[00:30:02]First I explained the meaning of elemental molecule. First I explained that same type of atom can combine with each other. Exactly. Everro was the scientist.

[00:30:15]Aro was the scientist who for the first time defined the existence of a molecule. So the atom and molecule whatever you have just now read the credit goes to Aagedro.

[00:30:29]One interesting thing I will tell imagine you say something correct but people don't realize it right now irritation will come when you know you are correct you 100% know you are correct but remaining people are not agreeing to that will you feel irritated or not will you feel like what kind of idiots there I'm saying correct only listen to me I'm always correct this feeling comes or not have Ro said correct after 50 years 15 kadu after 50 years people started accepting key whatever he was saying was actually correct.

[00:31:17]So today whenever you use au number au will teach us the power of patience.

[00:31:24]If you are doing good work, the world will recognize but not when you want it to be recognized. The world will not recognize your work when you want it.

[00:31:35]Said I'm working right now, my parents are not understanding by Aadro.

[00:31:39]50 years later, next generation accepted the work of Aeadro and today we are learning it. Aadro number in the memory of Aadro reminds us the world will give you your share.

[00:31:56]You don't even know the name of Joseph Prost properly.

[00:32:02]Joseph Prost name you might not have even heard very powerful person of that time but aro every kid knows from class 9th onwards the world recognized the effort he got all the respect but patience was required for it so remember in life life is not going to be fair to you will get your share but not when you want you will get the share of your hard work but not immediately when you want you will get the reward also but not when you Clear to coming to the history of chemistry. Laws of chemical combination.

[00:32:47]Why? Little bit little bit kuncham kuncham. Try to remember the name of scientist also. Try to remember the chronology also because name of scientist and chronological questions are very common in biology.

[00:32:59]But there is no rule in chemistry and physics. They can't ask it. So when next year those questions will come, people will call those questions as highly irrelevant. And I will call those people as in advance. I'm telling because everything is printed in the NCERTT. We are getting the enough time to teach all these things in the class.

[00:33:18]But because of our insincerity, we don't remember. We don't tell.

[00:33:24]Clear? to make sure you have to prepare for every type of paper conceptually strong, fundamentally strong or even wrote mugging who discovered what in class 9th everyone has mugged up JJ Thomson electron James Shedwig neutron 1932 clear by understood 25 this question came not this question other question came that also I will tell you to half knowledge is there this much long keyboard they are typing clear by the laws of chemical combination shall we start by so laws of chemical combination the first law of chemical combination is law of conservation of mass now if you can't remember the whole name of the scientist Remember some trick. The first law of chemical combination which was the base of remaining all the law was law of conservation of mass. So chronologically chronologically means what was first made? Law of conservation of mass was first made out of the laws. And this law was made by one insect lover.

[00:34:53]You don't have to remember the whole name getting ba understood but you have to remember at least bare minimum so that when options will come you can at least remember ant lover one insect lover ant lover the law of conservation of mass can you remember this much name exact name also you should remember not obviously the photo but I am saying if you remember this much also if you remember ant lover also you remember JP also Joseph Frost then also it will be more than enough for you to answer the question in the examination correctly by because spelling to they will not change of the name this much dumb question they will not ask but conceptual question in that little bit of history they can mix up assuming that this much the people would know So you can check here if you remember a n t and l a v o love or love ant lover got the idea by then law of conservation of mass was made by [clears throat] experimental study of dash reaction. They can ask you which reaction was studied for making the law of conservation of mass displacement reaction, disproportionation reaction, decomposition reaction or combustion reaction. So the answer here will be combustion reaction. So this chaa he worked upon the combustion reaction very carefully. He measured the mass of reactant and product and then he gave the theory that mass can neither be created nor destroyed in a chemical reaction. Chemical reaction is very important. Why don't put nuclear reaction in your head? Right now in physics it may come energy mass theorem energy and mass are conserved but right now we are reading the fundamental law of high. I don't I don't care it is correct or wrong but this was the first law clear by this time it was proven to be correct only the mass can neither be created nor be destroyed in a chemical reaction. So for example if you take CH2 double bond CH2 this is ethine ethine and you convert this into CH2 single bond CH2 whole N polythine and I'm saying this conversion was with 100% efficiency that means no wastage mam conversion happened then on converting 30 g ethine dash g polythine is formed say by so here we don't need stochometry and all we know that only ethine is converted to polythine no other reactant so whatever is the total mass of the reactant should be the total mass of the product if total mass of The reactant is 30 g then with 100% efficiency the product must also come out to be 30 g.

[00:38:39]There is no possibility of mass loss or mass gain.

[00:38:43]Say by is the law of conservation of mass clear or not clear by done.

[00:39:01]done.

[00:39:03]Note down then I will go to the next page because sometimes dumb question will come and dumb answer we have to give. So that dumb question and dumb answer we will see in the next page done.

[00:39:26]But yeah now next is dqda dumb question and dumb answer. See why we are writing the examination made by some other person and we can't assume that the person is always going to give the correct question and correct answer.

[00:39:45]Historically neat has proven several times that they give several times absurd answers of the question and then they don't accept their mistake. We are supposed to answer the wrong question wrong. Like this year in geology one question I am coming to know about the Henley's loop which is not a perfectly correct answer as what the subject experts are telling.

[00:40:06]clear. So I'm realizing that they the most probable answer only they are taking and moving on. So such kind of questions I will call as DQDA dda.

[00:40:16]One such daga question is which case violates law of conservation of mass.

[00:40:35]Options are C + O2 give you CO2.

[00:40:41]C + O2 give you CO.

[00:40:46]N_sub_2 + 3 H2 give you two ammonia.

[00:40:51]Number four, none of these or better to say all of these to where the violation of the conservation of mass is going on. Now what is the dumb question and dumb answer? By the law of conservation of mass is a fundamental law. There is no violation.

[00:41:13]But because dumb question dumb answer zone is going on. So in this case people in the neat division especially they teach that in J also theor theoretical topics everyone is like almost same throughout the country they teach that unbalanced reaction and this is complete garbage. It's a very dumb question. I will tell you also why dumb you should understand as well.

[00:41:38]What if a good paper setter comes like the need 26 paper setter? He will completely destroy the mugging of the idiots. We should understand the wrong also in case it comes. But we should al also understand why it is wrong also.

[00:41:51]See unbalanced reaction people teach this thing. Unbalanced reaction law of conservation of mass is not followed. It is only followed for a balanced chemical reaction. So it is balanced 12 16 into 32 total 44. Here also 44 this is 12 + 32 12 + 32 44 12 + 16 28 to by this bhab is unbalanced chemical reaction and in such question where they are asking where the law of conservation of mass is not followed. They are trying to ask you which is the unbalanced reaction.

[00:42:33]Understood. When dumb question will come when they are giving you three four reactions they are asking you where the law of conservation of mass is followed or not followed. So for balanced reaction you will say followed for unbalanced reaction you will say not followed. And that is how DQDA by more dangerous for the country is not al-Qaeda.

[00:42:56]It is dagda.

[00:42:59]Why? When dumb questions like this will come and majority of the public start teaching those dumb question those dumb questions can come in the exams also and then the whole country will produce the doctors and engineers whose brain is so rotten that they don't have a thinking of their own now I will tell you why it is a pathetic question but before that tell me if this question will come will you be able to answer it or not I don't want you to become hero in the exam by the question is wrong. I will not answer their answer. Come out, get the marks.

[00:43:34]Then reach in the system. Re reach and promote in the system and then make sure this dumb question stop coming in future. It will take 10 15 years. Now why is it dumb?

[00:43:45]I want you to conceptually please forget everything. Leave the pen and paper and think with me. Imagine with me.

[00:43:53]Nature is having some rules which we don't understand how it follows.

[00:43:59]One of that rule of the nature is that whenever two reactant will react product will form in that container real life real practical container understand in this container carbon taken O2 taken and let us say it is becoming CO airtight jar will the mass of this container change on this combustion reaction, partial combustion reaction. Will the mass of the container change? Are you getting? I have taken some carbon, I have taken some oxygen, nothing else. I closed the container airtight. Nothing is going inside. Nothing is coming outside. Tell me, will the mass change or not change?

[00:44:47]This container's mass will change.

[00:44:52]Let us say 12 g of carbon I have taken 32 g of oxygen taken and somehow I made sure that it only became CO in an imaginary situation it only became CO let us say will I get 28 g of CO 44 g will become 28 g dieting he will do now if some idiot have written equation wrong. If some idiot have written the equation wrong, does it mean the law of conservation of mass got violated or this person have written the equation? Equation is a representation of the reaction by your representation is wrong. Reaction is following conservation of mass by mass is conserved.

[00:45:45]You are writing wrong you for it's not like now for example sur one person is there let us say sur forgot to write half you think in heaven god will have a round table meeting big problem came pa problem what problem came bro are we made now remember ant lover he was making one law of conservation of mass mass is neither created nor destroyed we remember yes yes yes we all decided the nature will follow Follow the conservation of mass for chemical reaction. Yes, we decided I remember it. What happened? That was hundreds of years back. Now, huh? But in 2026, now Sur forgot to write in his notebook half O2. In place of half O2, he has written O2.

[00:46:29]Yeah. All the god are holding the head. Now we have to change the law. Now our law got violated because sw forgot to write half.

[00:46:43]It is like saying if I am applying 10 Newton action I will get I will get 8 Newton reaction. Is it a violation of action reaction law or is the stupidity of a person who has done a calculation mistake? Let us say you found 10 Newton force and the reaction came 8 Newton or something like this. I don't know that much of physics. I'm just saying I'm explaining you with the example of a law that we all know. So that's 8 Newton came because of calculation error. You forgot to multiply something divide something.

[00:47:19]Will you call that numerical as a violation of action reaction law or will you say uncle correct your calculation by balance balance it balance reaction is still following the law of conservation of mass. Your equation is wrong.

[00:47:35]Are you getting the difference by this question?

[00:47:39]Some of you understood why I'm calling it dumb. I can't expect everyone to understand it. But even if my one student understood that means that one student has got better knowledge and IQ than so many educator who throughout the country and maybe paper setter also.

[00:47:53]I've seen this in some papers as well.

[00:47:56]Did you understand how dumb is that?

[00:47:58]That means today today Sur will do this tomorrow Sur will do this double one more law will come.

[00:48:06]Yeah. Exceptions of the laws will come will come. Yeah. All the all the reaction will behave in the same manner.

[00:48:13]Whether whether Suresh will write this or not on the paper, the reaction will happen in the same manner.

[00:48:20]It will follow the laws of chemical combination whatever are applicable right now like conservation of masses is still applicable. Some laws are proven wrong also. Dalton Chacha was proven wrong. But this was not proven wrong.

[00:48:32]And at least by this equation though not proven wrong.

[00:48:36]By this equation though not proven wrong by understood by is the meaning of violation clear.

[00:48:44]Violation means a natural phenomena not following our law because nature is under no obligation to follow the laws made by human. Again nature is under no obligation to follow our made law. So when we say above principle violations that means some real configurations we have seen in chromium copper or somewhere which are not following what we thought as the law those are called violation the real life scenarios which don't follow the trend those are called violation not a piece of paper silly mistake it's a silly mistake it's a dumb silly mistake in class 6th I will deduct marks in class 6th for balance Sensing this reaction I will not call it a violation.

[00:49:35]Shall we carry on by but again dagda clear by the dumb question dumb answer is very important to clear the examinations not only in India throughout the country these kind of things can happen throughout the world different papers you will see now it's not like sats and all those things are very good every single paper throughout the world you will check they all have some blenders they all are made by humans and humans are going to do blenders Then our job is to make sure if one blunder has happened and we have realized that blunder we should voice our concern so that somehow it reaches to the right people and these kind of stability cannot be repeated in future exams so that at least in our country our student learn correct conceptual things concept this is conceptual thing this was a conceptual fault in the terms of faculties and the paper setters who have given that's why this kind of question got generated Clear?

[00:50:38]Shall we continue to the next example?

[00:50:41]Number two, law of definite proportion or composition.

[00:50:55]Aa before going ahead, I have to show you that paragraph from where some informations we have written in short in our notebook. But make sure that you read this also. So this bisab this law was put forth by this bisab in 1789 performed careful experimental studies for combustion reaction that's why I said combustion reaction reached to the conclusion that in all physical and chemical changes there is no net change in the mass during the process of the NCERTT can also do some typing errors like during duting so it's okay hence we reached to the conclusion ution that matter can neither be created nor be destroyed. This is called law of conservation of mass. This law formed the basis of several later developments in chemistry. In fact, this was the result of exact measurement of masses of reactant and product and carefully planned experiment performed by logistere understood the idea by then our JP came.

[00:51:56]JP had a very beautiful left profile.

[00:52:01]The most uh colorful person I would say was Dalton. You will see the photograph of Dton, you will realize. So he was just like me. Whenever his photo was supposed to be clicked, he always clicked the photo like this.

[00:52:17]That's why he always gave half the law.

[00:52:20]He was supposed to give full law but he gave half law. Which half he gave? Why are we calling it half? That we are going to see now. Ready?

[00:52:31]understood to JP Chacha.

[00:52:37]This law came after that law JP Chacha was around 10 15 years younger than the tent lover getting by. So now what the law of definite proportion is? Now see the law in the words of JP Chacha only. I will not ch change the word at all. So now a given compound always contain exactly the same proportion of element by weight.

[00:53:20]Is it visible?

[00:53:25]I will write here only J. I will write here the space will be also saved. Joseph JP JP stated that a given compound always contains exactly the same proportion of element by weight. Second thing what they can ask you firstly I will explain this later but second thing what they can ask you just like our end lover has worked upon combustion reaction which compound JP Chacha was working to JP Chacha was working on copper carbonate cupcarbonate to be precise cupcarbonate Cu3 this is worked what he worked upon so So he did some calculation. He took two samples of cupriic carbonate. One was naturally found in the form of ore.

[00:54:16]He extracted that. Second he synthesized in the lab. And in both of the cupcarbonate he found the copper percentage.

[00:54:27]So the percentage of copper will be because this whole definition is by weight.

[00:54:33]Law of definite proportion is by weight.

[00:54:36]So percentage of copper by weight will be weight of copper by total weight into 100. That's how you find any percentage also by percentage will be like percentage error is the error upon true value into 100. Similarly any percentage will be that substance that thing upon total into 100. So weight of copper upon weight of copper carbonate into 100 he did he found that the percentage copper came same in natural Cu3 and synthetic Cu3 that means what he's Doesn't matter what the source of the substance is. Any compound whether naturally made taken from Himalayas, think like water, water in Antarctica, water in Vijavara, water in Japan or if ever water is found on moon or Mars or even sun anywhere the water will always contain two hydrogen atom and one oxygen atom. This proportion will always be same irrespective of how you got the water or from where you got the water.

[00:56:04]The percentage of each element by mass will be fixed.

[00:56:11]They have a fixed formula.

[00:56:14]This was said by Joseph Frost.

[00:56:19]clear by now several times you will see that you will hear that I'm saying PF mix don't think I'm not saying prost properly he was not Indian he was French in French their pronunciation is slightly different madame they will not say madam they will say madame frost Anyway, the pronunciation they will not ask but do you realize by this I made you remember he was from France French Crosa Croa have you seen that crossroant you may call it French given in the NCERT obviously given otherwise why will I talk about it's not like he was my friend French chemist clear but what about CO3 chaa he found for copper also carbon also oxygen also I'm just writing here copper assuming that this much to brain you might be having if copper percentage is same then carbon and oxygen percentage is also same NCRT not bought send your uh Google pay number I will send 150 rupees by NCRT next time stupidity will not be coming obviously he calculated every element one example I am giving you of copper clear by understood so one question we can do one question we can do one numerical we can do to understand the importance of this law ready so write Find percent by mass of H of hydrogen in water.

[00:58:34]Let us say the water is tap water or Antarctica glacier water or the ground water or just the tears coming out of your eyes from there. If I distill the water that any water you take the percentage of hydrogen will be same and that percentage of hydrogen will be weight of hydrogen by weight of water into 100.

[00:58:56]Now tell me in [clears throat] H2O there are two 1 into 2 the mass of H will be 2 unit I will say in the next class amu or gram I will tell in the next class depending upon which how much quantity I'm talking about but 1 into 22 2 + 16 I think everyone know 18 will be the mass unit again I'm saying I'm not talking about the unit right now so weight of h will be two total The weight of total water will be 18 into 100 to roughly 11.1% is the percentage of H in any water found in anywhere in the world irrespective of the source.

[00:59:41]So percentage of an element in a compound is independent of It's source and amount amount also doesn't matter whe whether I take 10 g of water or 100 g of water or 50 g of water the percentage of H in any amount of water will be same say by anyone have doubt in this question say I.

[01:00:30]So find percentage of O in a sample of H2O2 or better to write here to confuse you in 18 g sample of H2O2. And before you start solving the question and waste your time, let me tell you this 18 g is a useless data. So why useless? Because the percentage of O you can find directly by their molar masses just like we have found here. And that percentage of the element is independent of source and amount. So whether I give you 18 g or 180 g or 20 g it doesn't matter or 34 g it doesn't matter. Percentage of O will remain the same. So my advice will be for such kind of question find the answer by using the molar masses or molecular masses to try and let me know what the answer is coming. I am waiting for the answer. And don't cheat. Don't use calculator. Do the question by yourself. By crack the exam, not the dreams.

[01:01:58]94.11 someone said did you divide yourself by honestly batana mega did you divide it yourself or without the help of calculator like proper division which we have taught in the previous classes Take divide divide by divide divide divide.

[01:02:45]So percentage O will be weight of O by weight of H2O2 into 100. So I can take firstly I have talk about the molecular mass here. So I will get the molecular mass of hydrogen I will take 1 into 2 plus oxygen 16 into 2. 16 is the atomic mass of O into 2. So 32 + 2 34 34 is the mass 34 amu or 34 g per mole is the mass of H2O2. So H2O2 if I take 34 if if 34 is the mass of H2O2 taken 34 not taken but I don't care percentage is independent of the amount or source. So I am taking 34 because my mathematics will be easier with it. So if I take 34 g of H2O2 in that oxygen will be 32 g.

[01:03:39]Got the point? If I'm taking 34 g of H2O2 in that oxygen will be how much?

[01:03:46]32. If I take this then this much is the O. So then why you are not using this data? Because in 18 g H2O2 how much O there? I don't know. I will have to find it. Calculations become lengthier.

[01:04:00]So this will come out to be as someone rightly pointed 1600 by 17 and when you divide it to roughly 94% will come check by 94.117 but I'm rounding off to 94 say by are you understanding this data should not confuse 2 by this data also same answer has to come but the method will become lengy because if you take 18 g H2O2 in the denominator then in 18 g H2O22 how much O is there when I will teach you in the next class I will teach this also unitary method when the mole concept will start but then the question becomes lengthy we can solve the same question without using much of a mole concept just by understanding the fundamental by whether I take 18 g or 34 g the percentage of O will remain the same. Only thing you have to be careful with is that if you are taking 34 g H2O2 then you should know the weight of O. In 34 g how much is there in 34? Out of 34 32 is the weight of O and two is the weight of H.

[01:05:20]Say by clear. Can I move on further ahead?

[01:05:24]Is this clear or not?

[01:05:29]Is this clear or not clear?

[01:05:39]Now to make the topic interesting I will change the sequence of NCERTT slightly shat interesting remember all this drama forget this drama all this was given by whom? J prost why I'm saying J prost like this why I'm calling JP like this why am I not talking to you like this anymore why I said JP like this why because my side profile is better image in the book from that image in the book what I made you remember is that bhai because this bhaab is having side profile better he gave only half the law of definite proportion sir which half they go now the NCRT states after the law of definite proportion NCRT states law of multiple proportion which was very interesting thing you see now very interesting Okay.

[01:06:52]Law of conservation of mass 1789.

[01:06:56]Then this viceab gave his work year not mentioned but he gave his work. Then multiple proportion came by dalton in 1803. So what is interesting here? See now Dton Chacha is a very old chacha.

[01:07:12]getting by. He gave his theory in 1808.

[01:07:20]Whole dal atomic theory came in 1808.

[01:07:26]Hello. So before giving his theory, the same person has given law of multiple proportion but we'll talk about that in the next class. Our right now concern is why I'm changing the sequence. You will understand. Now I'm going to tell you Gillus's law of combining gaseous volume which came in the same year when Dalton Chacha gave his theory Dalton's atomic theory clear why the Gillus law of combining gaseous volume this is the Gillus law of combining gaseous volume then why because it is half bottom half top I will have to write the whole law myself so I'm writing the Number three, Gillus's law of combining gaseous volume in that combining I will put in the bracket because NCERTT does not use the word combining here. It just uses the gaseous law or galis law of gaseous volume. Now after understanding this by the end of the lecture you will understand why JP chaa have clicked the photograph like this then why is Geros's law of combining gaseous volume when gases react or get produced in a chemical reaction they do So in simple whole number ratio but I'm writing integral ratio integral also you will understand why I'm writing integral.

[01:09:14]It's a positive integer. I could have said whole number positive whole number except zero but I'm writing integral.

[01:09:23]They do so in simple integral ratio of their volumes under same condition.

[01:09:38]Condition means pressure and temperature. So whenever the gases are combining they combine in the simple whole number ratio of their volume. Understand now when N2 react with 3 H2 to form 2 NH3 what Gilos is saying firstly what is the stochometry concept I will tell here only why to waste our time stochometry concept is wherever this kind of a balanced chemical reaction is there if baron reaction not there I will not even apply stochometry because the reaction is not balanced but if the reaction get balanced balanced you balance it then you will get 1 N2 that means 1 mole N_sub_2 1 N2 here means one mole N_sub_2 plus means reacts with what is the meaning of plus reacts with how many H2 3 mole H2 so 1 N2 plus 3 H2 means 1 mole N2 reacts with 3 mole H2 Arrow means to form or to produce 2 NH3 that means two mole ammonia. This is what we are going to learn in the stoometry in future.

[01:11:03]What our galosis cha is saying.

[01:11:11]He saying let us say 132 to 1 liter N2 reacts with 3 liter H2 to form 2 L ammonia. This is what our gills law of gaseous volume is there. GL L mean Gossess law getting by this is our Gillus law of combining gaseous volume. He's saying that whenever the gases are reacting this is also gas. This is also gas. This is also gas. Whenever gases are reacting or produced, they always react and produce in a simple whole number ratio. That means the ratio of nitrogen is to hydrogen is to ammonia reacted and produced is 1 is to 3 is to 2.

[01:12:03]Did you understand the law? He simply saying whenever the gases are reacting, they react in a simple whole number ratio.

[01:12:15]Say by clear or not clear this is the next week's levers but because if you will be comfortable from today onwards in this stochometry part my life will become very easier. So that's why I thought why not tell here only you'll be busy in the gillsense law. I will silently teach his stochometry and move on.

[01:12:51]Understood by shall we carry on? N2 H2 ammonia 1 is to 3 is to2 volume ratio.

[01:12:58]Hello.

[01:13:01]Done.

[01:13:04]Done. This is the gillus law of combining gaseous volume. Very simple law there. I will just show you what is written in the NCERTT and the example of NCERTT. The reason I have not given that example of H2O2 H2 is because they are considering water vapor which can be confusing at times. So I will teach that here only. He said when gases combine or produce in a chemical reaction they do so in a simple ratio by volume provided all the gases are at the same temperature and pressure. For example, when hydrogen and oxygen react to form water to 100 ml hydrogen was reacting with 50 ml oxygen to form 100 ml water.

[01:13:47]How can you explain it? We all know how to explain because we know how the reactions are written to H2 O2 water.

[01:13:59]How many O2? 1 H2 half O2 gives you H2O to 100 ml H2 50 ml O2 half 50 ml O2 1 H2O to 100 H2 to 100 H2O to 100 ml hydrogen giving 100 ml water vapor this is water vapor that's why I don't want to use this example because they mentioned water vapor but here they are writing water and water is a liquid for liquid we don't apply this to vapor you should write it because the mean vapor but then you will misunderstand it unnecessarily. I'm taking that example N2 H2 ammonia which we know are gases under normal pressure and temperature.

[01:14:41]So what he found that the ratio of hydrogen and oxygen combining to form water is 100 by 50 that is 2 is to1 over this is the end of gillus law understand beyond that whatever the paragraph there gillus is not contributing to it. Gillus law is this much only whatever you are doing with the moles in future you can do the same thing with volume for gases you can say one liter of A react with one liter of B to form 2 liter of C for example let's say A plus B gives you 2 C to 1 liter A plus 1 liter B gives you 2 L C to in the place of that 112 stochometry you can use the volume this is what Gillus says have said mean this is what he meant now what he said was very simple thing whenever the gases react they react in simple ratio whenever the gases produce they produce in simple ratio that means 1.1158 liter react with 3.7982 liter simple ratio will come 1 is to2 2 is to 1 3 is to2 1 is to 3 these kind of ratios the gases will react and this ratio in the terms of volume he has defined are you understanding what I'm saying by is the idea clear what he's saying he's saying whenever gases are reacting they react in the simple ratio of volume hello say by CO2 become CO carbon solid plus CO2 gas become to CO gas to when 100 ml CO2 reacts or 1 liter 1 ml when 1 ml CO2 reacts dash ml CO is produced assuming 100% efficiency say by carbon is solid I can't apply the gillus law on this I am saying when 1 ml CO2 gas react 2 ml will be produced to say correct or not correct by so in place of one mole I can use one ml directly for gases say by is the gillos law of combining gaseous volume on the practical sense clear or not Yeah.

[01:17:37]Done.

[01:17:39]Now, now listen carefully. I'm winding up the lecture by focus. Now understand when N_sub_2 react with H2 to form ammonia say case number one case number two case number three I'm taking three cases when one liter nitrogen taken how much nitrogen taken one liter these are the volume consumed I'm writing here the volume consumed in three different cases When one liter nitrogen taken how much liter of hydrogen will be consumed?

[01:18:23]Three to say when 100 ml was taken how much ml H2 will be consumed. When nitrogen taken 100 ml to hydrogen nitrogen 1 to hydrogen 3 when nitrogen 100 ml taken to how much ml hydrogen will be consumed 300 ml this we know huh we know this now we know because we know the balanced chemical reaction then he did what he did was he did the first experiment when one liter nitrogen consumed he realized in the experiment experiment key. After the one liter nitrogen got over, 3 liter hydrogen also got over.

[01:19:06]When 100 ml nitrogen got over, 300 ml hydrogen got over. And when let us say 10 ml nitrogen got over 10 ml, he found that 30 ml of hydrogen was getting over.

[01:19:22]So he did three experiments. Let us say he did many experiment actually has did many experiment but let us say three exper experiment he has done to what the ratio of nitrogen is to hydrogen came in case number one 1 is to3 how much nitrogen is to hydrogen came in the case number two 1 is to3 how much nitrogen is to hydrogen came in the case number three 1 is to3 by this he has experimentally found we have written this thing by stochometry. But this Visab have experimentally found that the ratio of nitrogen and hydrogen reacting to form ammonia is a fixed integral ratio of volume.

[01:20:17]Say by are you getting what he found experimentally? He's think he's not able to understand when I'm taking one liter then hydrogen 3 liter consumed when 100 ml taken then 300 consumed when 10 ml taken then 30 ml consumed he understood after that after two three experiment aa the ratio of nitrogen and hydrogen reacting to form ammonia is same in all cases and this is called definite proportion by volume. This is also definite proportion. Fixed proportion fixed proportion coming not coming.

[01:21:00]Every time 1 is to three reacting every time just like in water what I said in water I said there are 2 H1 O everywhere in the world. In the same way throughout the world anywhere N2 H2 react to form ammonia.

[01:21:17]Galus has found the ratio of N2 and H2 reacting is a fixed whole number ratio and he did not say this thing but other people realized Gillus have just now discovered again the law of definite proportion by volume.

[01:21:39]Are you getting by what he discovered again?

[01:21:44]law of definite proportion but this time he has discovered in the form of volume say by clear or not clear so actually gillus law is base of what law of definite proportion by volume.

[01:22:19]Are you understanding the point I'm saying?

[01:22:22]Joseph Frost have done wonderful job but he restricted himself. See he restricted himself. I'm taking the NCERT extract only. He restricted himself to only the law of definite proportion by weight.

[01:22:35]Half a story told. remaining half was told by Gillus and interesting thing when Gillus discovered this now he also did not realize he discovered see I said now Gillus's law is over here after that what happened Gillus discovery his discovery of integer ratio 1 is to 3 1 is to 3 1 is to 3 or 2 is to 1 2 is to 1 2 is to 1 every time coming actually the gills says discovery of integer ratio in volume relationship is actually he also did not realize other people understood actually it is the law of definite proportion by volume.

[01:23:18]The law of definite proportion stated earlier was with respect to mass.

[01:23:24]And this explanation was given by my favorite the epidome of patience Aadro in 1811.

[01:23:38]Getting by that we will learn in the next class. Key how Aadro explained it.

[01:23:43]Why the Aadro law is important. We will also learn that Aayadro have received his credit of the hard work of the extreme intelligence of understanding something that no one understood at that time after 50 years.

[01:24:03]Clear? If our marks start coming very good after 5 month that much patience we can have here. when Aagedro waited for 50 years to get the recognition that he always deserved and now we know Aadro number Aagadro number Aadro number we don't know JP number we don't know AL number getting by understood the idea but before going ahead did you understand we have law of definite proportion this is by mass and law someone asked you who gave the basis of law of definite proportion by volume.

[01:24:44]Who gave the basis of law of definite proportion by volume? And if your answer is JP wrong answer will be bakquas.

[01:24:56]Answer will be Gillus.

[01:25:00]Why? Again read Gillus says discovery of integer ratio in volume relationship is actually the law of definite proportion by volume to who gave actually the law of definite proportion by volume by mistake because in his definition you will see he never talked about definite proportion. He said simple ratio. He never said simple fixed ratio.

[01:25:28]That later on we realized after his experiments Gillus says whatever he's saying that can be written as N2 and H2 will always now you tell me now you know now 1 N2 react with 3 H2 always the ratio will be 1 is to 3. And now you call this ratio as the stochometric ratio. But when stoometry was not defined these scientists have done the work and figured out the science for us that's how the stochometry what we are going to read now came into being say by is the fundamental clear is the fundamental clear you can scan this QR clear next class we are going to wind up the laws of chemical combination and enter into atomic and molecular masses done by revise the notes again ba I can complete this topic within 1 hour also you also know that laws of chemical combination is not that much big but if we have to learn conceptually NCRT we need time and energy both so I need your support today revise properly why whatever I have taught you today properly revise again and again revise clarify the doubts if they are there but then only move on to the next topic Understood by understood I saw I saw in the app right now in the app only one exam has happened clear by so right now they are sharing on the status and all of the people administrators who have uh given the admissions to you but this will be as soon as online class will stop on YouTube and it comes in the app all the information starts coming in the app only. So don't worry about it. Right now on YouTube community those get posted. What problem comes? I will tell you people are just viewing.

[01:27:24]So it's like a channel. If you're not subscribing it problem that will come is that you will not get the notification of community.

[01:27:31]So you have to go and check in the community of YouTube again and again whatever the status has been uploaded because there all the things are mentioned. Assignment obviously will have to be given by the faculty separately that I will ask how he has said but timetable uh slavers all those things I have also checked they are mentioned over there getting by just that you are not seeing it because you are just viewing this channel and leaving so that is not administrator's mistake no getting by yeah but anyway I will try to ask them to streamline this a little more so that your channel of communication become established if any principle or vice principle is in your contact check their status. You will get regular update also done by are you uh in contact with any administrator or someone who has given you the I'll ask them I'll ask them to upload the time table in this clear in the YouTube also I will check one more time if they have uploaded or not but in case in case by the evening it is not streamlined my number is there with you you can message me then I will again ask them to get the things done okay by generally By the evening they will wind up the things once once I will ask them after the class. Okay. By tella bye-bye. Revise the notes properly. Revise the NCRT properly. Keep learning boring things also in the interesting manner and the selection will automatically come.