Roadmap Explained! Inorganic Chemistry Part 1, 4e | Cengage JEE Advanced | Dr Balraju Karri

Added: 2026-06-04

[00:00:00]Hi, this is Dr. Balaji Curry, the author in organic chemistry S. Chand & Company, India. In this video, I'm going to explain you the complete road map of inorganic chemistry part one of the fourth edition of inorganic chemistry where we introduce this road map for the first time.

[00:00:17]Let us see the road map how we are going to start with and where we're going to end in the 11th standard.

[00:00:23]And we begin with we are going to start here with periodic table evolution and the periodic laws that you studied in 10th standard and are starting from Dobereiner and then a Newlands comes saregama padanisa like octaves and then you know uh Lothar Meyer and then comes Mendeleev and Mendeleev actually gives a very proper arrangement with atomic masses then you know uh then we change to atomic number and get some modern periodic table. All these things already studied in the 10th standard. We're going to see here once again as a revision and then we'll move ahead with electronic configuration, electronic configuration, and the periodicity and how the electronic configuration of an atom has a direct straightforward connection with the periodic table.

[00:01:05]Like for example, in atom there is a shell and in shell you have a subshells s p d f. s p d f subshells are basically you see in the periodic table as s block, p block, d block, and f block, right? s subshell has two electrons and s block has two groups. p subshell has six electrons and p subshell has six groups. In this way there's a great connection between electronic configuration and the periodic proper periodic table.

[00:01:31]Right? All these things we'll see here and then we'll move ahead in the road and we see here periodic trends and reactivities. Different periodic trends like atomic size, ionization enthalpy, electron affinity, electronegativity, all these things and exceptions.

[00:01:46]Obviously, you know chemistry means there must be exceptions in it. The exceptions of beryllium or boron, nitrogen and oxygen, all these things we will see here.

[00:01:56]And then we'll move ahead with the chemical bonding and types different chemical bonds. You know, covalent bond, ionic bond, and also something called dative bond or coordinate bond you see in the 11th standard. Ionic and covalent already I seen 10th standard, right?

[00:02:10]Here you see a new bond called as coordinate bond or dative bond. So, how this bond is formed, what are the conditions for it, and there's so many questions on that you'll see in this particular topic. And then you will move on to the next topic called as molecular geometry and hybridization.

[00:02:26]Just like you have hybridization of different plants you do and sometimes we do hybridization of what do you say, the horse and a donkey and you get a mule.

[00:02:34]Right? Kachar, they say kachar or kichar like that. And here we do hybridization of orbitals over here, subshells of you know, S and P.

[00:02:42]Hybrid, you get SP hybrid orbital. 1S2P, you get SP2 hybrid orbitals. 1S3P1D, SP3D hybrid orbitals. This kind of hybrid orbitals are formed. Why they are formed? What is the, you know, reason for it and you know, there's a need for it. All these things you will see here and because of hybridization different geometries called linear, trigonal planar, tetrahedral.

[00:03:07]All these geometries and the shapes based on the lone pairs present on the central atom. All these hybridization, geometry, shapes, you'll see in this topic. And then you will move on to the next topic there's bond parameters and molecular stability. In the bond parameters, you know, bond is there.

[00:03:24]A bond has different parameters. Bond order, number of bonds between two atoms, the bond length, and the internuclear distance between two atoms in a molecule, and the bond energy, amount of energy required to break this bond.

[00:03:36]Right? All these parameters. And important is bond angle, the angle between adjacent bonds. How to judge, you know, who has a higher bond angle, who has a lower bond angle, and based on what factors we are going to judge theoretically, and how this, you know, bond order is going to affect the chemical reactivity.

[00:03:55]This all parameters are going to see in this particular topic and then after understanding this you go ahead with MOT. Now because the bonds have formed, the molecule is done. Now MOT is molecular orbital theory.

[00:04:08]Just like atoms have orbitals, when molecules form their own orbitals. Once the molecule is formed, the same atomic orbitals they don't retain. They form molecular orbitals called ammo and bommo. It's anti-bonding molecular orbitals and bonding molecular orbitals.

[00:04:24]They have different energies and how they work, all these things we'll see here and application of MOT is you can understand the bond order between any molecule of course atomic number or Z equal to number of electrons was less than equal to 20. For a diatomic molecule you can find the bond order.

[00:04:42]And also you can know which molecule exists and which does not exist. These things also you can judge with MOT and whether the molecule is paramagnetic getting attracted toward the magnet or diamagnetic. All these applications are very very important from examination point of view. You will be going to see here in MOT.

[00:05:00]And after that we are going to enter to the new chapter. Again the block chemistry is going to start over here.

[00:05:05]Beginning with the hydrogen chapter.

[00:05:06]Hydrogen is very special you know. You don't know where to put this hydrogen.

[00:05:10]Most of you see periodic tables they put somewhere up and somewhere here, somewhere there.

[00:05:15]It's not clear because hydrogen has the properties similar to group 1 as well as similar to group 17.

[00:05:23]Alkali metals and halogens and some properties are against them.

[00:05:27]Some are similar to them. I'll be confusion about hydrogen. You will see what are those confusions of hydrogens why it is not placed properly and ultimately it is being placed in the group 1.

[00:05:37]And the position of hydrogen is one thing and then you know this it forms hydrides. Whichever element you react with hydrogen forms hydride, right? It forms compound both with the metals and nonmetals. So what is the behavior of this hydrides and what kind of hydride forms? Ionic hydrides, covalent hydrides, interstitial hydrides, and who forms this? And who are the exceptions?

[00:05:57]Beryllium, magnesium.

[00:06:00]All these things you'll see in this topic, and then you move ahead.

[00:06:04]Very important compounds of hydrogen upon the hydrides, which are good reducing agents, is water and hydrogen peroxide. So, hydrogen peroxide is unstable because of which it will decompose to again water, giving out nascent oxygen because of nascent oxygen hydrogen peroxide becomes a very good oxidizing agent. Not very good, but it's a good oxidizing agent. You can say mild, you know. H2O2 is also used as a mild antiseptic.

[00:06:30]And water, you know, water is two types of water.

[00:06:33]Soft water, hard water. Hard water is not very hard, but it has so many minerals and salts in it. Because of which it cannot be used for drinking purpose. How to convert this hard water to soft water? All these things we're going to see here in this topic. And after learning all these things about hydrogen and its compounds, we're going to move on to the first block, that is S block. In the S block we get the first group called as alkali metals. Not an alkali, it is alkali metals. Group one, that is Heli Na Ki Rab Se Faryad, or you can say some mnemonic you understood like this, you know. Heli Na Kabar Se Farar, you know. These kind of elements are hydrogen, sodium lithium, sodium, potassium, rubidium, cesium, francium.

[00:07:17]The group one elements alkali metals, what are their properties? Physical properties, chemical properties. Are they going to react with oxygen? Are they going to react with nitrogen? If they react, what kind of compounds they form? Now, you know, nitrogen reacts with group two elements and form the respective nitrides. Magnesium nitride, calcium nitride, strontium nitride. But this nitrogen don't react with group one.

[00:07:40]Group one, they do not react with nitrogen to give the nitrites. But of course there are exceptions in chemistry. You see lithium reacts with nitrogen to form lithium nitride. Why so? I say lithium is Lilly and magnesium is Magubai. This Lilly behan and Magubai has an affair because of which that is called as diagonal relationship. Because of which group one lithium is reacting with nitrogen like group two magnesium. There are many reactions like that. And if you want to know what are those reactions, you read this book, this chapter. And here we see go all these things over here. And the different compounds of alkali metals and as well as alkaline earth metals.

[00:08:24]It forms different salts, important compounds of uh sodium, calcium, magnesium.

[00:08:29]We're going to see here and the properties and then we move on to the last chapter of this particular book, part one. That is P block. And in this uh part we see only 13th and 14th group. 15th onwards we're going to see in the part two in the 12th standard.

[00:08:46]See in 13th, the most important element is boron. We see boron family and these are electron deficient molecules because 13th group they have outermost three electrons. So they're electron deficient. They form three bonds. Right?

[00:08:58]Six electrons, less than octet, electron deficient molecules. And boron has really amazing compounds, you know, like it forms diborane. And diborane forms a new kind of bond. You must have heard first time. It is called as banana bond.

[00:09:12]It forms banana bond. It's also called as three-centered two-electron bond. Likewise, you know, boron has a very uh different kind of molecules. It forms an acid called orthoboric acid, H3BO3. And generally if it is H3BO3 it is supposed to lose three hydrogen ions, but it does not lose a single H+ ion. Still it's an acid. How it is? You must understand here, right? So then we move on after the special compounds of boron, you move on to the carbon family and you see carbon carbon is very famous. You know, carbon has allotropes like diamond, fullerene and graphite. And most often uh students think the most stable allotrope of carbon is diamond, but it's not.

[00:09:57]It's graphite, right? You see all these in this particular chapter of carbon and carbon and upon carbon even silicon is very important. You know, silicon you use in as a semiconductor device and most of electronics is because of silicon. So all these different compounds silicon and carbon, their allotropes, isotopes, you're going to see in this carbon family chapter. And this is how you end the first part of the inorganic chemistry. The next video we will explain about the road map of part two.

[00:10:27]Thank you.