chemical bonding part 10

追加: 2026-05-13

[00:00:00]now i just uh finished now uh i told you that there are many compounds which have got less than eight electrons in the outer moisture like lcl three bf three bcl3 etc which are quite stable similarly there are compounds which have got more than eight electrons in the outer motion like sf6 if7 ah pcl5 which are also stable there are also compounds which have got eight electrons in the outer muscle they are also stable there are also odd electron pairs got it they are also stable how it is so now we are going to explain it first we will come to those particular compounds which have got less than eight electrons in the outer motion like bf3 alcl3 3 b cl2 how it is now one person was there his name was sigvik s i d g w i c k sig x theory of maximum covalency sigmix theory of maximum coherency now sigmic suggested that it is not necessary that all the elements in the periodic table should obey the octet rule it is not necessary according to him listen carefully according to him he said that that is hydrogen should have one electron in the first period in the second period the maximum number of electrons in the outer muscle can be four not age similarly for the third and fourth period the maximum number of electrons should be six and fourth period onwards it should have the octane structure again i repeat according to sigmic as we say that either it should always operate out of the plate then and then only it will be stable just now it is having less than eight electrons how is stable for it you might be thinking so sigmic said that it is not necessary that all the elements in the periodic table should be the octet structure it is not necessary not at all like for the first period hydrogen let us say should have one electron if it is having one electron on the outermost cell stable no need to see there is obtained duplicate or what similarly for the second period if it is having four electrons with the outer moisture then it's at the best all right if it is four then set twist it similarly third and fourth period should have six electrons in the outer muscle not eight six if it is six table fourth period onwards we will see octet rule so octet rule comes from fourth period onwards this was the theory given by sigma now how far this theory is true whether it is true for all the compounds are not not shaped all right it is not only for some of the compounds you can try it out and see it is being true so in this way whatever it is theory of maximum covalency goes in this particular manner at least it try to solve the problem that why the elements are still why this compounds are stable even if it does not over the opera structure even if it has got less than eight electrons in the outer motion if it is not true for all but it is true for some that is we can say that next comes the next theory it comes your surgeons surgeons view of singlet this is singlet linkage surgeon's view of singlet linkage you can see that now surgeons what he said is that all right in some book you will find it is written s u g d in some it is s u d g not it is nothing but a russian mean so hence the spelling differs in this particular way like mendel if meant to live and some do you will find f in some book you will find v got it so it depends so that there is nothing to worry about it now surgence view of singlet linkage now this particular theory it is put forward for those compounds which have got more than eight electrons in outer motion more than eight electrons so like pcl5 sf6 if7 in this way all right for those compounds we can say that clearly now ah that is what sahaja has to say surgeon says that after obtaining that is suppose a compound is a it is sharing electrons once it attains octet structure all right once it attains the octet structure by sharing of electrons once it attains output structure then the remaining what you can say the electrons which is being there between the two elements it will form not a full bond it will form a half bond which is called a singlet linkage i will explain with an example just listen surgeon says that that after it obtains the octet structure let us say sulphur is having six electrons it requires two more so two more electrons it gets gets from two fluorine so this fine remaining what you can say for fluorine sulfur what it will do sulfur it will not share completely that is the sharing is going to take place but not completely what is that that is a half bond will be found that is a singlet linkage is being formed all right so hence it is being said that surgeon's view of singlet linkage now let me explain you with the help of a example then you will come to know that what is this singlet linkage or half bond now see here properly see i am giving example of sf6 sulfur hexafluoride all right by this surgeon says that that none of the compound disobeys octet structure every compound obtained what you can say obeys the octet structure none of the compound disorder is obtained structure see sulphur i am taking it here now this is a circle i am doing it the sulphur is having how many electrons outermost shell six i am making six cross okay you can make dot also exactly one two three four five ah let me take the five here and six here now what you do is that this is for one fluorine this is for the second fluorine this is for the third fluorine this is for the fourth one this is for the fifth one this is for the sixth one one two three four five and six you can see that okay now fluorine is having how many electrons in the outermost cell cell one two three four five six and this is seven see here now count it sulfur was having six six cross one more dot is added so sulfur has got how many seven fluorine has got seven dot one two three four five six seven and one cross so it is how many eight so sulfur is seven and fluorine is eight this chlorine is stable correct now coming to this fluid one two three four five six and here it is seven see here 7 so in this way this fluorine is also stable 7 plus 1 cross stable and sulfur is now stable sulfur is now stable what see sulphur was having 6 cross two three four five six and two dots six plus two eight that so it is a full bond full body means here sulphur this was one flory and this was one fluorine it got full pot clear now you see what happens now fluorine what will happen is that one two three four five six and the seventh will be inside so fluorine it does not share its electron with sulphur but sulphur shares its electrons fluorine fluorine does not share you look here the fluorine the electron is where it is within chlorine atom we have done it i have not done it here in other cases here so fluorine is not sharing with sulphur but sulphur is sharing this electron with fluid all right as a result what happens is that fluorine becomes eight seven dots is there one cross eight and sulfur is already eight it does not require any more electron so hence i will how will you show this you will show it in this way this is half a bond same thing for this chlorine so one two three four five six and the seventh one is here see carefully the seventh one is here so it's fluorine seven and one cross each sulphur was already now sulphur this dot does not come here so the sulphur number of electrons is not increasing see sulphur number of electron is remaining same till now it is eight only six cross and two dot till now it is eight this dot are not done here or i'm not done here so sulphur it is not increasing mind it sulfur remains eight only so another half bond you get it clear same thing for this chlorine one two three four five six and the seven again same thing another half bond is there you can see it fluorine seven and one more cross from fluorine that is nothing but uh from sulphur it is h all right it forms half a bond here also one two three four five six and seven all right here also half bond so ultimately what you find ultimately there is four half bonds and two full bonds so hence sulphur it is eight only competency one two three four five six you can zoom it and you can see it all right and here it is sulphur but you can say two electrons is there a fluorine two electrons is same so six plus two eight after that any electron you can find from chlorine no the fluorine does not share with sulphur but sulphur shares with fluorine in this way sulphur remains octate only and fluorine also attains the octet structure so this is called as singlet linkages half bonds known as singlet linkage okay in this way surgeon says that that none of the compound disobeys the octet structure all the compound obeys the octet same thing with xenon fluoride same thing with pcl5 same thing with zenon oxy flow reducing you'll be getting it all right i hope you understood all right better you do some more examples you'll understand it now in this way clear so you can do it and you can find it out that it does not disobey the octet rule so you are having full bonds then after that we are having the remaining is your half bond okay so this is called a sachen's view of singlet linkage by this we are able to explain but the odd electron is there that i will explain it later on little bit later on wait so in this way we have explained it all right by the cigrix theory of maximum covalency and the substance we have seen great linkage the compounds which we say does not over the output structure but they have given their own theory to explain this particular compound fine now we will come to the lewis dot diagram lewis dot diagram now lewis dot diagram is what just we will represent here the valence electron with dot that is called as limits dot diagram the valence electrons will represented by dots okay for example fluorine has got seven electrons so one two three four five six and seven this is seven dots this is a diagram for fluorine atom okay now for oxygen one two three four five six oxygen for hydrogen one dot clear in this way every element we can represent it the valence electron by dot this is called lewis dot diagram for elements now next is we'll come to the lewis dot diagram for compound how to draw it for compound for example water for example like charged particle radical like carbonate iron cni diamond for example acid like sulphuric acid nitrous acid phosphoric acid like ammonium radical how do you draw it okay here also you can draw the odd electron and i can show it to you so now we are going to draw the lewis dot diagram for the compounds this is for the element it's quite simple it's quite simple it's very easy just you will show the valence electron to the help of doms that's it you can see seven dots now children listen carefully got it listen it very carefully because things are getting tougher for you now all right so hence listen it very carefully understand it very carefully when you see the video when you see this particularly any doubt is there you pause it go back again come forward and see it repeatedly then only you'll be able to understand it all right yeah now let us say i i want to draw the lewis dot diagram for carbonate ion co3 c o three two minus carbonator so what are the steps i should follow to draw the lewis dot diagram listen carefully and write it down first you need to find it out the number of valence electrons in carbon and oxygen along with these two electrons two minus means one two electrons extra isn't it you need to draw the number of what you can say valence electron in carbon and oxygen you need to draw it and after that uh you need to add it up all right first you need to draw first you need to add then you will draw it all right yeah fine so carbon the first step is that add the total number of valence electron present in the given species add the total number of valence electrons present in the given species along with the charges along with the charges along the charges means this one if it is two minus means two electrons more so plus two i'll add it suppose it would have been here two plus then two electron less minus two i have done suppose if nothing is there like co2 neutral so only to add only will add up the valence electron okay like so total number of valence electrons total number of valence electron in co 3 2 minus this is how much carbon it is six sorry carbon uh atomic number is six it is four electrons is there in the outer moisture balance you understand outer moisture oxygen it is six six into three eighteen plus two two electron industry so eighteen plus two twenty twenty four so we got twenty four electrons now the second step is find the pair we will find the pair of valence electron pair of electrons so it is 12 12 pairs it will be because 24 by 2 it is 12 eighths so we got 12 pairs so we have to arrange the 12 pairs where you will arrange the third is you draw a rough diagram which is called as a skeletal diagram means you just arrange it roughly like carbon will be there in the middle definitely the central atom and this oxygen here this oxygen here and this oxygen here definitely orients you know i will put an oxygen here here three oxygen you have to put at three corners finish so this is the skeletal diagram the third steps and the fourth step is that you need to arrange this 12 pair of electron that is the most important one you need to arrange the 12 pair of electrons around carbon and oxygen without violating the octet rule that's a very important point to remember it you need to arrange this 12 pairs of electrons around carbon and oxygen without violating the update rule you need to arrange this 12th place so see here carefully all right now this particular thing you have to develop by doing practices on it the more you practice the more perfect you will be now see here you can start from anywhere from carbon oxygen anywhere you can start from now suppose i start from oxygen here one two three four five six because oxygen has got six electrons i put let me put it six and see what happens now here it is now this two let me put it here all right because it will be sharing now now same thing this oxygen also has got six maximum one two three four and five six now this oxygen also has got six one two three four five six all right now see what is happening what is happening see here so how many pairs we got it one two three four five six seven eight nine pins three pairs more i have to arrange it but without violating the update structure three more pairs so the total twelve pairs are there how many pairs i got see one pair two pair three pair four five six seven eight nine pairs i got it three more pairs without violating the octet rule here what you find is that none of the element is stable now none okay let me put here a pair here let me put a pair so what it becomes here one two three four five six seven eight this oxygen is stable even carbon is also stable you see carbon one two three four five six seven eight stable so this carbon and this carbon and this oxygen is stable now okay now you need to make stable this oxygen so here you put one plate and here you put one pair you have to count it and you have to do it you need to have patience understood you need to have patience initially might be you will not be able to do but don't lose the pieces otherwise what can be done so in this way now count it one two three four five six seven eight nine ten eleven twelve c twelve base averaged all right so i started from somewhere i started from oxygen first i put six six electron because maximum can be six by taking that this one pair of electron will be with carbon then i saw nine ps is there then i thought that i have to arrange three pairs how to do without violating the octet so i put one pair here by doing so this carbon this oxygen is balanced done now two more pairs i can't put it here this two one pair here and one carrier by doing so what will happen carbon it will increase so hence i put it here done all right two minus now what is the structure here so you can see this one pair means one bond one pair of electron means one bond here two pair one bond two pair two bonds and this now you draw the unpaired there is these are pair now this this is a paired electron this is pairing with carbon so it is pair and this one is unpaired we can say unpaired you show by the help of dots this is only known as lewis dot diagram we can say that clear so here this this this and here also this you can see one two three three here here one pair have done it we have two pair of vanity and two more electrons here here one pair have done it here and here one two all right and this you can see that two minus this is the lewis dot diagram of carbonate iron in this way we need to find that we need to draw the lewis dot diagram okay thank you very much