IGCSE Chemistry LIVE Lesson - Ch.11 - Organic Chemistry (Polymers)

Hinzugefügt: 2026-05-15

[00:00:03]All right, we have a lot of questions to get done. So, let's see how I can go through them and then I'll give you to try.

[00:00:09]Right.

[00:00:31]Um let's quickly finish on polymerization and then we do the questions. We should do a lot of questions then I can give you on that. Um and I'll see if I can do isism with you guys. Uh Yep.

[00:01:17]What happened? I didn't Wow.

[00:01:29]Um, why didn't you call me LGK definitely?

[00:01:54]Let me just Okay, let's get to work. Um, I can't see where I've put those notes from yesterday. Let's continue. I'll I'll send them to you guys when I find them.

[00:03:41]Right, let's continue with what we were talking about polymers when we were talking about polymers.

[00:03:47]Um, I'll just remind you um and then get to the last parts and then we do a lot of questions. I I want to focus more on questions today. So I I kind of know you have an idea of what we talked about. So I will not repeat myself too much. Okay.

[00:04:04]Are we together?

[00:04:06]Um, we got to the the fourth part, I think, when we're talking about deducing the mona. So, let me let me re let me explain to people. I'm not going to rewrite the notes. Um, um, I'm just I'm just going to share them with you, but let me explain to people what I had talked about yesterday real quick and then we can quickly get to the stuff for today. Are you ready? Yesterday I said that polymerization okay for you to understand polymerization th this is a fact polymerization this topic has eight parts okay one definition of monomer and polymer two addition polymerization.

[00:05:21]Three, how to draw repeat units.

[00:05:28]Are you seeing the parts that you must know? How to draw repeat units which we talked about yesterday for how to find a monomer.

[00:05:42]We didn't do this from a polymer.

[00:05:47]LGK, can you see this?

[00:05:50]Five, condensation, polymerization.

[00:06:10]Six nylon polyesters, Peter, PT, proteins, Plastics and environmental problems.

[00:07:20]right? Are you see right?

[00:07:31]Let me put let me make sure you know the hard things.

[00:07:35]Um, addition polymerization, we talked about it yesterday. We said it's from alkenes. The repeat unit, we said you remove the double bond, right? Make sure I I gave you the parts here. We want to talk more about monomer, condensation, polymerization, nylon, and polyester, and plastics, and then uh recycling, and we'd be done. So, I'm going to be moving a little bit fast. Are you ready for that?

[00:08:01]Can I start?

[00:08:05]These are the parts that we need to do.

[00:08:06]Then we get to questions. Are you ready to learn? Is your mind ready? Is your mind rested? Are you ready, Seth?

[00:08:20]Seth, can you hear me?

[00:08:33]Remember, let me start from um repeat units and go down.

[00:08:40]Let's let's start with it.

[00:08:44]Can everybody hear me? Majita, can you hear me?

[00:08:51]Okay, good. Tapello, can you hear me?

[00:08:57]Okay, good.

[00:08:59]That's good. I was just making sure you can all hear me. I'll check the register at the end. Let's uh let's get to work.

[00:09:05]So, here we said um I needed you to know.

[00:09:26]I need to do Right, let's quickly do it. I'm starting from three, moving as fast as I can and we'll be done. Concentrate, guys. I'm just going to remind you, okay? Um, about a repeat unit. We said, we said a repeat unit is the small section of a polymer that repeats many times.

[00:10:34]And we saw I showed you how to construct it. I said to draw it, you draw it from a monomer. Okay?

[00:10:43]Because we're going to do questions on that. So that's why I want to repeat it real quick and then we do the questions.

[00:10:48]We got to do we have to do questions. So everybody let's go to draw a repeat unit. I said everybody to draw a repeat unit from Right.

[00:11:15]Let's go to here. One change the carbon to carbon double bond.

[00:11:36]into a single bond. Then two add continuation bonds on both sides. Okay, I should say on both sides. Then three um what you must also do is to place brackets.

[00:12:00]Okay. Then around the structure and then the last thing you should do is place an N. So I can say it in any way.

[00:12:12]Add a small N outside the brackets.

[00:12:21]And here is one we said you have 18 which can be written like this. Let me teach you another way you can find it.

[00:12:31]Okay, this is the same as doing it like this students. Carbon then you put H.

[00:12:41]You should understand how this works.

[00:12:42]Then you have your double bond with carbon. Then the hydrogen's are like this.

[00:12:47]this when you make it into a polymer.

[00:12:51]You won't have to draw the whole thing.

[00:12:53]You have to just show the repeat unit.

[00:12:55]They'll ask you about it. Remember single bond here. So carbon to carbon is now a single bond. Then put continuation bonds outside. Then these bonds here, these two hydrogen bonds will now be up and down like this.

[00:13:11]Will now be up and down like this.

[00:13:25]Let's go. This is how it is. You put an end. This is a repeat unit.

[00:13:33]If we were to do it like this, right? This is this is called ethine and the polymer it forms here from the repeat unit is poly ethine.

[00:14:13]So when you read a repeat unit you it's like it's the polymer itself only that it's a section of the polymer but it's the very same thing. So please the repeat unit will be the polymer itself.

[00:14:24]Okay. Now let's do the fourth thing and let's finish it. Deducing the monomer.

[00:14:35]Deducing the monomer.

[00:14:38]Okay.

[00:14:40]From the polymer.

[00:14:43]Deducing the monomer from the polymer.

[00:14:48]Deducing the monomer from the polymer.

[00:14:50]Write this down please.

[00:14:52]Then here are the steps to reduce a monomer from an addition from addition polymer to to deduce a monomer from an addition polymer. Number one, first identify the repeat unit. So you get a a polymer.

[00:15:28]If you want if you asked to show the monomer, find what's repeating. Find the small section of the polymer that keeps repeating. That's the repeat unit. Find it. Then when you find it, you write it down. Then you remove the continuation bonds.

[00:15:49]remove the continuation bonds.

[00:15:53]Then three, change the single bond between the carbons or the carbon atoms into a double bond.

[00:16:17]LGK, can you see this?

[00:16:21]Can you see this?

[00:16:26]You get a polymer.

[00:16:29]You get a polymer.

[00:16:34]Whatever. If it keeps going, let's just say you now get the repeat unit. Okay, if you now have the repeat unit, then now that you have the repeated, you find you you see the big chain, you find the repeat unit, once you have it, you change this single bond into a double bond. So it will be like this.

[00:16:54]Then you remove the continuation bonds and you remove N. Remove the continuation bonds maybe let me say N and small N.

[00:17:08]Are we together?

[00:17:13]Are we together?

[00:17:20]So this will be the alken monomer.

[00:17:28]Okay.

[00:17:32]Don't remove side groups.

[00:17:36]Don't change positions of atoms.

[00:17:39]Don't leave these bonds being single.

[00:17:42]It's a common mistake.

[00:17:44]Make sure you change it back to a double bond. Listen, you have to hear it because it's a common mistake. Make sure this single bond that was in the repeat unit. Hey, the biggest problem I know from students is that they want to change from repeat unit in the polymer to a monomer without changing the without putting the double bond back.

[00:18:14]The monomer has a double bond.

[00:18:18]The repeat unit does not, but the monomer does.

[00:18:23]So when you change back, please, I beg you, put back the double bond. And this N, you're going to put it here at the back in front. Say N molecules of this.

[00:18:39]I'm sure you know about it already.

[00:18:41]Hopefully, I've made you know.

[00:18:44]Are we together?

[00:18:52]Please remember to bring back the double bond. I'm begging. I don't want to see wrong things. Five. Let's talk about condensation polymerization. I don't have time. Let me move.

[00:19:17]Yes. Are we together?

[00:19:25]Right, let's go.

[00:19:29]Condensation polymerization occurs when monomers join together.

[00:19:57]condensation, polymerization occurs when monomers join together and it's the same thing as addition basically, but here is the last with the removal. That's the only difference.

[00:20:13]Listen, with the removal of a small molecule.

[00:20:20]That's how it happens. There's the removal of a small molecule. And this is water. Okay? usually water almost all the time. For us, it's always water. So, we don't worry about it. So, basically, we no longer have a double bond. In our kins, we had the double bond splitting up in here. They make space for the things to join by removing guys. So, it's a very unfair way of of making polymers. Very, very unfair. Are we together?

[00:20:54]Hello.

[00:21:01]Okay.

[00:21:06]The monomers contain the following functional groups.

[00:21:19]I'm helping you to see the monomers that we are going to do here.

[00:21:24]It's going to be one caroxilic acids, two armines, and three alcohols.

[00:21:36]Okay? And we're going to have them do condensation polymerization. And when they do condensation polymerization, we get a water molecule as our byproduct.

[00:21:48]What is going to be removed is a water molecule. Okay?

[00:21:53]So let's do it. Examples to know. Let's put the examples to know.

[00:22:04]Nylon PT proteins.

[00:22:14]Are we together?

[00:22:18]Hello. Are we together? Right now let's start with nylon that is the number six.

[00:22:36]Let's talk about nylon which is part of condensation polymerization and let's see what we can know from it. Nylon and say this is a poly amide.

[00:22:54]We start with nylon which is a poly.

[00:23:02]Okay. So nylon is a poly amide and I'm going to make you know what it is what that means but just right here to say made from one dicaroxilic acid and two diamine.

[00:23:32]What happened there? Honestly, sorry for that. I want to show you the diagram real quick. Let me share my screen again.

[00:23:44]Let me share my screen again real quick.

[00:23:47]We have work to finish here.

[00:23:50]We're starting with nylon and we do questions. Come on, let's move. Nylon is a polyamite. So, let me explain to you because you're going to meet this those who continue with sciences. you're going to meet something which you call an amide.

[00:24:03]Right? When we say it is made from a dicabarilic acid, let me write it like this.

[00:24:12]Di caroxilic acid contains two carelic acid groups.

[00:24:30]Okay, it contains two caroxilic acid.

[00:24:33]Dicaroxilic acid just means it's a caroxilic acid on both sides.

[00:24:39]Okay.

[00:24:42]A diine contains two amine groups. Let me explain. Right. So nylon is going to have something like this. There's going to be nitrogen.

[00:25:02]There's going to be carbon bonded to double bond all like this. This is what we call an amide linkage. Are we together students? Are we together?

[00:25:15]What they call an amine is nitrogen bonded to carbon. But this nitrogen is not bonded to a carbon with oxygens.

[00:25:34]It's bonded to carbons that have hydrogens or something. This This is an amine.

[00:25:40]Are we together?

[00:25:43]This is an example of an amine. It cannot be bonded to a carbon that has oxygens.

[00:25:52]So there are two situations that you meet. Are you listening to me students? There are two situations you meet. One is you have your nitrogen bonded to only a carbon with hydrogens.

[00:26:07]That's where it starts. That's an amide.

[00:26:09]That's a simple situation. Then when we get to a crazy situation, which doesn't always happen, what we call an amide, which will only happen when we are forming nylon, it is when the nitrogen is bonded to a carbon with oxygen. Are we together? So we should quickly draw that. Are we together?

[00:26:37]So we say it like this.

[00:26:41]Let's form the amite so that people can see carbon double bond with oxygen. The Oh, so the nitrogen is right next to a carbon which has oxygen. Yes. So if the nitrogen is connected to a carbon with oxygen with a double bond and oxygen, that's an amite. Yes, that's always an amite. Yes. And that's the that's an easy way to see nylon. Yes, the amide will be repeated. Yes.

[00:27:08]So you form let's just make two things.

[00:27:11]You're going to have C2H4. I don't care what we have here. But this side we have your caric acid. Okay, which is CO. If you want, you can say CO H. Okay, I'm not I'm not I don't have a problem with that. No. Then this other side, you still have the same thing. your C O H.

[00:27:36]Okay. So, it is you do it.

[00:27:40]So, C2H4 like this.

[00:28:22]Are you seeing this?

[00:28:26]So they come together students we don't care what happens but when nylon is being formed we have something with a car this is a carelic acid couble bond O and it has it again on the other side what sir what is that this is a darelic acid and when you name it you look at this how many carbons does it have in total one then these are two it makes them three then this is four So you say butane then you say diic then you say acid because it's a dicaroxilic acids.

[00:29:10]Then we have a diamine which we say you need to tell us what are the positions tell us what are the positions of the nitrogens.

[00:29:23]One nitrogen is on the very first carbon. The other one is on the second carbon because there are two carbons here. So it is how many carbons do we have first? Two. So it is ethane. Then how many nitrogens do we have? Two. What are their positions? Cuz it's a damite.

[00:29:39]It'll be on position. If there were three carbons here, then it would be on position one and three or what? Here it is ethane one two. Then you say die ammon.

[00:30:02]Okay.

[00:30:25]Condensation polymerization right. Are you see are you seeing this students?

[00:30:55]Students are you seeing?

[00:30:59]Hello.

[00:31:01]Right. This is what it would be like these two and you just form. Now let me say something right away which we're going which which you're going to need to know. This dicarbosic acid is going to keep coming. This dicaroxilic acid is going to come for the second thing which is called PET. So you have to know PET and you have to know nylon right when we say PET it's a shortcut okay the bigger name I'll tell you but the dicabilic acid is there for both of them and here it is meeting a diamine on the other side it will be meeting a dio because I told you that the only thing you expect to meet is something with caroxilic acids on both sides amines on both sides and alcohols on both sides.

[00:31:53]This guy will be there in both. This guy will be there in nylon only. He will be there in PET only. What you must know is that we need to make space to make these things start to join together.

[00:32:10]So he's going to sacrifice O.

[00:32:13]This one will sacrifice H. and also this one and also this one cuz they have to sacrifice on both sides to join from both sides and make a continuous chain.

[00:32:24]At the end of the day, you're going to have this O. So, the caroxyic acid always sacrifices an O, sir. Yes.

[00:32:35]Then the other guys, whether it's the diamide or the dial, which means the two alcohols, they always sacrifice just an H. Yes.

[00:32:45]Okay. So, in terms of sacrificing and what I'm going to get, I understand that now, sir. Thank you so much.

[00:32:52]Okay. You understand it? Yes. Thank you.

[00:32:56]Now, I need to know how to then form how to then draw the polymer. Now, remember, when you're doing the polymer, all you need to put is the repeat unit. You need to put the repeat unit. So, we're going to need to see you put an N. We need to see it.

[00:33:14]That is why I repeated myself on repeat units.

[00:33:20]What you're going to do? What am I going to do? You take this thing.

[00:33:26]Let's just put it the carbon. This carbon is there, right? With this double bond O.

[00:33:42]Then you do it like this.

[00:33:45]Here it is. Now we have gotten open here. Open here.

[00:33:53]Okay. This bond is now open. And here it's now open. We've made space. We've removed these two will join and go and form a water.

[00:34:05]So will this one and this one.

[00:34:09]Then what remains is this nitrogen coming to join in and this nitrogen has this hydrogen. So it has that hydrogen and its own C2H4 or whatever and nitrogen and the hydrogen.

[00:34:25]There we go. So this is the polymer.

[00:34:29]This is the repeat unit which will keep repeating I don't know whatever how many times and you can put your water molecule. Okay? Even two of them get This here is why this we say is a polymer made of amide bonds.

[00:34:48]A carbon with a double bond will at some point meet a nitrogen with its hydrogen.

[00:34:53]That's an amide.

[00:34:56]This is the arm link.

[00:35:00]You're going to meet it. You are going to study amides at A level and at university.

[00:35:08]you study amides deeper. This is an amide link.

[00:35:14]Anyway, let's move on.

[00:35:16]Um, now the second thing that people should know is how to then use boxes.

[00:35:20]Okay, how to use boxes. So, when you're using boxes to represent, you just say, okay, let's say I have this. It is this.

[00:35:30]Okay, can you see it? Then this one will be represented by a shaded box. If you want a shaded box to represent the guy that was inside your dicaraposelic acid, don't let me down.

[00:35:44]The guy that was inside your dicapelic acid is this one. We don't want to know what he is. If he has 10 carbons and whatever hydrogen's, we don't care.

[00:35:55]Okay? 10 carbons, 20 hydrogens's, we don't care. 11 carbons, 22 hydrogen's, we don't care. What we know is he's there which we don't care about but we know that on one end and on the other end he has caroxyic acids. So we put those he has carelic acids.

[00:36:21]Then what we know is the person he's joining to has amine and amine on both sides.

[00:36:36]So there's another box which happens not to be shaded this time to show it's for the other guy.

[00:36:45]He will have students you show him. He will have nitrogen both sides and it's like this. It joins.

[00:37:01]If you've made your carbons face up there, you make your hydrogen's face down there. Something like this. This is what happens. And we know what it's bonded to.

[00:37:11]This guy shade him.

[00:37:15]Oops.

[00:37:43]Wait.

[00:37:52]It's bonded to this guy as well. What does he have? Carbon double bond or what does he do? He joins in with the nitrogen. And this continues to happen.

[00:38:08]Did you see that simple fixture, right?

[00:38:15]You can you can keep putting. I don't care. If you keep putting then you can put another one. This chain keeps going. We know that. Have you seen that? What is this nylon?

[00:38:42]Are we together?

[00:38:48]Okay.

[00:39:00]The polymer using boxes.

[00:39:10]This is the diagram.

[00:39:12]Should we go to polyesters?

[00:39:15]The second thing now. Are you done with nylon?

[00:39:19]Hello.

[00:39:30]Yes.

[00:39:33]Why is this an a polyamide? Because if you look at it, it has these many arm linkages.

[00:39:45]Carbon double bond O with a nitrogen blah blah blah blah blah. Uh and then now we go to the next thing. Okay, now we go to the next thing and we are now on pet.

[00:40:00]Are you ready?

[00:40:03]Let me write next write seven.

[00:40:11]Right.

[00:40:12]Poly esters and pyester and pet.

[00:40:36]Are you there?

[00:40:40]Pity is a polyester.

[00:40:48]What did we say an a polyamide means?

[00:40:51]Many amides many amide linkages in the bond. Polyester many estester linkages.

[00:40:57]We know what an esta is carbilic acid and alcohol. PG is a polyester formed by condensation polymerization. I need to finish this. Come on. Condensation.

[00:41:13]Polyization.

[00:41:16]I'm almost done. One more thing. Yeah.

[00:41:19]Polymerization. Just a few more things.

[00:41:22]Okay.

[00:41:33]It is made from what?

[00:41:40]a D caroxyelic acid to a dial.

[00:41:54]Are we together?

[00:42:04]PET is used before I show you in plastic bottles and synthetic fibers such as ter.

[00:42:32]Okay students.

[00:42:42]So this is in brackets trade name for P.

[00:42:54]So nylon and tell PT info is actually In short, it's terine when it's in trade. But this is polyethylene.

[00:43:19]Did I do it well?

[00:43:23]Yeah.

[00:43:25]Did I do it?

[00:43:30]Whatever. If it's wrong, it's okay, but it's close. Anyway, terolene is the other thing. So, when you're asked for the two condensation polymers, you might as well say nylon and terolene. It's still fine. We used to call that is when I wrote my IGCS, we used to just say nylon and terine. Let's let's do the the the the guyic acid. Again, don't let me down. Do not let me down. Where's the problem? Tell me where is the problem in knowing that you start with a with something that is a caroxyic acid. Don't you know this is a caroxilic acid when it has this? When something ends with this, don't you know it's a carillic acid? Now, are you seeing that it's caroxyic acid on both side?

[00:44:14]Can't you see that? So, can't you see this is a darillic acid?

[00:44:27]Right.

[00:44:29]We can even change this to put four and eight or say six and four rather.

[00:44:43]This should be like they call this terapalic acid.

[00:44:54]Even if you keep it as C2H4, I don't mind to be honest.

[00:44:59]Then what happens? Ends with an O. It meets this guy. C2 H4 ends with O here. Ends with O here. What is this? We call it a diode.

[00:45:17]So this is ethane.

[00:45:20]Okay? Because it has two carbons. So it's ethane. Then you say one two dash two numbers one two. Then when you're going back to letters you put a dash.

[00:45:29]Then you say dial. Here you can say this is butane diioic acid.

[00:45:41]Then you quickly do we know what happens. This guy always sacrifices his O. If it's the acid, this is an H. Then this O also goes. So does this H go.

[00:45:53]Right? And now we can start to form these polymers. We just put the repeat unit. So let's do the condensation polymerization.

[00:46:03]And let's put the repeat units.

[00:46:07]Condensation polymerization.

[00:46:11]Let's put the repeat units.

[00:46:14]That's the only thing we got to put.

[00:46:16]Then we get to proteins.

[00:46:19]We just put this guy.

[00:46:22]And um here's a double bond O. Okay.

[00:46:26]Carbon with a double bond O. This one.

[00:46:30]And it's open now.

[00:46:47]There we go.

[00:46:51]Oh, there like that.

[00:47:07]Then we put H2.

[00:47:12]Have you seen Right.

[00:47:20]This right here.

[00:47:40]This is a repeat unit of a polyest.

[00:47:47]Now let's put how you represent this.

[00:47:51]You now know how to do it. Let me quickly do it with you. Put the first box. You can shade it or you may not shade it. I don't m I don't care. You know that this one is a double bond O and a double bond O.

[00:48:03]And it is open like that. Now the other box we put the second box which we'll put won't we won't shade it. And we know that instead of a double bond O or an N, it's just an O which will now bond and continue.

[00:48:22]Wow. Really? Yes. Then the next one.

[00:48:27]Okay. The next one shaded connected to a C double bond O which then connects. Then this C D bond O which connects. Then the next one would be empty which is connected to N O which connects which is connected to N O which goes. So you must know what your boxes have. Just like the other one we know it had one had C double bond O this one the other one had an N and an H and we knew it's like that. This is what you'll be having. And that's how you use boxes to draw the structure. Okay.

[00:49:09]using boxes to represent the chains.

[00:49:28]Are we together so far?

[00:49:33]Hello.

[00:49:35]Are we together students right >> now? Should we start with plastics uh or should we start with proteins?

[00:49:49]Can you tell me?

[00:49:58]Let me do it like this. Let me do pros.

[00:50:08]Let's talk about proteins.

[00:50:11]We are We are done, guys. We are done.

[00:50:15]You've done the hard part.

[00:50:17]Okay.

[00:50:21]Write it with me to say proteins are condensation polymers.

[00:50:34]We'll do some question made from amino acid monomers.

[00:50:59]Amino acids contain One, an NH2 group.

[00:51:11]Two, a C group.

[00:51:23]So, make sure just note the very same thing we did with our polyamide.

[00:51:30]We have an amine and we have a caric acid.

[00:51:35]Are you see now? So basically we can say that proteins are polyamides just like nylon. Yes.

[00:51:58]Okay.

[00:52:00]only that they are natural polyamids.

[00:52:11]Are we together?

[00:52:18]Okay.

[00:52:20]They are natural polymers. You can say here why they contain many might mix.

[00:52:35]Okay. And occur in living organisms.

[00:52:51]Are we together students?

[00:52:56]Hello.

[00:53:00]We'll be calling them peptide links and that is how we form a protein. Are we together?

[00:53:14]Right.

[00:53:19]Write it with me today.

[00:53:23]An amino acid contains an NH2 group on one side and a CO2 group.

[00:53:50]on the other side.

[00:53:55]Okay.

[00:53:59]So, let's show one.

[00:54:05]Going to put Let me put There we go.

[00:54:29]Have you seen it?

[00:54:38]Have you seen it students? Are you seeing now the protein?

[00:54:49]Are you seeing now the amino acid which then forms the protein?

[00:54:54]You've seen the one which forms the nylon. You've seen the ones which form the PET or terine. Now you are seeing how we form a protein.

[00:55:06]We have this is an amino acid.

[00:55:12]Amino for amine acid because it has the acid. So it is both at the same time.

[00:55:20]That is why we call it amino acid.

[00:55:26]So amino acid what changes on you for us to get different proteins? It's this part. But we know what we what he has at the end.

[00:55:38]He has a caric acid on one end and an armine on the other end. Have you heard me?

[00:55:55]They come together now.

[00:56:56]Have you seen then?

[00:57:40]Right.

[00:57:50]Let's see.

[00:57:53]Let's see here. Sorry.

[00:58:00]There we go. Let's finish it up. This is the last one. Come on.

[00:58:06]Come on.

[00:58:08]Condensation, polymerization.

[00:58:10]We are here.

[00:58:15]Obviously, you know what you get now.

[00:58:17]You can all see what you get. What will you get? The same thing.

[00:58:23]You put this thing. Then you put this joining to him. So we do that. So you have your nitrogen like that with two hydrogens one to a carbon like this.

[00:58:41]Okay.

[00:58:47]We don't you don't put it like this now.

[00:58:49]You put it like this. Then it connects.

[00:58:52]Okay. It connects with this nitrogen who has made space by selling out one of his friends and snout the nitrogen like that.

[00:59:19]There we go.

[00:59:50]peptide link.

[00:59:53]Are you seeing this now? Let's make it. Let's put it. This is now an interesting one because guess what? When you do the boxes, we actually don't care the order you do.

[01:00:09]But now you don't put the same thing both sides.

[01:00:14]This side we have a nitrogen. Okay, I I made a mistake here. This should be like this. Wait, wait, wait, wait, wait, wait, wait, wait. This is not a repeat unit and it begs for problems. You can put it like that. I mean, if you are making only one uh your protein just like this. But if it keeps repeating then you'd have to put uh this continuing. If I for example now do the boxes I need the nitrogen on one side of course which has an which has a hydrogen and is open. Definitely open and on the other side I will need a carbon with a double bond. Oh here okay I don't care about this is here. I care about the tips the ends.

[01:01:02]That's why that's what you'd be doing with the box. Now basically you join him to this thing again. So but now the nitrogen should face down and the box should be blank and the carbon double bond O should face down as well.

[01:01:17]Then you get to the next one. He is bonded to what? To a box. And what is the end of that? He just don't go to a box. That box should have an end cuz here's an end. The box should have an end. It is a nitrogen with a hydrogen.

[01:01:34]Now you put the hydrogen up which is on the box and ends like this.

[01:01:44]Right now you put a nitrogen going down.

[01:01:48]That box is now empty which is like this.

[01:01:57]Are you see?

[01:02:00]Are you seeing now we talk now we go to plastics because I believe you're done. I believe you can do the boxes with me because you know everything comes from the end of those boxes in pet. One box has C double bond O on both sides. The other one has O on both sides. In nylon, one box has nitrogen with hydrogen on both sides. Then the other one has carbon double bond O on both sides. And they are joining.

[01:02:47]I don't want to see fiction.

[01:02:51]You better put the boxes joining with the ends there.

[01:02:57]For protein, you need to show nitrogen and nitrogen on one side and carbon double bond O on another.

[01:03:08]Then you join it to the other box. You just don't join it to straight to the box. Obviously not.

[01:03:17]You join it to the end of the other box cuz the other box also has an end. He also has something at his hand as it at his end which is now a nitrogen and a carbon double bond or like this which joins to the end of another box. Be careful.

[01:03:55]Are we together?

[01:03:59]Students, don't let me down. Students, don't let me down.

[01:04:07]Thank you. Now, um, let's do the next part. Okay.

[01:04:17]I'm going to write in N.

[01:04:27]Thank you for all this, sir.

[01:04:30]Now, let's do plastics and There is.

[01:04:55]Are you see?

[01:04:57]I see.

[01:05:09]Are you seeing everybody?

[01:05:17]Right.

[01:05:19]Let's quickly write. Just going to quickly write important parts.

[01:05:26]Write this.

[01:05:28]Many plastics are chemically unreactive and nonbiodedable.

[01:05:50]They are not biodegradable.

[01:05:53]What do you mean when you say they don't biodgradable?

[01:05:57]Write in bracket. Okay.

[01:06:01]This means microorganisms, microorganisms cannot break them. Easy.

[01:06:38]As a result, disposal of plastics which are polymers, plastics are polymers causes environmental problems.

[01:07:00]microorganisms, bacteria and all that cannot break down plastics. So their disposal is a big problem.

[01:07:12]Plastics disposed of in landfill sites, take up valuable land. Like we we're actually just done, okay? We are doing a bit of theory that you must also know. But the main ideas are done. We've we've crossed the tees, you know. We've dotted the eyes. You're doing very well. Okay.

[01:07:54]Hello. Are we okay?

[01:07:59]Let me say why we are studying. If you want to know just you can write to say plastics are made from polymers.

[01:08:12]These are just pol.

[01:08:17]Okay.

[01:08:23]Plastics disposed of in length take up valuable land because they do not decompose.

[01:08:38]Because they do not decompose.

[01:08:43]Plastic pollution in oceans harms marine life.

[01:08:59]Plastic pollution in oceans is deadly.

[01:09:03]I'm telling you, it causes some environmental issues there. It harms marine life.

[01:09:13]Okay. What about burning them?

[01:09:17]Incineration or burning of plastics.

[01:09:24]When you burn them, you're going to release carbon dioxide, which contributes, which contributes to climate change.

[01:09:47]which contributes to climate change.

[01:10:16]Give me a sec.

[01:11:05]Give me a second.

[01:11:43]Right. Okay.

[01:11:46]What?

[01:11:49]Yes. Okay. So, so here here are the problems we say. Number one, uh they take up valuable land. Okay. Because they do not decompose. Number two, uh if they're in oceans, it harms marine life.

[01:12:02]Number three, we said it releases carbon dioxide which contributes to global warming or climate change. Okay.

[01:12:12]Uh number four you can say you can say uh some plastics some plastics like PVC can you see all these problems release toxic gases.

[01:12:35]Okay. Eg HCL when burnt okay when burnt or burnt I don't care whatever then last one incomplete combustion are you seeing all the problems caused by plastic by plastic class can produce toxic carbon monoxide time.

[01:13:08]Yes.

[01:13:10]Are we together?

[01:13:25]Right. I'll give you we'll do example questions. Uh we'll do example questions. I don't want to do too many because for the sake of time. Are we together?

[01:13:35]I'll do your example questions. Now let's talk about the very last thing. Um PET repolymerization and recycling.

[01:14:00]Are we together? Write this.

[01:14:05]Just write this. Not too many. I'm just going to give you three, four lines.

[01:14:10]Four lines that I'm doing. And we do questions. You're doing very well. I'm proud of you guys. Let me see if I'm still live.

[01:14:20]Yep. Okay. It's going on well. Wow. Why is the network red now? Why is my styling red? I don't know. Why am I stalling?

[01:14:30]The network is weak for some reason guys. I don't know why but anyway it doesn't matter. Let's keep going.

[01:14:38]Right for me to say pet which is terine is a polyester.

[01:14:45]Yes.

[01:14:47]used in plastic bottles and fibers.

[01:15:04]PET can be de polymerized.

[01:15:16]It can be deolymerized into its original monuments.

[01:15:27]into its original.

[01:15:30]Really? Yes, I can take it back. Yes.

[01:15:34]Okay. Really? Yes. Using enzymes or by using other chemical methods really. Yes.

[01:16:03]The polymers or let's say no the monomers that are reformed can then be repolymerized.

[01:16:18]Wow, this is cool.

[01:16:21]To produce new pet.

[01:16:27]So that's why bottles can be recycled.

[01:16:29]Yes. Terrillene. Yes. Terline can be recycled. Yes.

[01:16:34]And they can make new terin. Yes. Wow.

[01:16:38]So what do they do? They depolymerize.

[01:16:42]And they repolymerize.

[01:16:45]They depolymerize using enzymes and repolymerize into new pet.

[01:16:54]Wow. This saves resources.

[01:17:00]This saves resources.

[01:17:06]and energy and reduces the carbon footprint of PET production reduces the amount of carbon dioxide released.

[01:17:32]Basically, I hope you enjoy. Sorry for this jam.

[01:17:40]It always comes when I'm enjoying myself.

[01:17:46]Okay.

[01:17:56]Right. Let me share my screen.

[01:18:15]Are we together students?

[01:18:21]Hello Okay, now we're done.

[01:18:39]Let's do questions.

[01:18:52]That's two question.

[01:19:02]That's the question.

[01:19:15]May June 2023 first paper say questions polymer questions I'm telling you which papers you then go to okay the papers which you then go to and uh open and you do the questions so first one polymer questions first one May June 2023 paper 42 number six. This the one we are doing numbers question number six. Let's see here.

[01:20:03]Are you seeing the questions students?

[01:20:11]We're only looking at the polymer question. Hello guys, can you hear me?

[01:20:24]Right.

[01:20:26]Give us one repeat unit. How easy is the repeat unit? You take one box. Let's say I take this box for example, right? If I take this box, then I'm going to end at this one. And we know that it's like this this box.

[01:20:45]If he has carbons connected to him, it means the other one has oxygen connected to him. So we move him with his oxygen.

[01:20:53]So it's going to be like this. This is it. So you can circle it or you can do whatever you want. Okay.

[01:21:02]This is a repeat units because they say it's circle one.

[01:21:07]Draw the structure of the monomers which make up PET.

[01:21:13]Draw the structure of the monomers.

[01:21:16]Right? If I want to use the box, it's still fine.

[01:21:22]You can do it like this.

[01:21:26]Then you say O.

[01:21:32]Then you do another one and you shade it and you say C double bond O H C1 O H Okay, I together.

[01:22:04]So easy. Still a type of polymerization um used in making PET. All these are condensation.

[01:22:14]So we saw it's condensation polymerization and we're done.

[01:22:22]Is there a question students? Is there a question here?

[01:22:33]Hello.

[01:22:35]Is there anyone with a question here?

[01:22:38]Let me refresh.

[01:22:48]Huh? Students, is there anyone with a question or you're all good?

[01:22:57]All right. So you see that this one is done. Mazita Mazita, can you hear me?

[01:23:10]Okay, great.

[01:23:13]Let's go to the next one and let's write it down.

[01:23:19]Let's now go to May June 2024.

[01:23:23]This is paper 41. So can you write everybody May June 2024 paper forward.

[01:23:37]Write this. Open this one. May June 2024. Can you all write it?

[01:23:42]Write it. Write it. Write it. I need you to write the link because just writing solutions within a week you'll be regretting. You'll be wishing you had written the the question we did down so you can go back to it. So this is May June 2024 paper 41. Write it down guys.

[01:24:00]I know you need it. That is why I'm saying you should write it down.

[01:24:04]Write down to say May June 2024 paper 41. Now write question seven.

[01:24:16]Write question seven. Then we go down and we do polymerization.

[01:24:22]Right? Let's do the polymerization question now. Number seven.

[01:24:27]Uh, empirical formula. No. Molecular formula. No. Here is a section of a polymer. Ooh, okay. Section of a polymer. Draw the displayed monomer that forms this. Oh, what is the repeat unit here? Repeat unit is this.

[01:24:50]Okay, I can take it like this. So I need at least two carbons. I need at least two carbon. So I can't take one carbon.

[01:24:57]I need at least two carbons. Then what do I do when I'm doing the monomer? I've said it over and over again. If you ever want to get it correct, remember to put the double bond.

[01:25:11]Then remove these ones. Then now your double bond is like this.

[01:25:18]And you can put your carbons.

[01:25:25]Are we together here? It then bonds with Look, look students, don't let me down. Carbon double bond to carbon.

[01:25:40]This is to CH3.

[01:25:44]This is to CH3.

[01:25:46]Then here is to H. You can actually put it like this to CH3 and to H.

[01:25:58]Yes. CH3 here to H. Then it says name the monomer. What monomer is this?

[01:26:13]Here name the monomer here it's beaut you can see let me help you something which is so important when you are going to name something the first thing you always find is longest chain that you can move through carbons without raising your Here I can start at this carbon move like this like this like this without raising my hand. So the longest chain is four carbons. So it's but now where is the alken bond? If this is one that means it's between two and three. Remember alcohol and alkenes you tell us where they are. It's not part of polymerization but the naming you should just know. I'll teach you naming better when I have. So here it's between it's because when you do alkans and you do alcohols if you don't tell us where it is I'll be so disappointed because you'd have thrown away marks.

[01:27:26]So here you'd say this because it is on position two and three the double bond you take two as your position. It becomes but because it was going to be butine. It's but because it has four carbons. It's in because it's an alken.

[01:27:40]Now because it's on position two and three you say but then you say two then you say in. You could have said to butine but to in is the better way. Are we together?

[01:27:53]So here it was. Do you know how to come from polymer to monomer? Yes. How? I showed the repeat unit first. Then what do you do? You change the single bonds to double bonds and you remove the extension bonds.

[01:28:12]Are we together students? Are we together?

[01:28:22]Well done.

[01:28:34]Now, let's do this.

[01:28:39]Is it the same one? Yeah, this is the same one.

[01:28:48]October, November, 2024.

[01:28:51]Write question three polymers and say October November 2024.

[01:28:58]Okay, this is now October November 2024 and it's paper 41.

[01:29:15]Paper 41 and say question six. I love this question. Looks like it's fun.

[01:29:25]Looks like it's fun. October, November 2024, everybody. October, November, 2024. And we're doing paper 41. And we are doing question six. Let's quickly go through it and let's see. Did you write it down, Anita? You wrote it down, Anita.

[01:29:52]LTK, have you written it down?

[01:30:01]State the type of condensation.

[01:30:08]State the type of polymerization reaction where natural polyamides are made from. All these are condensation polymerization.

[01:30:16]All of them except for the addition polymerization guys. So this is condensation polymerization. State the term given to natural polyamides proteins.

[01:30:30]There we have an amino acid. Thank you so much for putting an amino acid. Then they said uh complete uh fig 6.2 to show the general structure of an amino acid.

[01:30:41]Okay. You want me to show the general structure of an amino acid? Here you put R. Here you put your double bond O. Then here you put N. And you put H. And you put H. This is way too easy. They got to make it harder. We know that there's an R here. If hydrogen is here. If hydrogen is here, then we put R here. So they got to make it harder. This is way too easy, man.

[01:31:06]This is way too easy. Now, next question. Next question. And they it's now saying part D is now saying you have an amino acid and another amino acid and another amino acid and they say can you now show us how you would get the protein. This is way too easy. So let's choose guys here. If I put N because they said it's N. So you put your N because there's N this side. Obviously he's left with one hydrogen. The other one is gone. They sold him out. And this other side obviously he's just C double bond O. Right? That's all that's left.

[01:31:47]This O will go. So here I remove the O.

[01:31:50]Here I remove one N. So I remove like this. Here I remove one N. Here I remove the O. Here I remove one N. Here I remove the O. It's kind of like the game. So let's now just join like that.

[01:32:02]So that means basically I have the CO which is here. Now I need NH. So if these ones were facing up, the next ones will be facing down. So N, the H is down here. And he joins. And there is C double bond O facing down again, which now joins to N with an H facing up. And they join like this, which now joins to C double bond O facing up. And it's like that. And we are done.

[01:32:30]Way too easy.

[01:32:33]Well, not now, chromatography man. Not now. We'll talk about you later. We ain't doing you right now.

[01:32:41]We We will not We'll talk about calculating RF values. But is this easy?

[01:32:48]You should master the boxes. Are you Are we together to Are we together?

[01:32:59]Well done.

[01:33:03]Kelly, are we together?

[01:33:12]and right now.

[01:33:23]Let's go to the next one.

[01:33:40]October, November 2024.

[01:33:52]Paper 42 number six.

[01:34:00]Yes.

[01:34:09]Have you done it? Write this. October, November 2024 is the next question. Now we are doing paper 42 and it's the same number. It's number six again. On the other one, it was number 68 is number six again.

[01:34:28]Let's see if there's any difference.

[01:34:29]Anyway, I mean they're very similar. You can see that the questions are very similar and we are getting used to them, man.

[01:34:36]So, let's see what they're saying.

[01:34:40]I don't want to read that. I want to read the question. I'm not going to read this. Okay, this is all not going to be read by me. I'm not reading that. I'm reading the question. The question is here on draw a circle around one amide linkage. one amide linkage really amide linkage is this one nitrogen meeting a carbon with a double bond oh that is what we call an amide linkage thank you uh show all the atoms and all of the bonds okay what is it uh this fig 6.2 shows two monomers needed to make the okay the monomers let's put it We know that it is a di caroxyic acid and here it's a diamine.

[01:35:33]So you put your amine on both sides.

[01:35:42]Right?

[01:35:48]Let's now say um name the other product in this polymerization.

[01:35:55]So two monomers needed to make the polymer. Show all the atoms and all the bonds in the functional groups. We have done it. Now name the other product.

[01:36:07]Name the other product that is going to be used in here.

[01:36:14]The other product formed. Oh, formed. Okay. Water.

[01:36:20]Water. The other product formed is water. It's released as a byproduct.

[01:36:26]I for I had missed the word formed. Hey, I was wondering what is going on. State the tame given to natural poly proteins.

[01:36:33]Natural polyamides. We talked about them. Name the type of monomers which are used to make natural polyamides.

[01:36:40]Natural polyamides in other words proteins. What monomer makes proteins?

[01:36:44]amino acids make proteins.

[01:36:49]Uh do they what do they want us to do here? They are now saying um complete to show of this monomer. One of the monomers which forms part of the protein has three carbon atoms. It's like this displayed three carbon atoms. Okay.

[01:37:12]Three carbon atoms.

[01:37:14]So, I'll put a carbon here and a carbon here because they said it has three and here it is like this because they said it must have three carbon atoms. They are trying to catch us. Natural polyamide. They are very Okay, let me give you a tip. Whenever you see the word natural polyamide, please don't even read it. Say protein.

[01:37:37]They are trying to trick you. They are trying to trick you. Monomer of protein is an amino acid. Here they said it has three carbons. You know that there's going to be one here, one here. So don't put an R because they've told you the number of carbons is total. They said three. So you put one more carbon here like that. And then this is what it is.

[01:37:57]Name the two types of monomer molecules needed to make a polyester. Darosilic acid.

[01:38:05]Dicaroxilic acid and dio. Because this is a polyester. If it was a polyamide, it would be a damine.

[01:38:14]So dial. Oh, now draw part of the structure and show two repeat units. Ah, two repeat units. Okay. So in other words, it's going to be four boxes because each repeat unit has two boxes.

[01:38:27]So if I start with a with I don't know shaded box or unshaded box, doesn't matter. Let's start with a shaded box.

[01:38:34]What I'm going to have this side I am going to have let me put N with an H.

[01:38:42]Then this side I will put no not N with an H. I'll put an O because we have we are doing the terilline. So terine has dial and dicaroxilic acid. So definitely on the other side it will be C double bond O like this then bonded to an O then bonded to another box or the other side is also an O rather because here remember you have a DO which means he was he was an alcohol on both sides and he's meeting another box which is a dicaroxilic acid which is like this and like this. So this is a dicaroxilic acid and he is joining to a dial which again happens the same thing. You make another box which is a dial. Okay dial which means he has all this side and all this side. He can continue then he is going to join to a dicapelic acid. Don't change the way we do it guys. Don't change the way we do it. I almost did and I almost got punished here. It's like this.

[01:39:51]Then you can do then you can do something like that. So this is what you have.

[01:39:58]This is going to be one repeat unit is this.

[01:40:05]Then the other one is this one.

[01:40:09]Are we together students? Are we together?

[01:40:22]Is this hard?

[01:40:29]Is this hard?

[01:40:37]No, it's not hard. I'll give you then you should do the the solutions and u we'll see how it goes.

[01:40:47]Right.