CHEMICAL BONDING | LAST MINUTE REVISION | CHEMISTRY | AAU CET 2026

[00:00:00]Hello. Uh, you know, you need or chemical bonding chapter as a a silo.

[00:00:04]Okay, same things I'm going to bond and all right. And um I buy a revised the college like a bold help of a book. Okay. Uh, chill out start guru chemical bonding. What is chemical bonding? The attractive force uh, which holds more various chemical constituents together in different chemical species. Okay. Like uh, at a atom or species here that people going to stable that people going to that magic people could could bonding or okay. And those bonding are known as more chemical bonding. Now, first [snorts] uh, to my approach going to display to my coastal and coastal Lewis approach as well. Okay. Coastal and Lewis as well. And uh, Lewis as well as well as to my Lewis dot structure.

[00:00:41]And uh, what is this dot? These are nothing but the valence electron. Okay, valence electron if you don't understand me okay to complete them. Okay. And these two chlorine you know they you know they are there at the electron you know they sharing on this side. Uh, done.

[00:00:54]I had to get them in structure uh, Lewis dot structure this is okay. This one to my molecule but I am sorry. H2O and see the all the all other the atoms molecules they complete their uh, that one uh, octet. Okay. Octet method eight eight electrons complete quality leaking to my hydrogen to my that uh, duplicate complete quality. Okay. I don't want to do that in my opinion again like they are bonded with a double bond. But that pair of one pair of electrons like that I'm sharing on that again. Double bond over that the two top pair of electrons sharing on that again.

[00:01:29]This one a single bond. Wait wait wait.

[00:01:32]Sorry. First one is uh, first one is to my single bond over I don't know that to my electron sharing on that again.

[00:01:37]Double bond over I don't know that again. Electron to my sharing on that again. Triple bond over. Okay.

[00:01:42]In the same way to my oxygen to my double bond form over with each other.

[00:01:46]And to my O3 ozone molecule and ozone molecule or to me at that it is structure over and this is a resonance this one is stabilized structure over. Okay.

[00:01:55]Uh, and these are the this is the chart from NCERT. Now, NF3 NF3 a bonded uh singly with uh three fluorine fluorine atom, okay.

[00:02:09]bicarbonate or single bond charge is okay. And this is a ion H and O 3 has This is the structure.

[00:02:25]Um Okay, and now Yeah, uh this is the my H hydrogen atoms in uh against the configuration of helium, okay.

[00:02:36]And the my basically uh this structure know this structure is based on the my this one inertness of the noble gases.

[00:02:43]Uh again the my CO CO Uh see a triple bonded uh bonded triply with oxygen uh the my NO 2 minus is at the end the my double bond or possibly negative charge is in a formal charge. A formal charge Um um Like Man low oxygen atom one money lay so and this one two and this one three. Now, oxygen one not other total formal charge is plus one, okay.

[00:03:22]a three number oxygen atom the my minus one, okay. Yeah, just about and Now, incomplete They have uh not completed their octet, okay. But uh eight electrons Uh the first one is lithium chloride then uh this one BeH2 that is all uh BCl3 that is all AlCl3 or the my BS3 Uh these are all the examples from NCERT.

[00:03:48]Now, the my all the electrons especially all the electron with love Uh I mean that odd number of electron with love uh matters uh odd number of electron present as it is. And all that is it NO2. Then that's it. Expanded octet matters more than eight electrons in other valence shell or present as it is.

[00:04:05]PF5 Now, lattice energy. What is lattice energy? To me other uh to me other lattice structure, okay? I mean other lattice uh solid structure also to be structure also to be there uh like um that this one ions are break or what you say, I don't know. To me other other ions are break or what you say, I don't know. To my other energy to be that is known as the lattice energy, okay? Uh and this is a ionic solid. Now, bond length.

[00:04:32]Again, to my NCERT diagram right? Uh I will go by there.

[00:04:37]Uh this one uh this one uh this one uh atom I mean bond bond for a little kid. You have to measure bond to make form with it. It is bond length.

[00:04:47]That is center by your center like this one this one distance above that is known as the bond length. You see again key acid key acid R equal to RA plus RB, okay? R equal to RA plus RB radius of A plus radius of B. Done. Um now, bond angle. What is bond angle?

[00:05:03]I see to my hydrogen or uh not hydrogen to my water molecule or bond angle 104.5 degree. It is to my NCERT to make it easier, okay? Now, bond order. Bond order matters uh to my bond order is nothing but to my uh that molecule to my get that uh bond there bonded to you as it is, okay? Nitrogen to my uh three bond with uh three uh bonds here they uh bonded to you as it is. To you other to my total bond order key over to my three or O2 O2 molecule two bond order. Done.

[00:05:31]Now, Now, come to isoelectronic species have uh uh identical bond order, okay? To my other uh like what you say uh bond order uh similar to what you equal number of electrons count or to my number of electrons are same or what but they are isoelectronic species other 1 and 2 c o r n o + bond with 3 now resonance I come this is the o3 molecule ok o3 molecule resonating resonating structure ok resonating structure and this is what this is the resonance hybrid ok and then c o3 2 - 2 - 2 - 180 structure and these are all from NCERT ok ok the dipole moment dipole moment what is dipole moment and hydrogen fluorine measure measure this is electronegative electronegative ok fluorine of course fluorine fluorine is the most electronegative element in our periodic table ok he had to share pair of electrons this is the tendency I said the fluorine attract 12 and then that is all ok my name dipole moment the fluorine water water water oxygen oxygen of course oxygen right the oxygen dipole moment of hydrogen and dipole moment is a vector quantity right but I mean addition quality check but I mean yeah parallel shifting yeah but it will and this is the final dipole moment ok that and now BEF2 beryllium fluorine to make electronegative and BEF2 has has a linear structure ok I see fluorine basically like the dipole moment from beryllium to fluorine although it cut cut cut cut cut cut this one over the mu equal to zero dipole moment zero means what nonpolar molecule and BF3 again check the BF3 trigonal planar structure I know the BEF3 yeah yeah but it will be directed towards fluorine now it will be directed This one. Okay.

[00:07:51]Uh This one.

[00:08:10]Now, Okay.

[00:08:14]Uh this one nitrogen or nitrogen and I know basically directed in the same direction. On the and FC the dipole moment Okay.

[00:08:39]I Of course, since like more or less like Okay.

[00:08:49]NH3 dipole moment VSEPR Vesper theory.

[00:08:56]Vesper theory valence shell electron repulsion theory. Okay. I valence electron Okay. Either lone pair lone pair electron bond pair electron. Okay.

[00:09:10]and hope Okay. Now, the basically lone pair bond pair repulsion bond pair bond Okay. Now, come molecules structure bond angle to my 180° structure B E C L 2 trigonal planar linear trigonal planar bond angle 120°. Simple. I had it all.

[00:09:41]The structure give over SP 3 is a tetrahedral. Okay, tetrahedral I had it all. Um Bond angle is 109.5°.

[00:09:52]And this is what? This is what? This is nothing to my trigonal bipyramidal, okay? Uh check the mark.

[00:09:59]Uh and it goes like this, you know?

[00:10:00]Yeah, big head.

[00:10:04]Now this three forms are to a planar.

[00:10:07]Trigonal planar.

[00:10:11]Simple to my trigonal bipyramidal. All right. Our example PCL5. I done. And this is the other one NCERT one of the chart. Uh these are also NCERT in line, right?

[00:10:21]Now this is the NCERT one of the chart.

[00:10:23]I see. The linear one bond angle is 180°. Our example of BCl2 or HgCl2 or the trigonal bi- Uh trigonal planar one of the bond angle 120° over, okay? Uh and the example is BF3. And the my tetrahedral Uh the my example is CH4 or NH4+.

[00:10:39]Okay, tetrahedral over. Our bond angle 109.5°. Out of the my ideas, I see. I had the my pasta pasta uh key uh atom, okay?

[00:10:48]Though First of all trigonal planar The my trigonal bipyramidal form over, okay? Example is PCL5 now. Again the my octahedral. Octahedral is nothing but first of all to me square draw over.

[00:11:03]Square or side of the corner side I had it over I had it over the my question. The my study by science order order. Okay. Uh octahedral octahedral. These are what the my these are uh These are basically the my the molecular geometry.

[00:11:19]Okay. Then uh okay. These are the shape.

[00:11:22]I check.

[00:11:25]The my lone lone pair of his I know. The my lone pair of his I know. The my lone pair of his I know. The my lone pair of his I know. The my lone pair of his I know.

[00:11:33]The my original Okay. Now sp3 trigonal planar Right.

[00:11:52]Simple band.

[00:11:54]Example of Okay. SO2 and O3. Now sp3 sp3 hybridizes dices What is this? This is nothing but the trigonal pyramidal at a pyramid shape pyramid 107, okay.

[00:12:22]sp3 hybridizer dices at a minute a little bit okay. One lone pair little lone pair.

[00:12:29]little lone pair to by the okay.

[00:12:31]to by the AB I band structure band structure I am prime example here H2O I one 1 2 3 and 4 What's that?

[00:12:48]Okay. And now come to this. What? And this is sp3d. Okay. sp3d but love to make it a side and take it all a 3 4 and 5 Can you get a primary structure primary structure geometric trigonal bipyramidal bipyramidal I Okay.

[00:13:23]This is C 4 nothing but C 4 structure I am prime example here SF4, okay. Done. And now uh You have to What is this? This is nothing but T shape. Okay, T shape. Our example of Clf3, okay. Done. And now the uh sp3 octahedral model. Okay, octahedral shape of octahedral geometry to me.

[00:14:07]Okay, done.

[00:14:20]Key hole into square pyramidal I will guess it by pyramid method.

[00:14:26]That's why it was square pyramid molecule, okay. Example of Brf5. And come lone pair. Okay, do structure shape simple lone pair simple square planar molecule, okay.

[00:14:49]Xef4, okay. Fc molecule is xenon. Xenon F4, okay.

[00:14:54]Balance bond theory, balance bond theory question.

[00:14:58]Like uh is based on the balance bond theory is based on the knowledge of atomic orbital electronic configurations of element are uh to my the overlap criteria of atomic orbital are to my hybridization of atomic orbital. To my basically nothing. Basically to my data like uh atom pass bond to what I always say, okay. You have to do my formation of hydrogen bond the asset. I do my H2 formation of H2, okay. Formation of H2.

[00:15:23]I check the data to my hydrogen rule.

[00:15:32]And what is this?

[00:15:36]Right?

[00:15:41]Now, Did you have your subsist other a lowest energy over and this structure is very much stable.

[00:15:56]H2 gas H2 molecule form If you have distance to get I will anybody said and I see both highly increased with that, okay? Then, now orbital orbital overlap concept uh Yeah.

[00:16:18]hybridized orbital form over See, SS orbital to my head-on overlapping SS overlapping and uh to my S and P orbital uh this one um What? head-on overlap SP overlapping, okay? I will PP head-on overlap over PP and to my PP overlap side to my sideways overlap sideways overlapping This is the pi bond, okay? Uh done.

[00:16:46]And now, come to this one.

[00:16:49]I know Uh which one is going to overlap bond form over simple positive or in phase overlap same structure plus plus we have say yeah, for same uh a same uh sign not same structure, same sign to the uh overlap bond form over, okay? Then, I see all the uh this one of the same sign. On the other hand, plus minus to my overlap uh form bond form over, okay? I will Yeah, there >> Yeah, that's the first of all the overlap and I okay.

[00:17:29]And you had it to my shape of molecules that I have hybridization type.

[00:17:44]Yeah, example.

[00:17:47]Then and come to multi molecular orbital theory.

[00:18:03]molecule and atomic orbital to my combine bonding molecular orbital antibonding molecular orbital, okay. I bonding molecular orbital in the lower energy always what the ticket with the bonding the bonding one is more stable unstable I don't the bond order check first of all the nitrogen 14 electron in the highest bond order which is three, okay, which is three.

[00:18:38]I suppose the oxygen bond order given the two bond order, right? And the bond order in is inversely proportional to bond order to my human come bond order to my okay. Then and magnetic nature magnetic nature that I do my Yeah, that I do my all the electrons molecules. All the electrons molecules that I do my paramagnetic paramagnetic over over the even electrons that can be to my human over diamagnetic. Yeah, that I do my the exception that I do my O2. Over the O2 also to my yeah, yeah. Even electron that can be leaking O2 is to my paramagnetic, okay. And to my also to my helium plus helium not plus two helium to H E2 to number exists not correct you can your bond order to my zero is that okay? And to my hydrogen hydrogen bond or what I will say last time hydrogen bond is formed when hydrogen to my F O N or without F O N or what do my first is that okay?

[00:19:25]Hydrogen when when present with F O N then the bond is the bond form is called to my hydrogen bond. Okay, we are done with the chemical bonding and CRT you get I see that we are here we almost and CRT cover for I do so okay. Then I hope you all understood bye-bye.