CHM365 REVISION CLASS

Added: 2026-05-05

[00:01:05]Hello.

[00:01:08]Can you hear me?

[00:02:29]Please um let's introduce ourselves.

[00:02:32]Your name, your department.

[00:02:34]So let's know how many of us are here.

[00:02:36]Your name and your department please.

[00:02:37]Very important. I need us to introduce our your name and your department.

[00:02:43]Let's let's do that in here.

[00:03:11]Just type it on the chat box. Your name and the department.

[00:06:32]All right. Like I said, we are 20 we are 20 persons here.

[00:06:39]Everybody needs to introduce themsel, right? If you know you cannot introduce yourself, your department, you can just leave the live. I just need to know who and who is actually joining us in this class. Your name and your department please.

[00:06:57]This is very important. I believe you can hear me. Your name and your department is very important. Let me know the percentage of people that we have here.

[00:07:14]5 minutes for that.

[00:08:04]Right.

[00:08:11]So having said that um this class we want to look at I would have used my board but I feel this one will be much better since we'll be solving past questions as well. So in case anybody asks questions now before now in class we've done um we've done substitution we've done elimination and I sent a video in for rearrangement.

[00:08:32]Basically today's class I want to talk about free radicals. Okay. Now first by definition by definition free radicals are reactive intermediates.

[00:08:58]By definition, free radicals are reactive.

[00:09:14]Intermediates that have odd.

[00:09:28]or unpaired elections.

[00:09:34]Now, example of free radicals are basically you can see something like you know when we say intermediate intermediate is usually something that is most likely formed before a product is formed. Let's say for example something that is in between a reactant and a product. Okay, if you're going to a three-story building and you're coming from the ground floor, you must first of all pass the middle floor before you get to the top. All right, so that middle floor is basically an intermediate.

[00:10:05]There is no how you can get to the top without passing through that guy. So in chemistry we have you know three major types of intermediates.

[00:10:13]We can have a carocation, right? You know, a a cation that is um an atom that has a positive charge. You can have an anion, an atom that has a negative charge or you can have a radical, an atom that has a dot, right? So if you look at this we said they are reactive intermediate that have odd or unpaired electron. Normally electrons paired electrons are always two and these are even in number. So when we say unpaired it simply means instead of being two that guy will be one and not just that and not just that it is odd right? One is odd three is odd and the rest.

[00:11:13]So in exams most likely what are they going to ask you? they could ask you to we're going to see past questions much later, right? Although I don't really have past questions. Um I don't have past question. I usually use those um the ones from class people usually give to me. So please please if you have past questions, yeah, could you just send it to my WhatsApp? Okay, I will actually access it through my phone. So that's basically the definition of free radicals. So another thing you need to note is that number one they are very very unstable right note free radicals are very unstable highly unstable let's use the word highly and they are very reactive because they are not meant to stay in that form all right high highly unstable Number two, they are very reactive.

[00:12:22]So take note of this that just in case you're being asked, is a free radical a reactive intermediate? Of course, it's very reactive. It's highly unstable. So it cannot stay like this. Once it is formed, it will always want to react with something else. It's a must. Once it forms it always want to react with something else. That's very imagine somebody you know pressing your neck and asking you to stay like that for a very long time.

[00:12:51]You cannot actually stay like that. You actually want to stand up or stretch up stretch yourself. So something that is highly unstable is very reactive. Okay.

[00:13:01]Something that is very very stable is very unreactive.

[00:13:05]So for example now if you're broke if you do not have money right you're unstable small they vex you can actually come off somebody's teeth but if you're very stable like you're very fin you have enough cash you know people just do stuff you can just easily ignore it but if maybe if you're if you're broke you don't have money at that moment you'll be very angry so that's how it is now let's proceed. Now remember it I just said that some free radicals are very very unstable. However, some can be stable. Some free radicals.

[00:15:30]Sorry for that transmission. Breaking transmission.

[00:15:39]All right. So, please can you hear me?

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[00:16:29]All right. So, all right. I like the energy. I like the energy. I like the energy. Please, if you can hear me, drop a thumbs up.

[00:17:29]Okay. So, let's let's continue.

[00:17:38]So, I said some free radicals can be stable.

[00:17:42]Remember I said free radicals are basically unreactive um reactive intermediates right that have odd number of electron.

[00:17:53]This characteristics or this character is what describes a free radicals right reactive intermediate that have odd or unpaired electrons. Okay.

[00:18:07]Now I told us one of the few characteristics of free radicals is that they are highly unstable. Unstable simply means that they do not exist like that in nature. Right? It's just something you have to go through before you get to the final product. So the word intermediate something that is standing in between a reactant and a product. And not just that we also have another type of intermediate in organic chemistry. It can be positively charged.

[00:18:34]It can be negatively charged or it can just be a dot. Okay. Now, the one that is positively charged is called a cation. The one that is negatively charged is called an ion. The one that has a dot is called a free radicals.

[00:18:48]Now, I said that these free radicals they are they can be stable. They can be stabilized. Naturally, they are unstable.

[00:18:57]Right? Just like somebody that do not have money, that person can actually have money. Do you understand? So when something is unstable, there are things you can do to that stuff to either temporarily make it stable or permanently make it stable. Right?

[00:19:14]Whether it's temporal or is permanent.

[00:19:17]Stability can be achieved in one form or the other. So we said that some free radicals can be stabilized due to the following.

[00:19:31]Due to the following, right? What and what can make a radical to be stabilized? Number one, the localization of the unpaired electrons.

[00:20:01]Number two, steric hinges. Number three, hydrogens.

[00:20:30]So just in case just in case you're being asked I doubt they will not even if they want to ask you they will not ask you this way right some free radicals can be stabilized can be stable due to the following stabiliz any how you want to put it due to the following the localization of the un electron now you guys are in 300 level so you have we have done lot of the localization anytime you hear the localization it simply means that there is a conjugated system right a conjugated system in a case whereby you have a double bond so let's see if I have something like this if I have a radical being separated from a double bond by a single bond this is a conjugated system so this electron can come here right this guy come here and this guy come here we move the electron to the next guy so this become you put a dot Okay, because you're breaking this bond.

[00:21:34]This guy comes here.

[00:21:37]Now this guy you now take one and take one and form a bond here. So remember once something once this this is resonance once there is a possibility of a conjugated system right there's bound to be a resonance and for a resonance system a compound that has resonance tends to be more stable. So basically just in case you're being asked how can um free radical be stabilized or what are the factors that can stabilize free radicals you can see the localization of the unpaired electrons right now this steric hindrance is simply having a large you know some having a bulky substance or compound around the electrons to avoid it to react. Imagine I have something like this.

[00:22:32]I have something like this, right? This H when you split this hydrogen is going to cover the back of this. So you can have something like H H.

[00:22:59]So if you notice this guy is blocking this guy. So just in case you're being asked what are the ways that a free radical can be stabilized the localization of the unpaired electrons steric hindrance and lack of beta hydrogens. So please if you have any question I'll be in the comment to take your question.

[00:24:24]All right. Please any question?

[00:24:47]Please, if you have any question, drop it on the chat. Then if you want me to reexlain again, I will. I just want to take some few minutes to explain this then we jump into past questions. That's basically what I want to do.

[00:25:36]Any question please.

[00:25:50]All right. So I presume that since there is no question let's let's continue.

[00:26:08]Now if you can remember in your chem132, if you can remember in your chem132 when we talked about um bond breaking, we said there are two ways a bond can be broken. You can break a bond either through homolytic or hetrolytic.

[00:26:35]So let's see if I have this.

[00:26:38]Anytime you're dealing with radicals, you use a onehead arrow.

[00:26:43]So if I break this bone, this is homolytic cleavage.

[00:26:55]You're breaking the bond such that each atom retains one electron each. This becomes C dot plus C dot.

[00:27:13]All right. So that is homoysis you know a type of bond breaking where each electron of the bond is retained by the atom.

[00:27:26]So let's look at formation or generation of free radicals.

[00:27:42]Generation of free radicals.

[00:28:45]Okay, before then no before then let's talk about um classifications of radical have the first one primary. Sorry.

[00:29:25]Now just like we have in carocation a primary radicals are those type of radicals in which the carbon bearing the electron is attached to just one other carbon.

[00:29:40]Primary radicals are those ones in which the carbon bearing the the carbon this the one bearing this dot is attached to just one carbon. Now for secondary the carbon bearing the dot is attached to two carbon this and this.

[00:30:13]for tertiary.

[00:30:26]Now this is attached to three carbons.

[00:30:29]This carbon bearing the dot is attached to three. For secondary, this one bearing the dot is attached to two. And for primary, any question, please.

[00:31:28]All right. So let's proceed now. Let's look at last year to see if there's any question that we can solve.

[00:31:52]Somebody said let me learn this in sharp sharp no time.

[00:31:58]Yeah, we we on it.

[00:32:26]So let's press proceed.

[00:33:13]So these are the three ways.

[00:33:15]we can actually generate or form radicals. So we call it radicals formation or generation.

[00:33:23]We call this radical formation or generation. Okay. So we're going to look at this photosis. Now please take note of this that lis means breaking.

[00:33:38]Right? Now photosis means light. Photo Photo means light like um quantum of light energy. Photosis is breaking of bond using light. Themolysis theo means heat. So this is breaking of bone using heat. Redux reaction breaking of bond involving transfer of electrons.

[00:34:06]Okay. So now let's take them one after the other. Please. Um, I need past questions. Like I said, I was using somebody's past question in class, but I did not get the soft copy. I was using the person's phone. If you're listening to this, please can you send the past question to my WhatsApp, the one that contains radicals, please, maybe one or two years, the one that contains radical. Okay, I need this so we can use it to solve problems.

[00:34:38]Now let's talk about photosis. Now photosis is a breaking of bond using light.

[00:34:46]Right? No time thermolysis is a breaking of bond using um heat. Redux reaction is a breaking of bond using this um transfer of electrons.

[00:34:58]Okay. Now but they they don't really ask question based on that. They hardly question based on that. So mostly the questions are normally asked based on the types of reaction.

[00:35:09]I'll ask again anybody here can you actually share me a copy of the past questions please let me use it and answer these questions.

[00:36:47]Let's start with photosis. Now what's photosis?

[00:36:54]Photosis is a breaking of bond using light. For example, breaking of bond Not just light, UV light, which is same thing as electromagnetic light. So if I have something like this, um maybe you've seen something like this before, UV.

[00:37:24]You've seen something like this before, UV. Then you see this plus you see this.

[00:37:30]Now this is a full reaction. This is showing us that when chlorine molecule reacts or is subjected to ultraviolet light we have two units or two um radicals. Okay. Now the mechanism of this reaction is this this breaks here.

[00:37:48]This breaks here. Remember M365 is about mechanism arrow. When you're breaking a bond to form a radical the bond has to have one head right it has one head. So this becomes this plus this becomes this. Now this is photosis because you're using UV light. UV is ultraviolet.

[00:38:10]UV is ultraviolet light. Your sunlight somehow is UV light as well. Okay.

[00:38:45]Any question, please? Any question?

[00:39:06]All right, Mitchell. Thank you.

[00:39:13]Now let's quickly talk about thermolysis.

[00:39:17]Now in case you been asked in exam what is photosis? Photosis is a breaking of a bond using light. Now what of thermolysis? As the name implies thermolysis. Theo means heat.

[00:39:29]Now thermmo means heat.

[00:39:33]This is brains breaking. So this is breaking of bond using heat rather for example let's say We have something like this and you hit this then you see one.

[00:40:19]Now this is bas this is the reaction right? This is only showing us that oh when I heated this bond I broke it to this. Whenever they say mechanism, if your mechanism does not have arrow, you're just joking. Mechanism is actually the route, the step-by-step procedure in which a reaction follows, right?

[00:40:45]So, mechnism there is an arrow here. Do you understand? So, that is basically how it looks like. Now, what of redux reaction?

[00:40:55]I'll leave out that guy. I'll leave out Redux reaction. Okay, because the hardly let me get past question so that we can solve So we have a question here. This is last year exam question where they said arrange the following in order of increasing stability and explain your reasons.

[00:44:07]Now, how do we go about this?

[00:44:13]We're talking about stability. Remember we said, okay, please, please write down this write down this question very fast except you have the question. So, I can just solve it at once.

[00:44:33]Now, first thing first, I was supposed to give us something.

[00:44:39]First thing first, this is what we call what we call benzilic.

[00:44:51]Benzilic radical is what we call alilic radicals.

[00:45:04]is what we call tertiary is what we call secondary and what we call primary.

[00:45:12]Now benzilic. How does benzilic looks like?

[00:45:30]This is benzilic which is this guy.

[00:45:37]This guy you're seeing here is benzilic.

[00:45:39]This ring is C5 C6H5. Then this CH2.

[00:45:44]Now this next guy, this one is alic.

[00:45:50]This one is alic.

[00:45:59]All right. We call this guy alic.

[00:46:06]Now after this I'm going to please pay attention. After this I'm going to arrange this for you so that you can see how it works.

[00:46:24]Now so this is benzilic.

[00:46:30]This guy is benzilic.

[00:46:33]This guy is alic. Now let's look at this guy. This guy is tiary.

[00:46:38]Tertiary tertiary radicals are those ones in which the carbon bearing the lone pair or the or the electron is attached to three other carbons. So this guy is CH3 CH3 this stationary because you can see that You can see that we have three CH3 one 1 2 3 and then you have this CH.

[00:47:16]Sorry, this H is not supposed to be here. I think that is a mistake from the past question.

[00:47:28]So this is um this is stationary.

[00:47:32]Now this guy is secondary.

[00:47:38]This guy is secondary. This guy you're seeing secondary. How did I say secondary? Because it looks like CH3 CH3 CH.

[00:47:53]Now in summary class in summary of what I'm saying here now this is the order of free radicals. Let let me give us the order so that the order is that benzilic because this guy remember earlier I told us that one of the one of the factors that can actually make a radical to be stable is the localization of electrons. Okay. Now for electron to be deoized there has to be a conjugation. This question they asked us to explain why because the reason the why is much more important.

[00:48:27]Okay. Now this there is a system here.

[00:48:32]A double bond being separated from a radical by a single bond. So it simply means that this benzilic radicals and structure because if these guys should come here this can actually resonate.

[00:48:44]Benzene has lot of conjugated system. So the most stable amongst all of them the number one the first the most stable is ben benzilic. Why? Because benzilic right has more resonance than all of them. After benzilic is alic can has conjugated system and can undergo resonance. But then this guy will have more resonance structure than alic. So the correct order of this guy will be since they said in increasing order right they said increasing order.

[00:49:22]Increasing simply means let me write it out. Increasing order means from smallest from least stable to more stable.

[00:49:50]Right? So material listen material radical is always a listable less than primary please this is one is primary less than secondary less than tertiary less than alilic less than benzilic benzilic is the highest amongst all of them.

[00:50:18]Okay. Now remember I said primary radicals are radicals in which the carbon bearing the dot is attached to just one carbon. So if you come back here and look at this guy let me keep this guy.

[00:50:46]Now this is primary. This is material.

[00:50:50]So I'll say material radical is this CH3.

[00:51:03]Now this guy is primary. Why do we say primary? because this guy is attached to just one carbon.

[00:51:21]Okay. Now the next one is CH. This guy is secondary.

[00:51:34]Now this is secondary.

[00:51:38]This is primary. Sorry, this is material. This primary. So we have CH3.

[00:51:46]Let me clean this entire board. And I want to show this in very very well.

[00:51:51]Very very well. So let's reduce this screen small.

[00:52:00]So make sure you now primary I'll kill Is that secondary? I'll kill is this guy which can be written as Why do we call it secondary?

[00:52:59]Because the carbon bearing this radical is attached to one two. Why do we call this guy primary? Being this is attached to one. Methyl is not methyl is just one carbon. Now tary is CH3 C.

[00:53:20]Now why do we call it tary? Because this guy is attached to three carbon.

[00:53:33]One, two and three.

[00:53:39]Okay. Now what is the order? This is the order.

[00:53:45]Material increases increasing order.

[00:53:52]Material is less is the most less stable. Now after m is primary after primary is secondary. After secondary is this after this is alic after is benzilic. I already explained what alilic is. Alic is basically a primary carocation.

[00:54:10]But then the carbon bearing the dot is attached to a double bonded carbon which is what we have here.

[00:54:18]This guy is the one bearing the dot is attached to this carbon that has a double bond. While this guy is benzilic already gave us a structure of benzilic.

[00:54:28]All right. A benzene ring that is attached to a carbon with a lone pair or a dot electron. So the correct answer to that question is this. Now what is the reason right they said why now benzilic is the most stable because it has because of electron deoization which will result two which will result to many resonance structure.

[00:55:31]Is any question Any question are we following please?

[00:55:42]Any question are we following? I want to read another question.

[00:57:08]Any question?

[00:57:29]Are you guys Are you guys in this class at all? Hello, I didn't hear me at all. All right. So I said this is a correct order. All right.

[00:58:05]This is the reason is because benzilic is the most stable because elect because of electron deoization which will result in this guy having many resonance structure. Okay, that is the answer to that question. So let's look at another question on that free radicals.

[01:00:59]All right. If you look at we have 3 A.

[01:01:02]We have solved 3 A. 3B is elimination.

[01:01:09]4 A.

[01:01:12]Now this is radical.

[01:01:22]You can see how how technical these people are setting this question.

[01:01:27]They they mixing elimination, reaction and radical such that remember each section says answer one question from each section. So what they are trying to do is that if you choose the particular question let's say for example if you say you want to answer question number three 3 A is radical 3B is elimination some persons will say oh since this guy is radical since 3 A is radical 3 B will automatically be radical but no you are trying to use your head so if you look at that question very well question 3 A is under radical question 3B is under elimination reaction action.

[01:02:09]Now question 4 A is under elimination.

[01:02:12]Question 4 B is under radicals. So we have done 3 A which is arranging those guys in order of increasing um stability. Now let's look at 4 B right which is radicals. So I want to I'll write the equation on the board and we are going to calculate head on right.

[01:05:34]Let's copy this question so I can go back to answer that question.

[01:06:06]So let's sol the first question. They say solution.

[01:06:11]How does stability of a radical affect it formation?

[01:06:16]Please before you answer that question.

[01:06:17]Eh, let's put it this way.

[01:06:22]If you have money, you're very stable. Is it not? So, now will that make you happy? Like, will you be happy?

[01:06:39]Obviously, yes.

[01:06:41]If you do not have money, you're unstable. You will not be happy. So if a radical is very stable, it is very easy to form because less energy will be used. So if somebody should ask you how does the stability of a radical affect it formation? Uh-uh. You why you ask me this kind of question? We all know that if something is not stable, you cannot form that compound because if you form it, how will it how will it actually survive?

[01:07:10]Imagine bringing out fish from the river and putting the fish right on the ground outside the river.

[01:07:18]The fish will die because the fish is not stable.

[01:07:22]So if you put fish where fish is st I'm just I'm just trying to make it you know trying to give you guys illustration so that don't just grab it based on chemistry. So probably the chemistry knowledge you know is kind of difficult for you to remember. You could just quickly remember what I said about stability. If you're very stable in life, right, it's very easy for you to be happy. If you're not very stable, when when a financial otherwise small thing going to affect you. So it's very simple.

[01:07:53]How the more stable a radical is, the easier formation.

[01:08:26]This is because highly stable radicals requires less energy.

[01:08:52]to form.

[01:08:54]So that question that they ask us how does stability of a radical affect its formation is very obvious because if something is not if something is stable right it's possible for you to form that guy if they say come to university ofot if you don't have money to afford your school fees and everything right you actually not want to come to uniot because you know that you will not be stable in uniot but if you have money it's very easy for you to actually come to uni import just like marriage if you have money to marry become very easy right but if you don't have money yes you might still get to marry and by God's grace God will bless you guys but then you like you actually reluctantly not want to because you know that you're not stable financially so that's just basically how it looks like okay please any question let's jump into question number Victor, I've answered your question now.

[01:11:24]So let's look at point number two.

[01:11:27]Discuss.

[01:11:30]When they say discuss, you have to talk extensively, exhaustively what you know about that stuff. Discourse is different from list.

[01:11:47]The mistake lecturers used to do whenever they if you mistakenly say I should discuss it is over for you.

[01:11:55]If you ask me to discuss chief you go tire.

[01:12:00]So you say discuss the factors that affect stability of radicals with one specific radicals. example.

[01:12:13]If you could remember when when I started this class, I told us that radicals are very unstable.

[01:12:21]However, their stability can arise due to the following and I listed out three factors.

[01:12:29]I said the first one is the localization of unpaired electron.

[01:12:45]Let's talk about the first one.

[01:15:46]I just wanted to show us this guy because he said give specific example.

[01:15:50]So I want to start discussing this guy.

[01:15:52]So now you've seen what alilic means.

[01:15:55]Now benzilic is something like this.

[01:16:06]This is benzilic. All right. So you have this.

[01:16:12]You have this.

[01:16:14]So benzilic and alic can undergo deoization because they have conjugated system.

[01:16:23]Now since I've told us or I've explained that let me now give us the reason or exams point that you can tell your lecturers and get your mark for the first What?

[01:18:31]So for the localization of the unpad electron is very very obvious. Now a radical is more stable when the unpaired electrons can be spread across several atoms which will lead to resonance. Right? So take note of that which will lead to resonance.

[01:18:58]Now remember they asked us to discuss to discuss.

[01:19:03]You can now come here and give them example because they asked for example as well. So you can say this is CH.

[01:19:14]Now this is a loan pair.

[01:19:17]This guy will come here.

[01:19:21]You break this bone.

[01:19:24]You now have this.

[01:19:43]That's that for that guy.

[01:19:45]So if I want to write remember they say factor so I've discussed this first factor all right so what we have now is steric and this so right first so I can actually discuss this All right. Um, alilic is stable because of resonance. Just like what I'm doing I just did here.

[01:21:09]Alic is stable because of resonance.

[01:21:12]Miel sir, what if we answer the question using the step you gave us in some free radicals due to the following localization of unpaid elections.

[01:21:30]So Muriel, I don't really understand your question. If you could, you know, hope you don't mind. I would appreciate if you could just take the question again.

[01:21:41]Can you take the question again?

[01:21:44]Can just type it so I can take it again.

[01:22:33]Please can you can you see hear me? Can you hear me?

[01:24:27]Let's talk about sting in John's class.

[01:26:09]All right.

[01:26:38]So just in case you're being asked um free radicals can be stabilized due to steric crowding. All right. Now, steric hindrance for example, let me give you you guys an example.

[01:26:50]We have this guy. This is phen Now on this pH note the pH is finile that this.

[01:27:58]So imagine having this surrounding this guy. This free radical has no choice.

[01:28:05]Right? Now there is resonance inside and there is benzene ring surrounding this guy. So you notice that it will be very difficult for external bodies or other reactant to react to it. Okay, it will be very very difficult. So steric hindrance can somehow increase the lifespan of a radical. Anything that can make a radical to stay you know longer you know its lifetime makes it very stable. So when you actually block something else from attacking the reactive part right it makes it very difficult for that guy to actually go into extinction. So that is number two reason. So I could say I can I can also say um hyper conjugation as well. Right? So let's say number three I will ignore the instead of saying the beta hydrogen I'll say number three.

[01:29:12]I configuration.

[01:30:06]So for the next one is hyper conjugation. The more the hyper conjugable hydrogen the more stable the radical will be.

[01:30:18]That is why tertiary alle is more stable than secondary is more stable than primary.

[01:30:37]All right. So please if you have any question ask now to make it very easy for you guys I will snap a page of my material and send to the group so you can just revise. All right let me allow you to use the rest of the night to continue with your solving.

[01:30:59]I wish you guys the very best. Um I was I was in school today to teach you guys but unfortunately you guys did not show up. From what I learned the exam did not go very well and I'm deeply very sorry that honestly there is I I thought I I wish I I was able to help right pure chemistry was not my field like I didn't do pure chemistry in school. Yes I can teach it but it's really going to stress me out. the person that used to teach it for me went for NYC. So I'm seriously so sorry about it. But what I've taught us you know this marathon class for those person that have attended plus the videos I sent and asked your call share to send for you guys plus today's class right I'm sure you should you can actually get some mark right from all the angles like not just some mark you should be able to get enough mark to give you an A or a B please any No, there is sound actually just that my I'm using my phone as microphone.

[01:33:11]So most times if I'm if I'm if I'm writing my screen will just go off. But if I'm talking, it will be on. But if I stop talking for a long time, my screen light once my screen light ups, the microphone will seize. I need to tap the screen for the light to come up before the microphone can come up.

[01:33:34]So that's why sometimes if I'm writing, it's as if you're not hearing my voice.

[01:33:38]Once I'm done writing, I'll just tap on the screen again.

[01:33:56]Please. Um, can I get Okay, somebody sent me a past question. I think that should be Muriel. for you.

[01:36:10]today I've taken lights.

[01:36:19]So please if you have any question ask before I'll go off today I just wanted to do radicals today and I just checked your past questions um they've not really they did not do much on radicals for you guys. So even if they want to ask questions on radicals it will just be um not much but extensively I've done substitution reaction and elimination reaction extensively I took my time for two days to break down those two topics.

[01:36:44]So I'm very certain that for those person that attended the class if you come across substitution or elimination should be able to substitute the hell out of it. All right. So for this um radicals this is just 70% of what I gave to us. But from the best of my knowledge I just got a message now that we were not taught but regardless of that I know how chemistry can behave. You can still bring it because it's in your text. So with this now you can just go back to if you understand this very well can just focus on rearrangement for tonight. So I wish us the very best and have a wonderful night rest. If you have any question please my DM is open. All right. This my phone number for those persons that do not have access to my contact. So this is my phone number.

[01:37:32]Don't worry just any question you have just text me. I'll be much delighted to answer your question. I'll be so happy to answer your question. Right. So this is my phone number 070 38 1 0 1 576 Delta of All right. So that is my name.

[01:38:04]That's my number.

[01:38:15]So, if you want to join the group chat, send me a message to join the group chat. So, I'll see you tomorrow or good night.