CHM 102/CHM 121

インデックス作成: 2026-05-15

[00:02:50]Good morning everyone.

[00:02:52]Well, welcome to today's um class on CM 102. If you can hear me clearly, my voice is clear. You can hear me, send a yes into the chat room. And those of you on YouTube, if you can hear me as well, send a yes into the chat room.

[00:03:23]If you can see my slide, you can hear me. Those of you on YouTube as well, you can send your comments to let me see if you can indeed hear and see my slide.

[00:03:35]that I'm sharing at the moment.

[00:03:42]You can see my slide. You can hear me.

[00:03:45]Those of you now for those of you that have been writing your names and matric number on the in the chat room, this is not acceptable. And I'm sure by now you should understand that we don't take your attendance on in the chat room. The chat room is for response to questions in the class.

[00:04:19]Now I'll give you privilege. I love the fact that some of you are very smart by naming yourself with your full name and your matrix number. That is the best way to pick you and to mark you present in the class. So for those of you putting your name and matric number in the chat room that is not acceptable. You can rename yourself to capture your matrix number for easy identity. So for those of you that are putting your name in the chat room, you will not be marked present like that. You can what you can do is make sure that you use your real name.

[00:05:03]You can rename yourself to capture your matrix number. Some of you are very smart doing that already and that is very easy for us to mark you present in the class.

[00:05:25]>> Okay. So last time we met we talked about [clears throat] the history a brief history of organic chemistry. How the scientist you know came out from you know the oldest time 19th century 20th century and even in the 21st century. We looked at that last time. We also um looked at the importance of organic chemistry in medicine, in agriculture, in energy, in materials, biological understanding as well. And of course, we looked at some um practice question during the class. Now, for those of you that sent in your um class assignment very late, it will not be assessed.

[00:06:21]It is only during the class time that you can send in your assignment. So, the same thing is going to happen today. We still have some set of practice question after today's uh very short class. Then on Monday we will have a very full and well detailed class with a short test at the end of the class.

[00:06:50]So I asked us to do something last time that you should look at graphite diamond and ferine [clears throat] and tell us the relationship or what you can say about them. So what can you say about each of them based on your findings? I'll be waiting for your responses in the chat room before we go on into the um explanation.

[00:07:17]What can you say about graphite? What can you say about diamond? What can you say about ferins?

[00:07:39]They are allotropes of carbon. So do you think they are the only allotropes that are available for carbon? Do you think they are the only allotropes available for carbon?

[00:07:58]cuz I think I gave this information last time and I asked that we are going to um look at that today. They are not.

[00:08:08]So can you mention any other one you can you know before we move on Okay. So it shows that a lot of you are know making findings and you can have information about the other allotropes of carbon. So for the purpose of the class today we'll look at the introductory aspect of the allotropy.

[00:09:24]We'll look at the different allotropes.

[00:09:26]We look at their basic properties.

[00:09:32]I hope those on YouTube can hear me.

[00:09:35]Yes, I can see that some of you are responding well. You can also rename yourself to capture your matrix number for the purpose of the class. Of course, you can change it after the class if you don't want it like that. So, allotropy is the existence of two or more different physical forms of a chemical element in the same physical states.

[00:10:02]Now if I want to look at it in another way, I can say that allotropy is the property of some chemical elements to exist in two or more different forms in the same physical states.

[00:10:21]I'll take that part again because that one is not captured in your notes. I can say that allotropy is the property of some chemical elements that make them exist in two or more different forms in the same physical states.

[00:10:39]So be because carbon has a valency of four. I think I mentioned that in the last class and it has this um incredible ability to bond to itself and that term is called what? The ability of carbon to bond to itself to form a longer chain is described as what?

[00:11:04]Very good. So it shows that you are in the class and you can relate with what I've been saying so far. So even though what we are talking about even though all these are made of pure carbon atoms they have an internal structure that make them to be different from each other. In fact they are not in any way close. They are different drastically and that leads to you know different physical properties.

[00:11:34]It's just like a twin you know each of the twin have their own identity.

[00:11:42]So the same thing you know is applicable when we are talking about alotropy.

[00:11:49]So we have a typical example of the primary allotropes of carbon and for the purpose of this class we would focus on diamond graphite ferines but I would also highlight other allotropes of carbon for us.

[00:12:07]So the very first one as seen on the slide is diamond the first allotrope of carbon that I'll be looking at. So I will do a short um description of what diamond looks like.

[00:12:22]Diamond is a crystalline form of carbon and in its structure each carbon atom has um a coalent bond. So each carbon atom is coalently bonded to four other carbon atoms in a rigid take take note of that in a rigid and threedimensional tetrahedral latis. I'll take that part again. Diamond is a crystalline form of carbon in which each of the carbon atom is covealently bonded to four other carbon atoms in a rigid threedimensional tetraedral latis and I'm very sure that you can see please can you still see my slide please is the is the slide moving Tell me what you can see at the moment.

[00:13:24]You can see the slide that talks about alotropy and then graphite diamond and ferin isn't it?

[00:13:41]Okay.

[00:13:44]So please take notes as I'm you know giving you the information.

[00:13:54]I've talked about diamond being a crystalline form of carbon and each of the carbon atom has a particular bond called what coalent bond.

[00:14:08]It has an hybridization that is the mixing of the orbitals. It has the hybridization of sp3.

[00:14:17]It has the hybridization of sp3. The mixing of s orbital and 3p orital in sp3 format.

[00:14:30]According to research, we are meant to understand that this diamond is the addest known natural substances and it has a very high refractive index. I'm going to be highlighting all this property in another table that will make it easy for you to understand.

[00:14:51]So the very high refractive index makes it an electrical insulator because it it has no free um deoized electron.

[00:15:04]Why do you think it has no free deoized electron? I've mentioned it in this class today. I mentioned that because it has what? It is coalently bonded to four other carbon atom. In what form?

[00:15:24]In what form? I mention in a rigid structure. Thank you. in a rigid threedimensional tetrahedral latis.

[00:15:44]So we will look at the application of this um diamond for example as a result of the very high refractive index. It is an electrical insulator because it has no free deoized electron.

[00:16:09]So the application of diamond is something that you can relate with well for example in jewelry, industrial drills, cutting tools. Can you mention other um primary uses of diamond? You can mention one or two based on the information you are given last time in the class. I gave um an assignment that you should read about alotropy that we'll be reading. I will be looking at today. So apart from the application in dr cutting tools in industrial drills, which other application can you think about?

[00:16:50]You can put your response in the chat room. I will pick your name and mric number from there.

[00:16:59]Very good. Even in abbrasives.

[00:17:05]So while we have information a short at least a brief information about diamond the next allotrope of carbon that we'll be looking at is graphite before we close today we would look at practice question and also look at the we look through what we have done so far today so by um a short summary we've looked at the definition of alot allotropy We have looked at different allotropes of carbon. We have mentioned each of them. Now we are looking at them one by one. So the next one is graphite.

[00:17:48]If you relate graphite with diamond graphite is arranged in a flat you can see the structure on your screen [clears throat] is arranged in a flat twodimensional layer of hexagonal rings.

[00:18:05]If in the next class I'm going to bring a model to show you what this actually look like. You can see it right on your screen. The the uh picture of graphite is there. But I will show you the live picture that I will model for you in the class and you'll be able to see and relate well with these shapes that I'm talking about. So is arranged in a flat two dimen dimensional layer of hexagon rings. If you see it is a six membered ring. So why the coalent bond within the layers are very strong. The coalent bond within the layers are very strong compared to diamond.

[00:18:53]And these layers are held together by weak Vanderwars forces.

[00:19:00]Very weak Vanderwars forces so to say.

[00:19:02]And this allow them to easily you know slide past one another. And you can relate well with the application of graphite in even in your house. Compared to diamond graphite is SP2 hybridized.

[00:19:19]So hidation in the structure of graphite is sp2 compared to diamond that has which hybridization which hybridization did I mention for diamond?

[00:19:34]SP3. Thank you debura. So the in terms of their property if you want to compare them because you are going to give me a feedback I'm going to ask question at the end of the class and you give me a feedback on that. So in terms of their property if you compare them to diamond they are soft.

[00:19:55]In fact according to um reports about graphite they are slippery as well and they are good conductor of electricity.

[00:20:06]Maybe I should even use excellent conductor of electricity because each of the carbon atoms leaves one electron deoize to move freely between the layers.

[00:20:21]between the layers.

[00:20:49]So the primary application of graphite you can find application in the pencil we use the lead pencil the lubricants even in electrodes in battery. Can you give example of typical battery that make use of graphite?

[00:21:10]Give an example of batteries that make use of graphite. The one you can relate with.

[00:21:25]Yes.

[00:21:26]Any battery that you can relate with.

[00:21:30]Yes, that is correct. Even the um lithium battery, even the car battery, you can relate well with them. So if in any test or exam you are asked to give this information you should be able to give information.

[00:21:47]When I give you application I give each each of the alotropes of carbon three application. So you should be able to give me more more application of each of them at least up to five. You should know up to five. Some of this application is captured in your notes. I decided to stay in the in this particular slide. So you can take your notes and then you'll be able to answer your questions well during the um class exercise.

[00:22:18]Another allotrope of carbon is graphine.

[00:22:23]I won't go to ferin. Yes. Is graphine is spelled g r a p h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h h e n e. G r a p h e n e is graphine.

[00:22:41]This graphine is a single one atom but a thick layer of graphite. You can see that it is like a sub is a sub under graphite but it has also been identified as an allotrope of carbon. So graphine is a single one atom six layer of graphite and in fact it is essentially a single sheet of carbon atom that is packed in a very tight form into a two-dimensional oncomb lactice. Now because I said that graphine is a sub under graphite. What do you think the hidization will be? It will be what type of hybridization? What is the hybridization of?

[00:23:38]Very good.

[00:23:40]SP2.

[00:23:42]Very good. So the the hybridization of graphine is SP2.

[00:23:49]And despite being a thin um structure is it has also been reported that it is about 200 times stronger than steel and this also this graph extraordinary electrical and thermal conductivity as well. You can't be surprised because of course it is a sub under graphite.

[00:24:19]Typical example of this graphine in day-to-day activity you will find one in solar panels this reinforcing composite materials as well. And if you imagine all these advanced electronics you will find graphine present in them.

[00:24:41]Another one that I want to share with us is carbon nano tubes. Carbon nano tubes is otherwise called C NS.

[00:24:53]C NTS. I'm not going to include the graphine the carbon nanot tubes in your notes. So you should take notes in the class.

[00:25:04]You should take note in the class. It's carbon nano tubes CNTs.

[00:25:10]These um carbon nano tubes they are essential sheet of graphins that are rolled up into a very you know easy microscopic cylinder. They are mostly fine to behold. They have this um single wall or even some of them are you know multi-wall in structure.

[00:25:34]Again this is a sub under graphite. So what do you think the hybridization will be?

[00:25:46]SP2. Thank you. So they possess very no great tenzine strength and unique electrical properties.

[00:25:57]Sometimes they act either as metals or even semiconductors depending on how they are rolled. If they are rolled they can you know function well as a metal.

[00:26:08]In other application they can function well as a semiconductor and just from the name they have found application in nano technology in sport equipments.

[00:26:24]Can you mention any sport equipment you think this kind of allotrope of carbon can be found because I mentioned that they have application in nanotechnology in sport equipment for example before I mention the example the one you can relate with very good in the dumbbells or all these lightweight bike frames all these lightweight bike frames they have this um composition and even in aerospace engineering they have also found application in that sector. So another important one that I want us to look at before we go into a short summary because I want you to understand this part and then have some questions and a typical type of method in which we can ask question based on this um topic.

[00:27:31]We want to look at the ferins.

[00:27:35]The ferins. You see [clears throat] that you have the basic structure of all the ones I'm talking about on your screen.

[00:27:43]You can see them. The graphite, the diamond, the ferine. So, we are going to focus on them. I will be able to make good comparison between the graphite, the diamond, and the ferin.

[00:27:58]Of course the technique the tennis racket. Thank you. We have found application in that as well.

[00:28:08]So now let's go into the ferin. This ferin is a bulky balls as seen on the slide is discovered in the year 1885.

[00:28:20]You can take a short note.

[00:28:23]They are cage like molecules of carbons.

[00:28:27]So what you are seeing on the screen they are cage- like molecules of carbon atoms and they are arranged in a spherical shape as seen or ellipoidal shape or even tubes.

[00:28:43]The most famous um ferine is the one that is referred to as the B mistine.

[00:28:52]It has up to 60 carbon atom.

[00:28:57]arranged in a series of hexagon and pentagons.

[00:29:02]I will take that part again. I mention that ferins otherwise sometimes they refer to it as bulky balls.

[00:29:13]As bulky balls but of course as a chemistry student you should be able to tell us that it is ferins.

[00:29:21]It was discovered in the year 18 um 1985 and these ferine are cage- like molecules of carbon. So you can if you are asked to describe it for example you can be given different information as option your ability to identify the right one will depend on your understanding.

[00:29:48]You can't see my slide.

[00:29:51]Can you see? Is it moving?

[00:29:54]Can you see this?

[00:30:00]Can you see my slide?

[00:30:02]Those of you on YouTube, good.

[00:30:15]Those of you on YouTube, can you see my slide? Is it changing?

[00:30:25]Very good. So, let us continue.

[00:30:31]So, I said it consists of up to 60 carbon atoms and it is arranged in a series of hexagon and pentagons.

[00:30:43]Now let's do a short comparison.

[00:30:46]Let's do a short comparison that you have on your slide at the moment. So we've talked about five of them.

[00:30:55]The amorphos um allotrope of carbon. This one does not have a defined structure.

[00:31:05]And in terms of property, they have a variable adness and reactivity.

[00:31:10]And of course in activated um carbon and charcoal they have found application. So now you have up to how many allotropes of carbon that we have discussed today? Can anybody tell us how many allotropes of carbon have we discussed today? Can you mention them one after the other? You have it on the screen. And the ones that I didn't mention that I didn't put it on the screen, but I mentioned it in the class. Can you mention them?

[00:31:49]Mention them.

[00:31:56]Diamond, the graphite, the graph, the ferin, of course, amos. What about the last one? I mentioned one again.

[00:32:22]>> I mentioned one again and I've not seen anybody mention it. What about the carbon?

[00:32:33]I'm just saying carbon CNT. So, how many all together did I mention?

[00:32:41]Very good. So, you should have this information, please. But we are focusing on the one you are seeing on the screen.

[00:32:49]So I can twist the question to capture all the allotropes of carbon that we have so far. So please take note of that and of course their application their application is also very important.

[00:33:14]So in summary, you have the summary on your screen right now in terms of their structure, property, the uses right on your screen.

[00:33:28]So what are the relationship between organic chemistry and this allotrope that we have just mentioned?

[00:33:36]The very first one is that it influences the properties and reactivity of carbon based compound. If you notice while I was explaining the different allotropes of carbon, you would um see that I was mentioning their properties.

[00:33:56]I was mentioning the hybridization.

[00:34:00]For example, the properties of graphite and diamond compos of carbon and they are different and unique due to their distinct structure.

[00:34:09]So this knowledge helps chemists to understand how different arrangement of carbon atoms can lead to a range of organic materials with unique property and with unique application. And that was why as I was mentioning those allotropes I was mentioning the the application that we can relate with and I also ask us to add to the list so that you can actually relate well with what I am talking about.

[00:34:40]So this is a pictorial representation of the beautiful part of a diamond. We have looked at the structure.

[00:34:51]A pure diamond according to research is colorless.

[00:34:55]So you may have color. So if you have a color, it means that it contains some what?

[00:35:09]It contains some impurities. Thank you.

[00:35:12]So if you are asked that what is the color of a diamond and you have colored colorless now I'm giving you this question because I don't know depending on what um you have in the um synopsis of the questions to be set. So if you are asked that diamond is dash colorless colored and other options will be there. So which one are you going to choose as your right answer?

[00:35:52]For example, it is colorless.

[00:35:57]But if the information is detailed enough and say that pure diamond is or say a diamond is colored due to the presence of dash. You already have the answer. You may also be tested on some other properties. It has a melting point of 3500°C.

[00:36:24]Pure diamond is also transparent. You can see it on your slide is transparent to X-ray and it has high refractive index as I've mentioned it before. So I'm giving you the value of the refractive index now which is 2.45 is the refractive index of diamond. 2.45 is the refractive index of diamond.

[00:36:53]I also mentioned that diamond is SP3 hybridized. This is it. You have a bond length of up to 0.154 nanometers and has a bond angle. So you see that I'm I've gone from the general information now I'm streamlining it into what you need to understand and know for the purpose of your exam. It has bond angle of 109.5°.

[00:37:23]Of course, the hybridization you have it you have that information also that the bond length is up to 1.54 armstrong and also you have the bond energy of 347.

[00:37:44]So in diamond for example each carbon atom utilizes all its four aair electrons in bond formation.

[00:37:56]I'm going to take that again in diamond each carbon atom utilizes it four a pair electron in bond formation and these bonding electrons are localized and due to this information diamond is a bad conductor of electricity. So before we close I am rolling out the question. We will stop here and we'll continue from there next time when we look into detail about graphite. I've given us an overview of all of them. Now we are going into the chemistry of each of them. We have looked at the chemistry of the diamond. So we'll also go through the chemistry of the graphite. You have it right on the screen. But I will also repeat this particular information in the next class.

[00:38:50]I hope you have gotten some additional information today.

[00:38:56]Are you ready for the question? Do you want me to share the questions now and then you'll be able to answer the question? I won't ask you what was not captured in the notes.

[00:39:10]Those of you that are still writing your name, I will still pardon you for today.

[00:39:27]Next class, you will be penalized for it. You know, I promise that I'll penalize you today, but I'm not going to penalize you. Stop writing your name in the chat room is meant for response to questions in the class. We have another method of getting your name signed to mark your attendance. Your name is being marked as you respond to questions in the class.

[00:40:08]Okay. So, if you can see the screen right now, let me know. If you can see the screen I'm sharing right now, please let me know. Can you see the screen that contains the questions?

[00:40:28]Okay, I'm going to stop share and I'll share again.

[00:40:50]Can you see this screen right now?

[00:40:55]Good. So, what do you think is the answer to the first question?

[00:41:08]What do you think is the answer to the first question?

[00:41:26]Yes. What about the second question?

[00:41:39]Yes.

[00:41:43]What about the third question?

[00:41:52]Very good.

[00:41:56]Let me move the question.

[00:41:59]Can you see question four? Is it Is question four clear to you?

[00:42:10]So, what is the answer to question four?

[00:42:27]Very good. What about question five?

[00:42:32]I'm sure you can see question five.

[00:42:38]What is the answer to question five?

[00:42:50]>> Now I want you to answer question 6 to 10. You send it the way you sent the last one. It will only be captured right in the note. You don't have to send me answers to question one to five.

[00:43:04]send you in your answer in the chat room, including those on YouTube. Write it. Write your answer.

[00:43:16]Write your answer from question six. I'm I'm scrolling to question six. I believe you can see question six. And then now to question seven.

[00:43:31]I will not repeat that. Question eight, you have it. Question nine, you have it.

[00:43:39]So, what you are going to do now is that you write out your answer on a sheet and put everything together as one chart, as a single chart. Listening to instruction is part of your learning. So, you should learn how to, you know, get information and process it correctly.

[00:44:01]You are to write the answers from number six to 10 together as a single chart.

[00:44:11]So your answer to question six, your answer to question seven, your answer to question 8, 9, 10 must be together. You do not have to share your answer from question one to five because we have done that in class.

[00:44:29]So you would say question six is a for example, question seven, question eight, question 9 and 10. For example, Nataniel did the correct thing. Nataniel goodness did the correct thing. That is what I expect from every other person. And of course he has his matric number written also as part of his name.

[00:44:56]So that is what I expect from every other person in the class. Your matric number must be there with your name.

[00:45:07]So I'm going to give the next 4 minutes for you to send in your responses. And then yesterday three more minutes.

[00:45:54]We have two more minutes.

[00:46:23]So I'm going to give opportunity to one or two persons to give us a short summary of what we have done today.

[00:46:33]If you are willing to answer the question, raise your hand. I will allow you to talk.

[00:46:51]you have the floor.

[00:46:56]>> Um, good morning ma'am. So, um, we talked about allotropy. At first we said it is the existence of two or more uh carbon compounds in different form but in the same physical state. So we move to diamond. We said diamond is a crystalline form of carbon and uh it has all its carbon atom coalently bonded to four other carbon atoms in a rigid threedimensional tent triendal latis and it is sp3 the addest known substance with no localized electron. It is used for cutting jewelries because of its high refractive index has a melting point of 3,500 and has a refractive index of 2.45.

[00:47:43]Before we move to stop there, we will give room for Abdul Salam to talk.

[00:48:01]>> Abdul Salam, you have the floor.

[00:48:26]Hello. Good morning, ma'am.

[00:48:28]>> All right. Go on. Um, aim.

[00:48:33]>> Yes. Good morning, ma'am. My name is Olu and um, continuing from where the last person spoke, we continued on the other tropes of carbon including graphite, amorphos, and graphines, then also CNTs, which are carbon nanot tubes. So graphite is the second um allotrope of carbon. Graphite is graphite is sp2 hybridized with one free localized electron which accounts for the conductivity of graphite. It can conduct metals. Um it is also used for making um lead pencils and it is a good lubricant.

[00:49:12]Then next we went to graphins. So graphins are sub graphite. They're also sp2 hybridized because graphites are also sp2 hybridized. They are one carbon thick layers of carbon. They are one carbon thick layers sheets which can be um bent and folded to make dumb balls um gym equipment and rackets. Okay, we can stop there because of our time. I have another class. But it shows that you are getting information, isn't it? You are getting information and then you can relate with what we are talking about with with something around you. So we're going to continue with that. Even though the you know higher you go the more complex it becomes. These questions gives you an idea of how the questions can be asked during your exam. Am I going to repeat this question that I've given to you? The answer is no. But is it going to be part of the um the way I'm going to say the question is it going to capture all the things I've taught you? Of course, yes.

[00:50:26]But I can just twist the question to, you know, include other information that has been shared in the class. So, have a wonderful day. Enjoy your weekend and see you in the next class.