Chemistry Past Paper (No Exam Board or Year)

Test outline Upcoming Test: January 13th: Outline: Course Book Pages: pg 17-72 -please note that you must still be able to draw Lewis Structures in order to answer most questions related to this material and also have a sense of the trend of EN 2. Learning Goals: Course Book pg. 3 - LG #6-16 (these provide an overview of the topics, but if you do not look over every page that is noted above and just use these, you will miss content) 3. Reference Material: The usual Periodic Table Reference Page plus attached shapes (please note any info not included here MUST be memorized) 4. Format: The usual format- multiple choice, matching, short answer Lesrning goals its on: Draw Lewis structures for the compounds that result when atoms combine to form molecules using single, double, triple, coordinate bonds and valence shell expansion. Draw Lewis structures for the polyatomic ions and molecules that involve resonance. Calculate the formal charge on each atom of a molecular compound. Use the concept of formal charge to predict the favored Lewis structure for a given molecule. Use VSEPR theory to explain the shapes (including bond angles) of molecules with 2-6 pairs of electrons on a central atom. Predict the hybridization of a given atom in a molecule. Draw orbital box diagrams to show how atoms combine to form molecules. Distinguish between sigma and pi bonds and use orbital box diagrams to illustrate how they arise. Determine whether a molecule is polar or nonpolar by determining its net dipole. Describe each type of intermolecular force of attraction and predict the type of intermolecular attractive force for a given molecule. Explain how the type and strength of intermolecular forces affect physical properties such as melting and boiling points, surface tension, capillary action, viscosity, vapor pressure and solubility. Relate vapor pressure to temperature and boiling point. Describe how chromatography, distillation and crystallization can be used to separate the components of a mixture by taking advantage of the differential strength of intermolecular attractions. Explain the mechanisms involved in the formation of solutions of polar solutes in polar solvents and nonpolar solutes in nonpolar solvents. (Like dissolves like). Compare the bonding characteristics and physical properties of metallic, ionic, molecular, and covalent network crystals. Differentiate between substitutional and interstitial alloys. Lecture transcripts Nov 18 18:21 Whoever asked me after I've told you what you have to memorize. Do I have to memorize this? And I've already said it is going to have to memorize everything. 18:30 That's fine. Um, so did you know that I'm trying? Bye bye. Yes, I posted it. I think I asked, did I ask the spirit in the, did you see my post? 18:45 It's okay. Okay. Um, where's the video? How do I do this so I don't lose a document again? Oh! You guys are so smart. 19:03 ,...? Open link in a new tab or new window, no new tab. A new Google. Oh, I don't want that. 19:11 Thank you. That's great. So I have to click the tab. Okay. Got it. And now I have to sit with a commercial. 19:24 Oh. Oh. And may I will transform your tail of faith until you meet website? It's a commercial so we can, oh, you can skip it. 19:36 Just a minute. After you've mastered how to write electron dot formulas on it. Why doesn't it go to full screen? 19:44 Well, I cheat and we're kind of limited to the two-dimensional world. You have to really start thinking about how molecules really look. 19:52 That's three-dimensional world because that's the world that molecules actually live in. What? Oh, it's unusual, I'm very- Okay, I'm feeling very stressed for no reason. 20:15 Yes. How did- what did you just do, escape? Okay, how do I master how to write electron dot formulas on a piece of paper which is a flat sheet and we're kind of limited to the two-dimensional world. 20:28 You have to really start thinking about molecules really. So we're about to start thinking You really look in. The this. 20:41 Oh, fine. Okay. After you've mastered how to write- That's what's going to help me know how to do it for the next two weeks. 20:47 A flat sheet and we're kind of limited to the two-dimensional world. You have to really start thinking about it really look in a three-dimensional world because that's the world that molecules actually live in. 21:00 The simplest model for modeling this type of We'll see behavior and actually works rather well is called a they would shell electron terra repulsion theory. 21:10 And the name's probably scarier than it actually is as far as it works. We also just call it the B-S-E-P-R theory and then we kind of just say it all together. 21:20 Best for theory. So you'll hear me say best for theory from now on when I need a simple previous. So the way it works and the main kind of gives it away is you take your electrons dot for nothing. 21:32 You simply count. No. Electron regions around the central atom. And you realize that's each of those regions. She's a negatively charged region. 21:41 And so it's gonna repulse all the other negatively charged regions and they're gonna try to get away from each other. 21:48 They can't completely get away though because the nucleus of the central atom is holding them in. So what they do is they try to get away from each other but they're still held out of central atom. 22:00 This leads to distinct molecular shapes. Thanks. And the easiest one is two regions. You only have one atom on one side and one on the other and they try to get away from each other. 22:12 You get a fairly linear type molecule. And so that's the first one. Two regions gives you linear shape. The bond angle is one on their main. 22:23 Stepping up to the next one. Three regions. You count the regions around the central. There's three. If three regions try to get away from each other, you basically get a nice Bye. 22:34 It's kind of pie shaped by picking a pie and cutting it in the perfect thirds. So you get a 120 degree angle all the way around for those three regions. 22:43 Both of those regions are still plainer. They still look just fine on see the paper. It's winding up to four regions that you have to go to the third dimension. 22:52 You have to go to the third dimension. And what this gives you is the shape that we call a tetrahedron or tetrahedral geometry. 23:02 It's four regions around the central. All perfectly symmetric. And if you take a look and spin the model of the program and look at it, every region is equivalent. 23:12 And the bond angles are now down to one 0.5 degrees. That's a tetrahedron geometry. So as you can see, the bond angles are getting smaller because we'll bring it in more region. 23:25 We started out 180 for linear, 120 for trigonal pointer. Now we're down to 109.5 for tetrahedron. Boop. And for the Our group, it sums up most of what we'll use, especially in organic chemistry. 23:39 Now, in addition to those, you can have expanded a tet, which gets you 5 and 6 regions. So to handle those, you've got to go one step further. 23:52 Uh, the 5 regions is a little bit complicated, but it's really just a combination of 2 and 3. You're going to have 2 atoms linear, and then the other 3 are going to be and we'll be back in a whole planar perpendicular to that. 24:07 When you look at the shape, you see what we call a trigonal 5-pyramid. You call it a 5-pyramid because you can look at the pyramid going up to the top atom and down to the bottom atom, which are 2 real pyramid pointing in opposite directions. 24:23 That's trigonal 5-pyramid. The last one is 6 regions. When you get up to 6 regions, you get something that should look somewhat familiar if you've ever studied x, y, z. 24:34 The coordinate planes and coordinate points. Everything's 90 degrees apart, or 180. It's like the x, y, and the c-axis of 3-dimensional space. 24:45 You put 1 atom in each space, you get 6 total. On the angles are either 90, or they're 180. You might go, why is it off the angel when there's 6? 24:56 Well, if you close up, you take every point and make a line. You get a closed 3-dimensional object with a total of 3-dimensional space. 25:04 The whole of 8 sides. 8 side is in goes figure, is in pump dehedron. And so we call it in pump dehedral geometry. 25:12 So those are the other 2 that are part of desperate theory. When you put all 5 of those together, you've got all 5 of what we call our electronic geometries around the central atom. 25:24 And that is as a part of desperate theory. Okay. Oh, really? Okay. Okay. So any questions? Alright. So here are the base shapes. 25:50 These are the ones that have to be memorized. These are called the electronic geometries. Like how the electrons arrange based on repulsion. 26:05 I call them the baseline shapes. Or parent shapes. That's how I prefer to say it, but. So you have to memorize the trigonal planar tetrahedral trigonal bipramidal octahedral. 26:19 And the angles 180, 120, 109, 90, 120, 90. Okay. Yep. So I'm going to show you. So the tetrahedral, like, it's this with the. 26:34 This, like, triangle here is very nice, but when we draw these, we're going to draw the bond going behind. So this is tetrahedral here. 26:49 I'll let you look at these in a second, but. Do you see tetrahedral? I'm going to put it like this. 26:54 So two that are flat, which I've done here. Okay. These, this pair and that pair. One pointing at you. And one going behind at me. 27:03 So this means behind the page in chemistry. This is a different atom. And this means in front, like a wedge means in front, okay? 27:20 I'm not paying any attention to that. And the wedge I sometimes change it a little, like I'm not super worried about it. 27:36. Umm, I'm just showing you how you might visualize it. Doesn't mean I'm going to ask you to draw these. Umm, okay. 27:49 Alright. So this little, so this is just, again, the electron arrangement. These molecules, boys and girls, you can get on word. 27:58 Do you guys have word and you go to, I think it was an insert and then you can choose the picture and they have these and they have you can spin them around. 28:05 It's pretty awesome. Umm, actually I could show you. Watch me. I'll show you. Umm. Let me see if I remember how I got them. 28:21 So if you go to insert, uhh, I can't remember if it's icons, it might be icons. Then I did this a while ago. 28:31 Umm... I'm sure it's a 3D mode. No. Oh, 3D mode. That's it. Oh yeah. You're right. Sorry, I missed that one. 28:41 You're right. Thank you. Yeah. So if I do, like, this one. See? You can rotate it. No. This is the 5. 29:01 So you see how it's got a combination of the 3 and the 2. Alright, you. We really appreciate trigonal bipyramidal, yeah. 29:08 So these angles here are 120. And these are 90, yeah. So if you want to visualize these, you can get these in word and you can play around with them. 29:19 It's kinda neat that you can do that. It doesn't just, what do you mean? These bonds are all the same, so it doesn't matter. 29:30 But that could matter, Jacob. We'll talk about it after. After. What do we have to see? You could, but you don't have to. 29:37 Do you want to say more things? Yeah, it's 180. Sometimes you see that listed, but you can say 180. It's totally valid. 29:46 But you don't have to. Okay, um. So back, so that's where I got all these pictures here. So they're here as well. 29:55 Okay, so this little chart, guys, what do I have to do, Mrs. M? On a test, I could give you a chart like this. 30:02 The first step is always to draw the Lewis... Diagram, okay? So beryllium, remember, is an exception. It has less than eight. 30:11 It's probably why we teach this. Remember, I said, I probably wouldn't teach it if it wasn't for something that comes later. 30:17 So you have the full representation of all possible shapes, okay? How many bonding pairs are there around beryllium? I'm not interested in the electrons around fluorine. 30:27 Two. So you look up the shape name or you memorize a shape name for two, it's linear. here. My body tears. 30:34 values. That is a bonding pair of electrons, okay? Angle 180. The diagram of the shape, I'm going to use a ball and stick model. 30:47 There it is. This angle is 180. Where skipping polarity, we'll go back to it later, just remind me, okay? Okay. 31:04 The next- Next one, the Lewis structure can be drawn however you want. I'm not paying attention to the shape when I draw the Lewis structure. 31:13 I'm just drawing the Lewis structure that comes out. So that's what I did here. Please do not add a pair of electrons on boron. 31:22 It doesn't have any more. It has three. You've a lot of kids want to make an octet, but you can't just really nearly add electrons. 31:30 Yeah, it's an exception. Good. So this has one, two, three pairs. Cheers. What's the shape for three pairs? Yeah, try trigonal. 31:41 Planar means flat. It's on two dimensions. So the angles here are 120. So you would do, um, like this. Yes. 31:55 I like the video. It's good. Trigonal. I'll, I'll. Try, whatever, trigonal. Planar. P.L. It. They're here too. If you don't, can't read my writing, it's here. 32:13 Okay, it's, we're going in order. Tetrahedral. Tetrahedral. Can you do the rest for homework? Yeah. Okay. It's the way I did it before. 32:35 4. Like that? These diagrams are a walk in the park compared to what we're going to do, so enjoy them. 33:01 You'll be like, remember when I was whining about- What the diagram? Because it's sticking out of the page. 33:18 There are a million ways to drive. I chose this orientation. You can do two sticking out, one sticking behind it. 33:26 Like, pick, pick your, okay? So Jacob, I did it like this. One of you wanted me to flap, okay? Yeah. 33:35 And if you that. gone. Alright, so. This is one word, but I'll. So the angle is 109.5 here. 120? Twenty 90. 34:07 You could say 180. Adam wants to also say 180. Yeah. So I'm not drawing it in its shape here. I'm just drawing the Lewis structure. 34:28 Phosphorus is expanded. It's octet. It's allowed. loud. So... So, This is 5... I didn't put a big enough box for the name. 34:53 Okay, so I'll show you how I draw it. I do the 180 like this. Okay. There's one here. There's one going behind. 35:04 One going in 5. That's right. So, if I go to the Word document, I'll show you how I've drawn it. 35:13 Like, you couldn't orient it in many different ways. Yep, this is how I've drawn it. See? This is the bond that T behind in front. 35:27 Okay, that's how I can, Doesn't matter. You want to do two, like, it doesn't matter. Bye bye. What are Dylan? 35:37 I feel like I like this, but you want to put, you can put two in front, one behind. Umm, it's like a, like, it doesn't matter. 35:51 Umm, okay. And my triangles, my wedges start to look very sloppy, don't they? Okay. Which ones do you want to put in front of? 36:03 Umm, okay. Which do you. One 80. I'm getting a clutter in my diagram, I'm not gonna. Sorry? Uhh, if I want that I would ask you. 36:25 Like, yeah. I, you don't have to hunt if, like, I only do it if you're asked. I may or may not ask. 36:38. Okay, it gets annoying to do all these lone pairs, so I can tell you a trick to not do this on the test, but I'll let you do it on your notes. 36:46 Sometimes you see books doing this. Do not do this on a test. I want to see the pairs, but. Okay. 37:22 On the test, you draw the full dots or X's, okay, but like, if you want to do it like that, here you can. 37:26 Okay, so six. Yeah, it's faster. Mr. And I'm telling you that so there should be no- Oh my god, I told you that. 37:49 It's done in books and stuff, but I'm telling you, I want to see the pairs. Yeah. Like, kinda it's like- Yeah. 38:05 Yeah. That's like the tr- I'm not really worried about, like, drawing a perfect, you know. There are many ways you can draw, Jalen. 38:24 I picked this one. What do you want to do? This? It's very hard to show a direct front and back here. 38:34 That's why it's not done that way. Like- The front, you would have- like, you can't show that here, like, directly behind and in front. 38:41 That's the- that's the issue. That's why I picked this orientation, because it's like, at an angle, so it's easier to draw. 38:56 This is a theory. No, but they have- it works. Yeah. I don't know how they do it, but they can. 39:06 Yeah. We're not doing that- we- yes, but not right now, right? We have to do a lot more before we understand that. 39:15 Sorry, Spencer. I don't know how you would do that. That's what Jalen just asked me. If you do it cross, how do you show it, like, directly behind and in front? 39:29 It's covered. You can't see the behind one right now. Do understand? This one is like- Yes. It's kinda hard. Thank you. 39:36 So it's not really shown that way. So you wanna draw it a little twisted. It doesn't matter. Do what you like. 39:47 I like it like this, so that's how I've drawn it. But, you know, it's up to you. I think it's harder to draw it in any other way. 39:55 Sorry. These lines mean it's behind the page, these lines mean in front. Okay? So Evie, if I go here, um, Subs by.zeoranger.co.uk Is there like one? 40:16 Oh, it's right here. So the octahedral is this one? No, not that one. Oh here, yeah, thank you. So look. 40:36 Look. If you draw it like this. Right. So that's what I'm saying Spencer. It's very difficult. So instead, I have drawn it like this, kinda. 40:50 I mean, even then, I guess the front ones could cover. So I tilted it a little bit. But I have behind, behind, in front, in front. 40:58 Okay. Okay. Everybody good? Actually, I'm gonna go back to that. We're not ready. That's, that's like a while. Okay. So we have to understand all the shapes first. 41:19 Umm. The double bond, that's actually a good question. You just count it as one pair. Don't count it twice. They're not separating. 41:26 Double bonds? No. No. Cause there's something about double bonds I have to teach you. It's not like the same. Which comes later. 41:35 So guys, did you hear his question? Question. If you have a double bond, you're gonna count this as one region or one region. 41:42 You don't count the double bond as two, one, two, three. This part of the double bond is doing, is like, there's something here that I have to tell you about later. 41:51 And it's not actually on the same plane as this one. So it, it's just this repelling this. So treat it like one, if there's a double or triple bond, okay? 42:00 We're gonna do that, explore that a little later. Yeah, maybe. Maybe I should change that to electron regions. But, as I think about it, but yeah, don't just go one too yet. 42:14 But I have double bonds in a separate like discussion coming, okay? You do the same thing, but like, they're gonna, um, it's not so typical that you would have, um, like you just do the, just we wouldn't even do the, show the double. 42:33 You're just gonna do like the dot dash and wedge. You don't even show the, double, because the electrons of the double, the second pair, are not on the same plane as those. 42:42 They're not, it's different. But I'll, that means nothing to you right now. So just treat it like a single, okay? 42:49 For now. Umm. Okay. Do you see this molecule here? Sorry, I'm gonna bring it down.. What shape is this one? 43:13 It's a four, right? Oh my god. It's tetrahedral, yes? Yeah. It looks, the angles look a little weird, right? Okay. 43:28 Okay. So when you, yeah. So what this is representing? See this, like, slightly colored ball here? This is a little bit that's it. 43:37 This is of electrons. No longer a bond pair attached to atoms. So bond pair means that we had the situation like this. 43:47 These are all bond pairs. This would be tetrahedral 109. I haven't drawn it in its shape. But what if we have one lone pair instead, three bond pairs? 43:58 The base shape is tetrahedral. That's why I called it a baseline shape. Four best-of-range a tetrahedral. But if one of them is a lone pair, it's going to affect the angles. 44:07 Why? The electrons here and here have a different amount of, like, electron charge, or charge, I should say. Why? Because these electrons are being shared between two atoms. 44:21 They're pulled by the electronegativity of these atoms. They get thinned out in this region. Let's say they're pulled more toward this white ball. 44:30 Like it has a higher electronegativity, like fluorine. Then those electrons are going to be pulled a little closer to that. 44:35 That weakens the bond. on Thursday. There's less electron material here. The repulsive force is not as strong when there's less charge, basically, whereas this is a full set of electrons. 44:47 They're not being shared by any atom. The repulsive force on these guys is much greater. Okay, so that's going to push these guys a little closer than what you would expect for four things around. 45:02 So all the angles, the base angles, 120, 109. 9. Etc. They're going to slightly shift to a smaller angle if you don't have all of the same kind of electron, which we did. 45:16 Bon, bon, bon, bon. If one of them is alone, that angle is a little less than what you'd expect for four. 45:23 Okay? Because lone pair can repel a bond pair more strongly. And if you added another lone pair, if this was a lone pair, that repulsion lone to lone is the greatest. 45:35 That's the full amount of charge. I encourage. Bye. Full amount of charge, greatest repulsion, they want to be farthest. Okay? 45:42 So that's going to shift the bond pair that can't compete as much a bit closer. So that's what we want to look at now. 45:48 Um, so that's what it says here. So lone pairs occupy more space than bonding pairs. There's no atoms tagging at them. 45:57 So they're going to end up being more concentrated charge, repelling more strongly. This is the order. So lone pair to room, lone pair are the strongest repulsion. 46:07.. So these guys repel most. Should we know this? Yeah. And then bond to bond, repel least. So if you have all of these guys in an ad in a molecule, which angle would be the greatest, lone to lone, or bond to bond? 46:29 Yes. So this would be the greatest separation or angle.. Okay. No, we want to be, what do you mean? The, what separates them the most is the, is what we want. 46:50 They want to be most separated. But sometimes they can't be equally far apart because of lone pairs win the battle and get farther. 47:00 That's what I'm saying. Yeah. So the, a central atom that has both on lawn, low, sorry, both lone and bond will have the lone pair. 47:07 here. is farthest. And the bond pairs will be closest. Farthest. Lone to lone is farthest. Next is the lone to a bond and then bond to a bond. 47:36 We're going to look at. Chlorines, electrons, unless it's the center atom, are irrelevant. We are talking about the electrons around the other atoms don't influence the shape of the molecule. 47:55 Just around the center atom always. Okay. So here are the steps, boys and girls, and I'll show it to you for this arrangement. 48:04 You need to draw the Lewis structure from the chemical formula first.. Okay. You count the number of electron pairs around the center atom. 48:13 How many total pairs are there here? One, two, three, four. Four pairs. Yeah, he wants to see atom ossip, I think. 48:30 Can you go see him, Adam? He's coming. Can you unlock the door, I don't know why it's locked? Good luck. 48:44 Okay. Okay. Of these four pairs, are they all bond pairs? What are their identities? Two are bond pairs. And two are lone pairs. 49:03 Okay. So if they were all bond pairs, it would be tetra- 3 but they are not. So the degree of repulsion is not the same between all these electrons, so the angles will not all be the same. 49:16 Long pair repel most, this angle here will be largest. And what angle would it be? Nope. What's the base angle for 4? 49:31 So it's gonna be greater than 109.5.. No. And over here, this here, is it gonna be greater or less than 109.5? 49:50 I'm gonna put two less than signs. You'll see why later. Yeah, well, like, less or lesser. Because there's another option with just one long pair, so that one's gonna be less, this one's less than less. 50:06 I'll show you that after. Keep going. Now. That's it. Okay, wait. I wanted to say something else. This is gonna affect the shape name. 50:14 The shape is based on just the bonds. So this is an angle, so this shape is bent or angular, for example, okay? 50:25 So the shape is controlled by only the bonds that are left. Spencer? answer. H2O has two long pair two bond pair. 50:39 They're not. It's just showing the three-dimensional geometry. Here's tetrahedral. Here's a long pair. Sticking there, pushing these closer. How do you show that? 50:51 You can't show that on a, Here's a long pair. This is the molecule we're looking at. These spread farther, these go a bit closer. 50:57 It goes closer by a degree or two, so like, you can't visually see that happen. So, don't worry. Are those long pairs for the off? 51:05 Yes, honey. The long pairs on peripheral, Addens are irrelevant to the shape, okay? Okay. So, we're going to look at it in the skin, but they're not taking on a different add-up point. 51:20 I usually put the bubble around the electron myself, but let's listen. Like, it wasn't a horrible picture, so, Yeah. Okay. 51:29 So, boys and girls, I, like, I added all these beautiful pictures in this to book this year to try to, you know, pick the one you like best, okay? 51:37 So, let's take a look Go. Look here. Oh, we're almost out of time. So, Here's the one for the number of electron groups, three. 51:47 So, with three pairs of electrons, if they're all bond, one, two, three are bond, it's trigonal planar. We saw that before, okay? 51:56 If one of them is alone, that's going to affect the degree of repulsion. These get a little closer. You can't tell that from the diagram, necessarily. 52:06 You've got to know that that's happening. That's all. You what we're going to So the shape here is bent or angular either is great, okay? 52:14 If they add up to four, four bond pairs, tetrahedral. But if one of them is alone and three of them are wronged, we get this trigonal pyramidal. 52:24 There's a triangle-based pyramid here, okay? And the angles will always be less than the previous one, the baseline angles that you memorize. 52:34 But I have another picture that shows that. And then, here, we're going. Too long, this is the one we just did. 52:41 This is going to be less than less than 109. Why do I do that? Because this one we're going to make less than 109, so less than less than. 52:48 If you want to memorize the exact angle, this is 107, that is 104. I'll put them both on you, do what you want, okay? 52:56 Okay? You're going to be given this. And we're going to have to determine it. So, you know, in universities, we're going to See time. 53:08 The atom, they're going to make you know this. So, if you want to start now, that's probably better, but I am going to give you this year. 53:18 No angles, just the names, huh? I will cut, no, it's regular. It's everybody. I will cut this out and provide this on a test. 53:34 Test, demo, whatever, exam. Yeah. Okay? I don't know, they change it every year. 53:49 You write the same exam. Sometimes it's in the gym. I forget, I think last year they just divided the whole hallway, you just went into a room that they designated. 54:01 But it's, everybody's writing the same thing. I don't, it just depends on what other exams are going on. So, it's like there's the entire grade, 10 grade writing, they might be. 54:09 It's the gym for that. Because there's fewer grade 11s and use the classrooms for that. I like it. I'm not involved in that, so I have no say. 54:16 Yeah, hun. This is an honor test, right? This is on a test, not a December test. Okay, we'll continue next class, guys. 54:24 Yeah, it'll be on the winter break. Yeah, after the, after the, after the, after the, yep. Yup. Thanks, guys. Have a good day. 54:34 See you tomorrow. Oh, excellent. You don't even Bye bye. No, how interesting it is yet. You just wait. I don't wanna go. 54:43 No. Nov 19 00:10 Okay. So we did this right here. I showed you the video yesterday. Okay. Oh yeah, I memorized this. Oh yeah, we did all this. 00:24 Oh, amazing. Oh. Okay. So did we talk about what the lone pairs do, guys? They repel more, right? Okay. So these are the, this is a nice little chart. 00:38 It doesn't have the angles in this one, but it's pretty nice. So when you have a lone pair, just to remind you, these guys repel the most, like lone pair to lone pair. 00:50 So this angle between these guys, if you could get an angle would be the greatest, this one would be the smallest. 00:57 So if you look at this picture here, this one has all the angles. Alls. And then those, like, you know, the wedge, the bonds are shown as wedges, et cetera. 01:06 So you're only needing to memorize this, this first column, which is your parent shapes, right? So the angles you see when you have lone pairs deviate from those main angles. 01:17 So this one here is going to be a little less than 120. Cause the lone pair repels more, pushing these a little closer. 01:25 So we're talking like 117. The deviations, like by a few degrees, not much. Thank much. Okay? This is 109 or 109.5, um, as is sometimes written. 01:35 So one lone pair, smaller than 109. Two lone pairs, even smaller. So you can just use two lesson sites. Okay? 01:43 This one is about, like, if you wanted numbers, if you preferred, it's about 107. And then this one's about 104. 01:51 Um, but just saying the lesson signs is good enough for me. Okay? Now, with this shape here, the trigonal bipyramidal, which is here, year. 02:00 8 There are two angles. I mean, even three, if you want to do the 180 here, but you don't have to. 02:06 So, when you're at the 90 degree position, that position and this position, those are called axial positions. And the atom is in that position. 02:15 Or axial atoms. So these are the axial position. Okay? And when you're on the triangle, like, you're, you're, I guess, along the, you know, this plane, the, Go ahead. 02:30 Uh, I don't know what plane would call that, but the Z plane, I guess, because it's out of the page back. 02:36 That's the equatorial position. Or these are equatorial atoms. Okay. So, beginning with this shape, if we were to have a shape where one of the pairs was lone, we have an option of putting the lone pair here, or putting the lone pair along one of the equatorial positions. 02:54 Remember that lone pairs want to minimize their attraction, interaction, repulsion, with the Yup. So, which, do you think there's like less, a little more favorable, like, a position, the one starting here, or starting here, do you think? 03:12 Like, where should I put the lone pair first? So, if you put it at the top, which a lot of kids say, you're gonna have three 90-degree angles, a 90-degree to this guy, a 90-degree to that guy, and a 90-degree to that guy. 03:28 Well, 90 degrees put some pretty good angle. Close, okay? Right, so if you put it here, you have 120, 120, and 290 degrees, that's a little better. 03:42 So, it, they usually the lone pairs will go equatorial first, okay? Um, so we're gonna take this position, this position, this position first. 03:53 So, if you see that drawn here, um, so see how they started replacing in the equatorial. AllY So, this is called the seesaw, here's the seesaw, there's the fulcrum, I guess, if you turn it sideways, that's the seesaw, okay? 04:09 Um, if you continue to remove electrons, you continue to remove them along that 120, there's two here's, you can continue, you can, if you want to draw this, you can put the lone pair here and there, you don't have that, they just flip the molecule, but it doesn't matter. 04:23 So, this angle would be the greatest angle, these are shoved a little closer than 90, you can see this. They just, it looks like a 90. 04:31 Bye. 90 here, the deviation's so small, like we don't draw it, okay? This is a T shape, here's the T, right there, okay? 04:37 And then if we continue to remove along that plane, then we have a linear. There's no deviation here from the angle, because these are along the same plane and they're pushing equally that way and that way, so it's, it stays at 180, this one, okay? 04:53 Um, and that would be linear, remember we named the shape based on what's left, yeah? See you soon! You want me to show you in real life? 05:06 So if you're looking here, if I, if I remove these two like on this plane, uh, sorry, that didn't come out. 05:19 T. So there's a long pair here and a little pair here. This is gonna be a little pushed a little over, but it's not a perfect T. 05:29 No, if these are all I mean, it's a little less than, yeah, we only, we don't really, I didn't report the 180, but yeah, it'd be less than. 05:38 We don't, the deviation is like a couple of degrees, so visually you wouldn't necessarily be able to see exactly. So it's not usually drawn, you just, what we do is we just put a less than, okay? 05:48 Also for the chapter he really does. You can't have one bond and call it a shape. We need a minimum of three atoms to call a shape. 05:59 So we don't, we don't keep going.. Because if you remove this, you just have a bond. A diatomic, a diatomic, we don't give it a shape name. 06:10 It's just a bond. So you need a minimum of three. That's why it stops here. That's why this one stopped here. 06:16 One, two, three atoms. If you just have two atoms, it's not a shape. It's just a bond. Yeah. Yeah. This is the angle that you can see there's a lot of volume on it. 06:30 Um, Well, I mean, we still have to understand what's happening in the molecule. It could have an impact on some of the properties, which we'll talk about later in terms of like, um, if one has a lone pair and one doesn't, that's gonna affect something about the properties. 06:48 You're gonna see that later. So it is important. I mean, not necessarily, like, the angle part of it, but when you have a lone versus when you don't, which does, yes, affect the angle and the shape of it. 07:01 Thank you. That affects something about the molecule that impacts properties, if that makes sense. So, Dylan, we have a bunch of things to learn before we can assess that. 07:12 Okay? Um, well, maybe this class will get to, we'll get a glimpse of it. Okay? Yeah. Mhm. It's 180 no because if you Oh, sorry. 07:32 T-shape. No. T-shape is less than. One. Because when you have lone pairs, um, I'm gonna move this here. Oh, no, this is T-shape, sorry. 07:44 Yeah, because it's not, these are not perfectly symmetrical. You need a counterbalancing one here on the triangle. You don't have that. 07:52 So these push away and they're pushing away impacts this a little bit. Okay? And these guys here a little bit. 08:01 You Sorry, let me put a lone pair here. These where I haven't put atoms are lone pairs. These push more, which is gonna shift this a little bit and shift this a little bit. 08:13 What are ex-, what are you talking about? 08:27 This is gonna be a little here. But it's not ever drawn that way. Okay. You just, all we do is write less than 90. 08:35 Oh, sorry. The other way around. The other way around. Sorry. Sorry. I wasn't paying attention to where the lone pairs were. 08:42 Yeah, yeah. Sorry. The other way around. Sorry. I didn't look to see where these guys were yet. It says less than 90. 08:51 See? Less than 90. Okay? And then over here, you don't have that. Cause this is, these are symmetrical positions. Right. 09:01 So. Yeah. Okay? So all the linear will always be 180. Okay? Umm, in this position, it's right in this one here, the octahedral guys. 09:14 Um, sorry, these atoms are different but kinda gives it away. But when I, the first time I replaced with a lone pair, it doesn't matter where it goes cause all the angles are the same. 09:26 Okay? So let's say that's a lone pair. The next time there's another lone pair. So two. Thank you. I appreciate it. 09:32 Lone four bond. That lone pair goes here, instead of here. This one's obvious. Why? Why would, like, two lone pairs arranged like this instead of like this? 09:45 Yeah, they're, you want the lone pairs to be farthest if you can. So this would put them at a 90. 09:52 This puts them at 180. Would that affect these angles and make them less than 90? Or would they be 90? 09:59 Sorry? Sorry? The counterbalance. The counterbalance. Alice. Perfectly, exactly. So when there's no lone pair here and there's an atom, this puckers a little bit. 10:07 But, with this pushing equally but in an opposite direction, they're all 90. So this should save for square pyramid. Oh, this is wrong. 10:16 Oh, wait, oh, sorry. I was looking at the wrong one. Square planer. So these are 90. See how it's labeled 90. 10:21 But this one would be less than 90, okay? Uh, again, less than 90 because you have a counterbalance here, but not here. 10:30 Okay? But in this one, you Bye bye. Counterbalance, counterbalance, so 1-8. Okay? Question, Adam? Yeah. It's trigonal bipyramidal because that's the only one that starts with two different angles where there's an option. 10:52 Oh. No, it up, sorry, the equatorial axial situation only applies to trigonal bipyramidal. Oh, okay. Like, Thank you. Because that's the only shape that starts off with two angles. 11:05 All the other ones start off with one angle. Okay? So then there's a choice of where to, like a difference in where to position the lone pairs. 11:16 Uh, Edan? Why is, like, why is the two shapes of a circle? There, we, honey, they differ by two degrees. 11:26 Like, you want to draw it less than 90, go ahead. It's not done that way. Cause it's a, it's a minuscule We'll do it. 11:32 We just label it. Honey, this is, like, the artist's rendition. I don't know what to tell you we've done. Do you want me to, like, email them and tell them we're not happy with this picture? 11:47 Like, honey, I, like, I, like, are you doubting it? Like, I don't know what the question is. I'm not measuring your angles if you draw this. 11:58 If you label them not less than 90, but you've drawn them perfectly 90. 90. Not. Don't worry it because that's often what is done. 12:04 Okay? So not an, like, not a big deal. But, like, you know, if you want to pucker it a little bit, that's fine. 12:13 I'm not worried about it. Okay, so let's try, um, these structures here. Lewis structure. So this is an odd one for you. 12:26 Just accept. Sometimes I'm going to say accept. This isn't incomplete octet. So 10 has how many valence electrons? Four, yeah. 12:35 So we're going to do a chlorine here. I am not drawing this in the proper shape. I'm simply drawing a Lewis structure. 12:43 The other two electrons are like this. You see that? So we're going to pair them because it's not typical that you would leave them unpaired. 12:51 This is an incomplete octet. It's like beryllium and boron. I will not ask you this one. I just wanted to give you something different. 12:58 How many bond pairs do you see here? Two. How many lone? Come on. One. One. So the total is? Three. 13:10 The lone pairs on peripheral atoms do not affect the shape. They don't affect how these atoms are range around that center. 13:17 Okay? So when I count electron pairs, I'm counting only around the center atom. Okay? It's a song that I know, you know that. 13:30 Fix the handle if you want to. Like. Okay. Do you want to add in honey? You can. But when I started all of this, okay? 13:38 Do you see how I highlighted this? I do it for a reason. Center atom. Okay? Umm, sorry. What's your question, Jacob? 13:49 What is it asking? Two plus one is three. Okay? Why do we do that? Why do I ask you to total it? 14:00 Because you need to go to the third column. Let me know. Not the second column. That's the baseline shape for three. 14:07 Three pairs arrange at 120. Are they all the same kind of pair? No. One's alone, Jayla. One's alone, so the shape of this molecule is one lone-two bonds. 14:24 Bents are angular less than 120. Okay? Yes. You can just write one of them. the T No, it is not. 14:36 To be called trigonal planar, you need to have three bond pairs. Cause that's a triangle. This is not. There's no- the shape names are based on the bonds that remain not the lone pairs. 14:48 Okay? So to diagram this, I usually do this. Yes, Jayla. Uh. Sorry? Oh. You can put a bubble. I'm not going to be do that. 15:02 Oh, not mandatory. It's okay, like, whatever. Yeah? It's this one, hun. I drew this. 15:34 We're good. We're gonna go to the- what I'm doing is I'm going to- this is the total electron groups. But then if they're out to three bond, we're here. 15:45 If there's one lone two bond, we're here. Okay? Because we need to look at the total because that's the best arrangement for three, right? 15:54 Like, a lot of kids will do the laxidentally look, oh, bond pairs will go to the shape for two, but it's not. 16:01 Yeah. So be careful. That's why-. Like, this- this- for this, you're going to the row and then you're going across to see, okay? 16:10 By row, I mean, like, in that picture. Yeah. Okay. So NH3 boys and girls looks like this. So this is obviously an order. 16:22 So we have- the first one is bond pairs. So three bond pairs, one lone, it adds up to four. So the base shape for this is tetrahedral, okay? 16:30 But with one being a lone, you're gonna have a- a greater repulsion between the lone and the bond, shifting them a little bit closer. 16:37 So that changes the name of the shape. It's trigonal pyramidal. And the angle is less than 109. If you write 109, it's fine, 109.5 usually is reported, but also 109, it doesn't matter. 16:54 Okay. So this is drawn like this. So everybody look up here. I- oh, don't draw this. This is tetrahedral. Well Okay. 17:03 This is how I have chosen to draw tetrahedral. Okay. So that's the- the base shape for tetrahedral. One of them is alone. 17:15 It does not matter who you replace. I'm gonna do it here and switch that to a bubble or you don't need a bubble, just put the lone pair there. 17:26 Okay. So just memorize one shape and then you just keep changing from that. If I have another lone pair, I'll change another one. 17:33 it. It's not necessarily drawn like that in those pictures because you can er- you can- your perspective on the molecule can be different. 17:40 Just pick a perspective and stick with that. Which is what I do. Yelly? It- to show you it's taking up more space than this. 17:51 It's like- No. It makes me laugh like you have to have a lone pair there. If you prefer to do this, god bless. 18:01 No Oh. Not some- some pictures will- images will show that. But it makes it- a line means two electrons. So I take issue with that because if you do this, it looks like there's two electrons and another two. 18:15 But as long as you understand that that's just trying to give you the perspective of- of the angle, it's fine. 18:21 But umm, I don't- it does not matter to me. Okay? If you like a bubble, you like- show a bubble. 18:27 You don't have to. I'm just trying to differentiate it for you and show that it's like coming out that way. 18:32 But. But, it's really like, a minor point. Dylan? I put the angles here. I'll tell you what I want, okay? 18:44 Label the angles don't- if I don't say that, you don't have to label them. Okay? But we already listed them here, so I didn't bother putting them here. 18:50 If I didn't have this column, I might label them, okay? It's up to you. Okay? Yes. Yeah. The angles that we're labeling, you might be thinking that this one's bigger misused. 19:02 That's not a bond A. on day. Bond angle is between bonds. This is not a bond. I would like argue it doesn't even make it- what is it? 19:13 Like how do you make an angle? You might be asked the angle, but it's not like you typically are interested in the bond angles, to be honest with you, okay? 19:21 I did tutor a kid one time in university, the professor did ask this angle. So they could ask you, but typically more typically we want bond angles, yeah? 19:30 More. Yeah, this one is more. This is us. I certainly would ask you to explain it, okay? But typically if I ask for the angle, it's like the bond angle, okay? 19:42 Um, but if I ask you to explain it, then you could label all this one's bigger or you tell me why, okay? 19:47 So water. Um, this- so this has 2, 2, and 4. Again, our base geometry is tetrahedral. This one's gonna be angular or bent. 20:01 You can use either name. It does not matter. Okay? Okay. And then because we have now 2 lone pairs, same scenario as before. 20:08 And by the way, if you want- if you prefer to measure like what typically is assigned here, it's like 107. 20:14 This is typically 104, but if you just say less than less than 109.5, I'm happy with that, okay? So I'm gonna keep the diagram the same as before, okay? 20:29 My wedge is always look different. I'm not worried about it. Bye. I felt like it. Do whatever you want. It's a Lewis structure. 20:41 I don't care. I change it up. Get used to it. It doesn't matter. That's the point I'm trying to make. 20:46 It doesn't matter. Okay. So I'm gonna replace the electrons here, okay? Leave everything as is. Most pictures will reorient this molecule. 20:56 So here's the tetrahedral. Normally, this is how I draw it. One at you, one back at me, these two flat. 21:02 If two of them are a little Love. Oh, I'll just take these out. So there's lone bubbles here. So it's oriented like this. 21:11 They just redraw it like this. With these coming back and out, okay? You don't have to do that. Keep one orientation and just always switch from that. 21:20 Doesn't matter to me. But that's what they do. The orientation of the picture will sometimes look different depending on how they're viewing the molecule. 21:27 Okay?. Sorry? If you show the dashed lines, you have to know that you have to just know. Did I do that? 21:47 Why didn't I do that? Because that looks like a pair of electrons and it makes it look like there's four. 21:53 If you want to do that, okay, boys and girls, it doesn't matter to me. The chances of me making you draw this are remote because you're going to have the pictures. 22:02 Like, I am going to give you a these pictures, so why on earth would I ask you and give you marks to copy this picture onto your paper? 22:09 Seriously? So don't get hung up on the diagrams, okay? Do not get hung up on the diagrams. If you want to continue to do this, God bless you. 22:20 Mrs. It does not care, okay? There's lots of ways of drawing it. Easy, honey, you couldn't do it. 22:35 Because look, like, look, I could look at the molecule with one in front, two behind. I could look at the molecule with, like, like, it depends how you orient it. 22:47 So I pick, I pick one orientation for tetrahedral, like this, flat front back, okay? And then, like, just like this, and then I keep it always that orientation every time, okay? 23:03 If it helps you to draw- You know, these bonds here, by all means, but you don't have to, okay? You can just put a bubble around them, and understand that they're, like, you know, it's okay. 23:17 Guys, the chances- like, I would not get hung up on this diagram, okay? Because you're gonna have the- you're gonna have- I'm gonna give you the ones you don't have to memorize. 23:26 The pictures are kinda here, like, it's just- so I wouldn't- it's not an emergency, okay? Um, okay. Okay. Is that four? 23:44 Is this correct, correct, what I did here? Yeah. What's the problem? So, sulfur has six. I've drawn one, two, three, four sulfur electrons. 23:56 It's missing two, okay? So, be careful to check that. So- Okay guys. Sorry, Jill. No, you cannot do that. That would be not marked correctly, honey. 24:19 Fluorine doesn't want to. Why would you do that? Do not give something up here that does not want to. So, that'll be wrong. 24:28 Like, Fluorine is coming into the relationship with one electron. Why would it take two? Like, wrong. I've- See, I do see that. 24:35 Be careful, okay? You can't just because something's possible do it in any scenario. Oxygen will take two, Jillin, because it wants two, but don't- don't do that to a halogen. 24:47 Okay, honey. That's different. It won't change the- not- anything we've done here will not change. Like, the shape won't change. 24:57 Nothing changed because the double will count as one, so it doesn't matter to me. Okay? Expanding lowers the formula. Normal charge, so it's better in that sense. 25:07 But it's not better for me, in terms of how I mark you, I don't care. Okay? Unless I've asked you specifically for the best one. 25:15 Which if I don't, it doesn't matter. Yes, usually that's the best one. Yeah. Doesn't really matter. I mean, now you're gonna start to, like, you know, I might deviate a little from- it doesn't matter, okay? 25:31 I'm not, like, showing its shape. I'm not showing the proper intake. Thank you for the patient. I just care that, like, you're bonding it correctly. 25:37 Everybody has an octet, all that stuff, okay? Umm, sorry. So we have, this is the number of bonds here, right? 25:44 Four, one, five. So we're in the trigonal bipyramidal row. Five, okay? So here's, when I drop, boys and girls, I just memorize one orientation that I always show for trigonal bipyramidal, like this, okay? 26:01 But if one of them is alone, where do I put the loan?. Equatorial or axial first? Doesn't matter which equatorial you draw it on. 26:10 Doesn't matter. Which one would you like me to, where would you like me to put the loan pair? Here? Yeah. 26:16 Okay. So I'll put it there. Now, do you want me to leave this bond here or put a bubble, what would you like? 26:26 Like Ellie likes them all. So guys it's drawn differently and like we out like see how they draw them here. 26:34 She's the, the, the ballons, what do you call this? Three-dimensional diagrams? I don't know. Here they've done ballons stick with bubbles. 26:43 Like there's lots of ways to do it. There's no like, only one way, you know? Just like handwriting. Do you guys all have the same handwriting? 26:52 No. It's kind of like that, okay? And it's understood that a person who knows chemistry will understand what's happening to these angles, okay? 27:02 So, the shape of this guys is. Thank guys. Thanks for CSA. CSA, yes. So, where's the CSA? Do you see there's the top of the CSA? 27:11 Here's the, is that called a fulcrum? What's that called? Fulcrum, right? Is it? I feel like I'm making that up. 27:18 Very good. Good job. Okay, next one. So, we have this split up up here. Here goes. One pair or two pairs. 27:39 Just one now. Sorry, evil. Okay, so this is gonna be three bond two loans, so letting up to five. So this one's your T shape. 27:54 Less than 90. There's only one bond on that. Thank you for watching. Equatorial planes, so I don't think we need to say less than 120. 28:08 Umm, okay, so I'm gonna draw the exact same thing that I did up there. But then one of these bonds is gonna get an electron. 28:18 It doesn't matter which, okay? Where would you like it? How about we go to the backside? Like that, okay? Oh, sorry. 28:28 No, there's gonna be more 90 degree angles. You can't favor only the lone pair hunt.. Like, I understand that the 180 seems really good, but then you're gonna have lots of 90s. 28:40 Umm, it actually is not considered a more favorable position because of that, okay? So it's never done that way. That would be wrong. 28:48 They go equatorial always first. So it's, it's like, I get that there's, will be a 180 between the two, but then each of them will have like lots of 90s. 29:01 More 90s. Sorry, it's supposed to be a wedge that's very poorly. We'll shortly. I can never remember if the wedge is thicker at the end. 29:08 I think it's thicker at the ends. It doesn't really matter. I guess I should, it's thicker at the end, I think, yeah. 29:16 That makes sense, I guess. Okay, next one, XCF2. Now, boys and girls, under no situation. When I get, no. When I give you a noble gas, you will see a noble gas, yes. 29:32 Make sure it's the center, Adam. Do not put it it as on the periphery ever and ever, okay? Noble gas is always center. 29:41 Noble gases don't bond. You saw it wrong. Well, you know, we're not satisfied with, you know, like a two year old, you tell the two year old know that you want to do it even more? 29:56 Like us, noble gases don't react? Oh yeah, I'm gonna make it react. Why do you think xenon could react and krypton? 30:04 Yeah. And that's it. Now, we're Yeah, I'm They can expand. Yeah, that's a good question Dylan. I don't have a good answer for that. 30:09 I haven't googled it in recent years. I'm gonna take a guess. Although I think this is a lame guess. Let's google it. 30:16 I'm gonna say that the argon atom is too small to accommodate. It is. Like, so much around it. And you would need to have two. 30:25 No, no, no. It's nothing to do with that. It's nothing to do with that. Spencer, can you? Oh, you're not grabbing your phone. 30:32 You're grabbing your water bottle. Ellie, you're on your phone. Why don't you go out?.. You like that, Dylan, eh? I'm always picking on him, but he's never listening. 30:43 But he's still there as well, which is maddening. I want him to fail so that I could say, see? I am right. 30:49 Sorry, Ellie. No, no, no, no, Okay, you know what? I didn't mean it like that. I'm just saying like, okay, okay, no, I want you to this time actually google it. 31:01 See again? Oh, he wasn't listening. See? Okay. Bye! Google this question. Why is, why, why can't they make, if they tell you, they're probably gonna say it's in in our gas. 31:11 That's the only thing, right? Oh, how about say, why does our gun not make compounds, but xenon does? Because technically it could expand its octet. 31:20 It's in row three, right? So, let's see if you can come up with, or ask somebody as chat GPT. Although, last time I asked, it's something. 31:28 It didn't give me anything that was helpful. What does it say?. I win. I win. I know nobody was fighting me on this. 31:44 It's a competition with self. I took an educated guess and I was right. It feels so good. It's with its size. 31:51 Yeah. But the, the, why I'm bothered by that is because we can put stuff around chlorine. Well, but I guess it's much, it is much more, a bit more smaller. 31:59 It's smaller and that maybe is the difference. I don't know. Anyway, okay, moving on. Nobody's, I was excited. Thank you. 32:05 Look at it as I am about that. Sorry, hun. I know. That's why, as I said it, I understand Ellie. 32:17 Like, that's why I was like, like, I think it's because of this, but it does seem a bit arbitrary. I know arbitrary. 32:23 I agree. But like, usually listen, what we do to explain things is we look at what's different about them. That is a different size. 32:30 Maybe that's what, like, I don't, like, we have to look at what's different to explain, right? Bye. But it does seem arbitrary because chlorine is right beside it. 32:39 It's like, is it that much bigger? Like, yeah. But you have to be able to accommodate two atoms. But I don't, because you have, if you split up one pair at least, right, like this one. 32:51 Which seems like, why wouldn't it? I don't know. I, I don't buy my own reason. That's why I was hesitating by Spencer. 32:58 This is a very good answer. Oh, it can. Oh, oh, like something we don't know. Oh, man. No, but that wouldn't be. 33:14 That's ridiculous. Not a molecule in my books. Like, I know what, what it's saying, but when we get to intermolecular forces, I'll explain why I hesitate. 33:27 I'm surprised that that would be called a molecule, really? What is it showing in the picture? Did it show a picture of it? 33:35 Oh, look at it later. Spencer, those attractions that, that it's referring to there, I don't use that name typically because there's some confusion around what it really means. 33:47 They're attractions between molecules. So it's like what holds a molecule to a molecule. So that's weird that they're saying that that's going to hold it and then call it a molecule, like it's weird. 34:01 You know, I mean, some bonds are attractions like, and I own them. I'm started. What I mean is it's like, it's like this attracting this normally is how, so then to say that we have that and it's called the molecule is a bit weird for me, but listen, chemistry can be weird, I guess. 34:21 So we're going to split up a pair, guys. I'm going to go like this. Okay, I usually don't do this whole sheet. 34:31 I usually do it for homework. I don't know what I'm doing here. Thank you. Thank you. Thank you. Bye. Is it? 34:42 It's not tea. Wait a second. You're like, wait a minute. Where are we on five? Yeah, one, two, three. Yeah, it's not tea. 34:51 That's fine. Like, it didn't make sense. How could it be a tea? There's no third bond here. Okay, so this one is, um, 90 or 180, I guess we could say. 35:02 Between the bonds, because they're doing bond angles, sorry. Sorry. There's various lineers. They assign the name based on the bonds that are there. 35:20 I guess I, sorry, I oriented this now differently, sorry, but the bonds make, the bonds are what makes the name. 35:27 Linear. No. What do you mean? Well, 180 would match linear. Yes. Yeah, linear would, I guess linear would always be 180. 35:38 Yeah. But like, I don't know how you would get T-shaped from that angle is what I'm, I'm saying, Elliot. Yeah, thank you, Ellie. 35:47 Look at him paying attention. Okay. Okay. Well, Adam will not make that change. I'll continue to do it like that. 36:01 Very sorry.. When your parents taught you to walk, did you like, were you surprised you could go in two directions? 36:13 Wow. I walked pretty early after this. God bless. We all are, it's okay. We're all walking now, so it doesn't matter. 36:25 I took my daughter at six months to the doctor to a pediatrician. And, uh, she wasn't rolling over, so of course as any mother I was totally paranoid. 36:34 And she, he goes, can she do this? I said. Thank you. Yes, can she do this? Yes. So what difference if she can't kick a soccer ball but can play the piano? 36:41 What's the difference? Like, okay. But we're supposed to look at these, like, what did they called again? Your parent. Miles Jones, yeah, I guess. 36:50 Anyway, and she wasn't, you know, you're a mom when you're a mom, you're a paranoid. She can roll over really great now. 36:57 Even though she couldn't at six months. Uh, anyway. Okay. Sorry. That was like, uh, uh, off topic, I guess. Okay. 37:08 Five. One, two, three, four, five. So this is the six. Uh, one, two, three, four, five, six, seven. Okay. So we have, uh, one, two, three, four, five, bonds, one loaned as up to six. 37:33 So this is square, pure middle, right? I think the sheet might say, please. Square pyramid, don't be alarmed if I write pure middle. 37:40 Same thing. And these angles are less than 90. So I always do the base shape like this with two behind. 37:49 Two in front. Um, and I'm gonna make the top one alone, but you can do the, doesn't matter which one. 37:58 Okay, bubble or no bubble, it's up to you. And there's one more. This one's square planar. Okay. These are gonna be 90 because the lone pair is gonna go in exactly opposite to the other one. 38:16 Okay, don't do this on a test, but I'm gonna cheat. You can show the lone pair as boys and girls. 38:22 Like this. But don't do it on a test. To be faster. Just as like bars around that. Okay. Uh, and here Zina would have two lone pairs. 38:33 So this is four bond, two lone adding up to six. Thanks. Am I boring you guys? You're like asleep in front of me. 38:42 We just started. I didn't sleep last night, so I don't know. Like you guys probably stuff like babies and you're passing out and here I am doing. 38:56 Uhh. This? Oh, I forgot the two atoms. Maybe I am. Yeah, sorry. Like that. They offset each other, yeah. Good job. 39:13 Look at me doing your homework for you. Wait, those two lone pairs, they should be, like, one is here. 39:30 See these green ones? Okay. Okay. What's next? Oh. So, remember this whole thing with equatorial and axial? Umm, okay. So, we usually make the lone pairs go in equatorial positions to minimize the repulsion. 39:51 You want these, these positions result in more crowding. Sorry, axial positions are more crowding because there's more 90 degree angles. 40:00 Remember I said that? So we would put the lone pairs equatorial. Now, I can never pronounce this word, so don't make Thank you for your what I mean when I try. 40:07 It doesn't come out right. A picofilicity. That wasn't too bad. That was good because I did it slowly. Okay. So, if you have something like, let's say I had you draw, um, pf2cl3, okay. 40:30 And we have the trigonal bipyramidal here. Oh, I should use the atoms just so that's clear. Sorry. Just watch for a second. 40:40 So here's my trigonal bipyramidal shape. Oh, my God. I'm so used to doing falls and sticks. I keep forgetting. Um, it's like on like, just muscle memory, I guess. 40:56 Okay. So we want to put the fluorines and the chlorines. Now, you guys might think, oh, she put chlorines. It's convenient to put them here on this equatorial. 41:04 But let's read what it says. The moral of it.. So, we negative elements. Have a greater tendency to occupy axial positions. 41:12 Cause there could be like, varieties. You could put F, C, L, like where we're going to put them. Yes. So that means the fluorine would go here in axial and the chlorines would go here. 41:23 Okay. Now, why would that be? Fluorine is the most electronegative. So it moves like some of the electrons closer to it, weakening this area or depleting this area of negative charge. 41:37.. Minima, like, that helps to offset the extra repulsion of these positions. No, no, no, no. It would be, it would be more than this one. 41:51 Is that what you mean? But they're not bonded to each other. Yes. But I don't know what phosphorus is. I don't have that on them rice. 42:03 But you would do the, you wanted to know the polarity of the bond. You would. you calculate the difference between F and P. 42:09 And then P and C. But I know P, I know the PF bond will be more polar than the PCL bond. 42:14 Well, eventually we're going to be interested in doing that. That's where we're headed. But. Okay, so. I'm just going to write electronegative. 42:27 Sloreen. With draws. You know, but by that, I mean shifts electron density. That's what the term we use to describe the electric electron material, um, toward it. 42:45 Um, so that would, which reduces charge there. And, um. 43:04 Come. So, the axial position shifts. Like, if you don't like withdraws. 43:21 Withdraws or shifts, the electron density toward it, which reduces charge there. And so the axial position, um, is, so the, the, let's rate the repulsion of the axial position is less problematic. 43:37 Cause it's, it's, it's less charge, right? Okay, so if you have a situation where you have a competition between where to put the atoms, always put the more electronegative axial first. 43:59 Okay, if I had another fluorine, if it was PF3, I would then have to go to a quatorial. Sorry? Okay. 44:07 Electronegative fluorine withdraws slash shifts. Electron density toward it, which reduces charge there. And so the repulsion of axial position, uh, I forgot, is, is less of a problem for it. 44:20 Is that okay, Evie? Sorry, is less of a problem for it. it brings it closer. So if you think of the electrons as a cloud, it's out this cloud, less charge, less repulsion to the chlorine, right? 44:42 So the 90 degree angle-ish situation is, is uh, less of a problem for it because there's not as much charge as there would be if chlorine was in that position. 44:51 Because it's less electronegative, less able to shift the electrons toward it. Okay? There's less charge in this spot. So if you imagine this as two negatives, this might be like 1.6 of a negative, because some of it shifted toward fluorine. 45:06 Like, that's how I think about it. , , Okay, and so less charge, less repulsion, so it's not as problematic to have it there compared to chlorine. 45:13 Okay? Alright. Polarity. Amazing. Okay, so remember we skipped that- that's fine. What? What? I don't want to help you. We're not going to see you for another Halloween. 45:34 What? I'm not schooled till my day. Oh my god. Well, that's all the more reason to take advantage of the last two minutes. 45:46 Okay, I actually already taught this to you. This is going to be, like, easy. Hopefully, let me just remind you of what this means. 45:55 If a molecule has a polar bond, does that automatically make it polar? Why not? out. They can cancel each other out. 46:05 So I want you to, Go back to this, Where did we have no long pairs? Over here? See these shapes here? 46:13 Do you think this is polar and non-polar linear? Assuming the atoms are the same. What about trigonal planar? Tetrahedral. What? 46:23 Tetrahedral. Trigonal by pyramidal. Because it's a combination of linear and trigonal. Octahedral. This is provided these atoms on the end are all the same. 46:34 If I change one of the atoms? Polar. Polar.. See? Told you we would fly through that. Because now you understand these are symmetrical shapes, right? 46:43 Now what is, what do long pairs do to the symmetry? Mess it up. So if it has long pairs, it's more likely to be polar. 46:51 Unless they themselves are symmetrical, okay? See? Now try to remember that, You subtract the electronegativity difference. But we don't need to do that. 47:02 We're gonna like, just go by the shape and assume it's different enough. Ellie? They love you. Yeah. Ohhh! Thank you very much. Nov 25 00:06 That's me being snarky, Ellie. Okay, okay, attention. Alright, so what's a bun dipole? This is on your test. Okay, okay, what so what's the- what's causing the difference in attraction? 00:33 Okay, so differing electronegativity? A result of the blank sharing. What do you think goes there? Unequal. It's okay. It's okay. 00:49 Unequal sharing of electrons between two atoms. You didn't finish reading the fact that it said electrons here, so wouldn't have made sense, okay, they weren't. 00:56 Okay, the term dipole means two ends. What kind of ends? And, It's north pole, south pole, or what? Negative and positive. 01:05 So in this case, a partial negative end and a partial positive end, which we use that symbol. Oh my god. 01:12 What is that? Is that an S? We learned it. We're like, what? I'm working so hard to teach this and you were like acting like you've never seen it before. 01:24 Shame. Go to the regular program. Or less than regular... I'm just joking. Okay. Environmental science for you. Okay. So, if, uh, if A has a greater electronegativity, does it get the partial negative or the partial positive? 01:44 Yes, because it attracts electrons better than B. Okay. And we say that the bond is polar. Alright. And we can represent the direction of a pole with an arrow. 01:58 Um, what do we call in math? This arrow. he he A vector. And in chemistry, that vector has a name. 02:04 It's called a dipole moment. I, this is, I did all of this with you. And it's represented by the arrow pointing in the direction to the more electronegative or less electronegative element. 02:16 Good. Now, here's the new stuff. And I eluded to this before already. Okay. So, um, everybody get this. I'm gonna switch this page. 02:28 Okay. So if we go back to our first. Shapes. When did we start the shapes? Okay. Now they're gonna be on your test. 02:37 I'm writing you a special test. Okay. So, do you see all these shapes, linear, trigonal, planar, tetrahedral? This atom, how does it compare to that atom? 02:51 Same. So, let's say it was fluorine. It would pull toward it that way. This would have a dipole moment in that direction. 03:00 What's this? Some of these dipole moments. Is this molecule polar? No. What about this shape? Where it pulls there, there, and there. 03:12 0. 0. Okay. If the atoms on the end here are the same, then what, then that means these molecules are non-polar. 03:26 Same for tetrahedral. Sometimes kids have issues with tetrahedral, but, uh, um, if I toss tetrahedral in the air, of course these atoms are different, so what I'm about to say doesn't make sense. 03:42 I need a green one. Okay. Here's tetrahedral, guys. This is a perfectly symmetrical shape. So if I toss this in the air, and it lands like that, yikes. 03:56 And then I toss it again. Can you tell whether it landed just, like, the surface? The atoms are the same as before. 04:02 They're different. You can't tell. It's totally symmetrical. That's, that's something different. Okay? So we are assuming, that's why I said this le, that these atoms are all the same. 04:14 In the cases where these atoms are all the same, and same thing here, this is the linear. This is the trigonal planar. 04:23 This is a symmetrical molecule. This would also be non-polar. This would pull, that would pull equally. This would pull, that would pull equally. 04:31. Each one of these baseline molecules, provided the terminal atoms are the same, are all non-polar. Okay? Yeah. Yeah. These geometries would produce non-polar molecules because. 05:01 because Oh, sorry. We're not talking about that right now. I'm sorry. I'm sorry. This is a very big butt. So in the cases where, because these geometries were not doing long pairs yet, we will answer every single question, do not worry. 05:46 But these geometries would produce non-polar molecules. Because there would be no net dipole. The bond dipoles would cancel. And this is only true. 05:56 Like, this is really an important point to provide it. All terminal atoms are I'm sorry. All right, identical. Okay. Okay. 06:13 I'm not going fast enough for this class. Just be, just write this down and then we will move on. Thank you, Jacob. 06:20 Thank you, Dylan. Great questions. Right now we're just doing this. We'll move faster. You write faster and we'll move faster. 06:28 Everybody got it? I got it. No oxygen. Peripheral. Adams attached in. Yes? Sorry. Sorry. Sorry? I know. Sorry. I know. 07:05 But now that's changing? It's gonna be normal for the rest of the year? No? Yeah. Welcome to chat. Not only are we gonna give you a million subjects, but we're gonna like, sometimes do them, sometimes not do them, and you never know what I know, it's crazy. 07:29 How easy will university be after this? of Okay. So, polar and non-polar. Okay. Polar and non-polar. They're all non-polar, so I am just gonna put an arrow, meaning this all fills down. 07:49 Got it? And here I was thinking that I did the best job ever, but I know I still didn't get everybody on the train. 08:08 It's okay. And these are non-polar because if their items are the same, it's symmetrical shape. This would pull, this would pull, this would pull equally. 08:19 Not, there would be no overall polarity. It's not that I pull would be zero. You may, I also discussed this like when we did electronegativity back, which you missed a lot. 08:29 I don't know if it was the one you missed. next. Then you may missed that one so you weren't like as quick on the bandwagon because I always like, I like pre-teach it sometimes in another place to make it go faster now. 08:40 So I, I don't know. So, like here too, this is, is this perfectly symmetrical? Exactly. So this shape would now no longer be non-polar. 08:51 That's what we're going to get to, but you've got the idea. But all those shapes as long as the atoms are the same, they would cancel, okay? 08:57 We fill this in? Okay. What else? Now, now we're uh, uh, okay. Continue, continue, continue. Okay. Now, in this situation, we start to have lone pairs. 09:08 Oh, sorry. I want to go back, pardon me, pardon me. Okay, here. Yeah, yeah, yeah, yeah. No worries. So we just did this situation. 09:16 To be polar, a molecule's geometry must be such that there is a zero. Oh, sorry. I can't read. I thought this was the non-polar one. 09:29 Okay. If polar bonds, okay. Okay. To be able You Yeah. Now we're switching it right. Sorry. I did not process that because I was expecting something different, but it's okay. 09:38 A molecule's geometry must be such that there is a, that's what the sentence didn't make sense. It was like processing it weird. 09:44 And it must be a net dipole to be polar now. Okay. Yeah. Oh, I was thinking of this page. This is where I was. 09:54 Okay. No, no, you're, that's like the individual bond dipole hunt. Okay. All right. So the, the net dipole means the sum of all of those. 10:05 Yeah. Like the sum of those poles. Okay. If polar bonds, okay. So here's the, the caveat. If polar bonds and lone pairs are symmetrically arranged. 10:17 This is the ones we just did. Okay. The molecule will have no net dipole and thus be non-polar. Okay. So now I've started to add lone pairs into the mix. 10:30 So let's like process.. Just a little bit. So if we did this, is this polar or non-polar? Okay. We're assuming these atoms are all identical. 10:49 I'm trying to shade some and not shade others. Okay. What if I took this same shape and change the atom to a different atom? 11:00 Would it still cancel? And so, No. Okay. This would pull differently than that. Sorry. They look like, I don't mean that the center atom is the same as that one. 11:08 Let's cross-hatch it. I don't know. Do something different. Okay. So this is now polar. The reason this is non-polar is there's no net dipole. 11:21 And we know that because it's perfectly symmetrical. Here, it's polar. This means there is a net dipole. you This molecule is asymmetrical or has less symmetry than before, I guess we could say, but I'll just call it asymmetrical. 11:40 Now Dylan asked about lone pairs before. If instead of this atom being an atom, if it was a lone pair, what do you think? 11:52 Polar or non-polar? Yeah, it's, it's equivalent to the situation. Okay. This would not counteract the poles of these equally. So this is still polar. 12:05 So that's what this sentence means, okay? If the polar bonds, which are like the bonds to the atoms, and the lone pairs are symmetrically arranged, there would be no net dipole. 12:18 If they're asymmetric, which would be this situation, it becomes polar. So what we're going to do, I'm going to go back to those sheets in a second, but should I start here? 12:29 Okay, I'll start with this. So, um. Um Well, maybe we'll go back here for a second. Sorry. Okay, if you look at these shapes here, so we know that this whole first column is non-polar. 12:42 Let's start to add lone pairs. Sorry, page 23. This is just to give you a visual. I'm not going to write anything here, because I have that other page. 12:53 So, if you look at this molecule here, polar or non-polar, do you think? Good. Is there any situation where I change one- on. 13:02 9 9 of these atoms? And it could possibly still be non-polar. No. In- in three, with three, these all have to be the same. 13:14 Okay? In order for it to be non-polar. We are assuming the bonds are polar, and that's how you're going to operate. 13:22 You're not going to worry about subtracting the differences. It'll take forever for you to check that. So we're using shape. 13:27 Dylan?.. We're not checking that. If- in chemistry, we don't bother. You assume if they're different, it's polar enough. We're not- we're not gonna- I'm not gonna trap you. 13:41 Okay? That's how we- because it'll take too long for you to check if- okay, huh? So we're gonna just assume if I give you different atoms, it's- it's gonna subtract to be greater than 0.5. 13:51 If- if not, I would indicate. Okay? So we're gonna base it on shape. Otherwise, it takes too long to check that and then check shape. 13:57 Okay? And that's kind of how we operate generally in chemistry. Um. I'm done. I had a kid one year or many years ago in AP. 14:06 She went to the States. And she took a- a multiple choice question that she sent to me. And she goes, what's the answer to this question? 14:11 And I answered it. And she goes, how did you know that? I answered whatever answer it was. And she goes, oh, I go, I know, because whenever the atoms are different, we just assume that assumption that it's- it's polar enough. 14:23 She goes, but I knew- she goes for whatever reason she knew the electronegativity differences. And so she subtracted it and called it non-polar. 14:31 And when she- she looked them up, she was right. But the teacher wanted to add her to answer the question based on my assumption. 14:38 Anyway, so she went back to the dean to argue it. And you know what she told me the teacher did? 14:43 It was like ridiculous. He changed the rule. So that he wouldn't have to give her the mark. He goes, oh, it's when they subtract to be.4 or l- l- later. 14:52 Sorry, no.3, he said..3 instead of.4, yeah. So I said to her, but I didn't think about it till after. 15:00 I go, so you're telling me now every hydrocarbon on the planet. Bye bye. It is polar. She should have said that to him. 15:05 So we're gonna change all of chemistry because of that. Anyway, I know. So it's like, I don't know. It was where I was crazy. 15:15 I was like, that happened another time to a kid I taught something to. And he answered a question based on knowing the real information. 15:24 And he got it wrong. He proved it mathematically. He went to the deans. And the deans like, well, you weren't supposed to know that. 15:30 We didn't give him a mark. I'm sorry. But he goes. Because he didn't care because he knew he was right. 15:35 But it was like. So now I tell every time I teach those topics, I tell the kids that story. But we're not. 15:40 That was a grade 12 issue. But this issue here. So generally they. If you. Me? No, that's a cons. I can't tell you what the problem is because you won't understand it. 15:52 It happens in grade 12. When we get to grade 12, I'll teach you what the kid did and why it's right. 15:58 And what he like. It was like he knew more than the rest of the kid. But he. Like, it's like not. 16:02 Come on. I know. Uhh, Emory. In the states. It's in Atlanta. Yeah. It was like, she didn't, she didn't, she didn't care because she knew she was right. 16:15 But it was just like. So she subtr- she in her mind, like they wanted to pick the most polar molecular. 16:21 I forget what the question was. But one of them involved bromine and she goes, oh, it's so far down. It's going to subtract to give non-polar. 16:28 But they don't want you to do that. They wanted you to like, assume based on shape. Like, what I mean. 16:33 I'm telling you to do. So, you know, but it's not fair. He's like, you walk in the room and you're going to change the rule. 16:41 Like, she didn't bother. Like, I know, like, I know, like, it's ridiculous. So I should have told her the comeback. 16:50 But by then it was too late to say, okay, hydrocarbons are polar now, really? But, I don't know, it was ridiculous. 16:57 Anyway, like, how ridiculous? Anyway, I, whatever, I should always remember that. We were like, both of us.. I'm mad about that. 17:05 Anyway, okay, so back over here. Umm, okay, so tetrahedral is non-polar. Is there any arrangement where I could change an atom or have a lone pair in this situation where I could still be non-polar? 17:21 Or no matter as soon as I change one or change two, it's polar. What are your thoughts? No, no, no, no. 17:31 Like, I mean the variations of the- Having them all the same. So, when I put a lone pair of Jalen, it's a lone pair or a different atom. 17:40 They function the same way in terms of like what it does to the symmetry. So, as soon as I change it to a lone pair or there was an atom that's different than these guys, polar, okay. 17:50 If I did that to two of the atoms, would that have the possibility of creating a non-polar situation? No. So in these two shapes, as soon as you have a different atom, or lone pairs, whatever, which the name of the shape changes, there's no, there's no situation where you could still have non-polarity 18:10. But that's not true with 5 and 6. So if you look at 5 and 6, one lone pair, what do you think this is? 18:18 Polar or non? Good. What about this situation? Polar. What about this one? Exactly. If the symmetrical positions, whether they're occupied by lone pairs, you or all the same atom. 18:36 If this was F-F-F, this could be C-L-C-L, but their poles oppose each other, it's non-polar, okay? So tetra, uhm, trigonal by pyramidal could produce a non-polar geometry if the electrons themselves are, uhm, symmetrically arranged, or the atoms that are different are symmetrically arranged, okay? 18:59 That's what that sentence means. I'll, I'll, there's a note coming on that. Bye. Look at these shapes here. Are any of these non-polar? 19:09 The linear is non-polar? Because- and the square planar, exactly. Okay? If this was a fluorine, where would I have to put the fluorine to make sure it stayed non-polar? 19:20 Bottom. Okay? Uh, well, we did those already. That was part of what we did, Mila, yeah. Yeah. Yeah. Yeah. It's an all-in-one. 19:32 That's it, you're right. Do you really look for the fluorine to make it non-polar? No. The only way in tetrahedral that could be perfectly symmetrical is- and cancel out is if they're all the same. 19:45 Like, if this is a ClCl, like, it- like if I- the- what I usually say is if I toss it in the air, you could see the difference between them. 19:54 Like, you lose- you lose a ton of symmetry, they will not cancel. Like, this- this- this- they have to be like the four corners of a tetrahedral, all the same to cancel. 20:02 If this is different than that, you I'm you a that it's not opposed properly by these. Yeah. Okay, so we're gonna- gonna go back to the note here. 20:11 Yeah. So the- if you want to know what the non-polar geometries are, I'll highlight them in yellow here, okay? So, all of these guys- can I- all of these guys are non-polar? 20:34. This is assuming the end atoms are the same. The non-polar- other non-polar is this one? Yeah. This one? Sorry. It's not like working very well here. 20:54 And this one. So- or these are the potential non-polar shapes, okay? It would never- but the thing is you can't just do that. 21:11 They won't arrange that way. Because this is the maximal- they have to go here to maximize all the best angles. 21:17 You'd have too many- you'd have a good 180, but then too many 90s, which is not favorable. So you can't just do that because you want to do that. 21:26 The lone pairs have to go on this- on the equatorial always. So because of that then, um, Seven. And even if you did put here lone pair, lone pair, these wouldn't be balanced, so it wouldn't make a difference, actually. 21:40 Right? Because you would have- wait. Oh, lone pair, lone pair, three atoms. Oh, no, it would be actually, because the three x, x, x, yeah. 21:49 Yeah. But it's not allowed for, like, this geometry, yeah. Um, okay. So back over here. Alright. So here are the considerations. 22:02 For molecules with three or four atoms. Okay, all lone pairs. All terminal- terminal atoms must be the same for the molecular be symmetrical non-polar. 22:09 Any other combination of different atoms or lone pairs will destroy the symmetry. Okay? So all of these non-polar. Okay? There's- we don't have- we have to have three atoms minimum to define a shape, so. 22:25 If we did this, we saw this one before. I'm gonna make it a square to be different. This is now. 22:34 Polar. All of the ones I draw here are polar. If you made it a lone pair, polar. Okay? Again, over here, if I change one of the atoms or one or more of the atoms, I'm gonna make this one a square. 22:56 Polar. Okay? If I have two lone pairs, There's two bond pairs polar. So the only way to get a non-polar is they're all the same. 23:09 Okay. Everybody okay? So, oh, yep. Spencer? This one, this atom is different. That's a square. No, it's not. These are pointing, Like, in the, in the 104.5 degree. 24:08 It's tetrahedral. So, like, if these two are lone pairs, in these poles, they're not, like, counteracted properly by, okay? You can't tell that from this diagram. 24:20 Uhm, okay. These guys are non-polar. If you want them to continue to be non-polar, you have to occupy the symmetrical positions. 24:33 So, what are the symmetric, The symmetrical positions in this? Yeah, so, if this was an X, to keep the, Good. 24:41 And then here, Y, Y, Y, Y, non. So, this is still non-polar. And if I wanted to do that with octahedral, Yeah, X, X, So, if I put a Y here, we're gonna have to be Adam. 25:11 You mean? Yeah, okay. How about that? Okay, non-polar. So, the symmetrical positions are like the opposing. Paula? My name? Oh, I guess you could think it's phosphorus. 25:29 How about we do, Zed? Zed, okay. Zed. Canada does Zed, right? Yeah. Sorry? Ehh. Ehh. Look, that opposite to that, these cancel. 25:50 That pull would cancel that pull. As long as the 180 positions are occupied by the same thing, it continues to cancel. 25:58 So, I switched all the 180s to be this, like, to show you.. Yeah, I'm just, I'm just creating, I'm just doing scenarios where it could be tricky. 26:10 If they're all Y or Z, it's, it's like this situation on jail. Yeah. Which is non, we already had Zed that was non-polar. 26:17 Yeah. Yeah, there's many. Yeah. They don't all have to be different. I'm just, yeah. Awesome. How we doing good? What? 26:30 What's not Wednesday. Oh, I have better put an announcement of that Wednesday. We're hosting a professor from University of from York University. 26:47 He's coming to some of the classes and have your lunch meeting. I know. Okay. Okay. I could replace it with Friday lunch. 27:01 Is that fine? I'll, I'll put an announcement over place it with.. Friday lunch. Am I, oh, no, I can't. I'm going to a tournament. 27:09 Thursday lunch. Oh, it's my day to go home. Oh, well. Okay. Bye. And just go outside. If nobody comes, I'll be very angry because I have a huge spare including, before lunch, after lunch, I could just go home. 27:22 You can help me so I can understand. Notice that you can do all sorts of homework. And just forget about the students. 27:28 I know. I've taught this so well you have videos. Come on. I don't know. I'll think about it. Maybe Thursday. 27:32 I'm not here. Oh, that's, Why doesn't care, otherwise you'd be like, Okay. Poison girls, put your pencils down. I'm going to use this as a white board. 27:46 So just everybody listen. Nobody write anything down. We will write down what we need. Everybody good? Okay. How am I going to do this? 27:55 CH4. This molecule here. Thank you. Oh my pain now, you feel it, my pain? Okay. Alright. So. Carbon, what's its valence configuration? 28:25 2S2, 2P4? We remember all this? Sorry. I meant 2P2. you. What's the of 4? Thank you. It would look like this. 28:38 Everybody good so far? Okay. Here's the problem. One problem. As I look at this, and then I look at the Lewis-Dryogram we draw, they don't jive. 28:48 Because this shows that I have a lone pair on carbon. Any lone pair here? Okay. That's a problem. Here's another problem. 28:58 Is that bond any different than that bond? Same bond. What are the bond angles?.. Oh my God. You can't base it on this picture. 29:09 I didn't draw the shaped. 1, 2, 3, 4. Touch your hero 109.5, okay? All equivalent all the same bond angles. 29:17 Yes? Let's look at these orbitals. I'm gonna just take these two orbitals. And not draw them all at the same time because that would be challenging. 29:25 There's a carbon nucleus. What is the shape of a P orbital? It's like the doll, like two. So it's like this one. 29:32 Okay. One. Here one here, that's a P. Yeah. How would this P be oriented relative to that? As an example. 29:41 Right on top of it? No. The P orbitals are along each axis, x, y, and z. 29:55 Remember? We did that? Here's a P orbital. Here's another P orbital. The third P orbital would be like that.. Okay, let's do these two. 30:07 These two? X, or z, or y? I can't hold y, like y, like that. Yes? Yes? Yes. This is one P. 30:18 This whole thing is one P. Yeah. So one, like, one, but it's not completely different. Two. Could be. Yeah. No problems, okay. 30:29 Yes? Are we with me? Yes. Okay. Hydrogen has its electron in a sphere. Here's a one S. There's hydrogen, sphere. 30:38 Okay? There's a nucleus, electrons whizzing around. It's got to come here to make a bond. So let's bring it closer. 30:45 There's a bond overlapping with that P. Yes? Here's another hydrogen coming in with its sphere overlapping here. We good? What's the bond angle? 30:56 Really? Cause that looks like a 90 to me. Oh, that was funny. Cause you guys switched it now. I'm so happy as well. 31:07 That's actually funny. P orbitals are at what angle to each other? 90. They are at 90. But you just told me that the angle has to be 109.5. 31:20 We have a problem. Houston, we have a problem. Can the existing P orbitals stay the same? No. We have to change this all up because it doesn't jibe with the way molecules form. 31:34 for. So S and P are atomic orbitals. What are those orbitals on atoms? To make bonds, we need a different kind of orbital. 31:47 What? Well, kind of, but we're not going to get there yet. So, because we don't do that, that's university. Okay, so. 31:59 It's related, but okay, so what is the tetrahedral geometry look like? So the tetrahedral looks like this, yes? I didn't make those big enough, yeah? 32:11 So if I said to you, draw a bubble around the region of space where I'm likely to find the electron. 32:17 Would you not draw a bubble there? That's got to be where the electrons are concentrated. Where would the next region of space bubble representing the region of space of where I'm likely to find the electron be? 32:28 Here, at 109.5 to that. Following? Where would the other one have to be? Here, sorry, I didn't mean to make that bigger. 32:35 here. Where would the other one have to be? So this is a new region of space. New region of space. 32:40 New region of space. New region of space. They're all the same. Equivalent regions of space on carbon. So do you know how you find a common denominator and math before you add fractions? 32:49 Common denominator? Same? We need to find a common denominator here in a way. We need to reconfigure. Imagine I had an S orbital shaped like a plate-o-ball. 33:01 And 3P orbitals, you know, plate-o-ball orbitals. Okay. Thank you. Imagine that? Smosh them all together. I have a big giant plate-o-ball. 33:10 I'm gonna recreate the orbitals and I'm gonna make them all the same. All the same. And they're gonna be at 109.5 degrees. 33:18 What will they look like this, Santa? Okay. See these? These are,... Hybrid orbitals. They are a blend of S and P. 33:41 What angle are they at? 109. So, look at the probability regions. Big probability region here. That's where the bond is gonna form as hydrogen comes in over there. 33:52 And opposite? What do you see there? A little tiny, tiny little probability region on the other side. Okay? Because a P orbital had a big lobe and another lobe. 34:02 But when we blend them, it concentrates the big lobe where we find the bond. And it still gives a little bit of a region of space on the other side. 34:08 Okay? And the same for all of these orbitals. So these are called hybrid orbitals. They're orbitals that we meet. We reconfigure the original atomic orbitals. 34:19 We redesign the region of space. Um, so that it matches what we know happens in molecules. When this hybrid orbital blends with hydrogen's atomic S orbital. 34:32 Hydrogen is the only element that does not need to hybridize. That's where we can, Configure its orbital. That's gonna be called a molecular orbital. 34:39 And you're gonna learn a little bit more about those in university. For now, we're, We just have to worry about these hybrid orbitals. 34:45 What do we call them? So, do you see how there's electrons in S and there's electrons in P, maybe not all the P for now, but, We're gonna hybridize how many S orbitals? 34:57 One. There's no such thing as two S orbitals. I listen to you right now, it's not supposed to be. Sorry. 35:05 Sorry. How many S orbitals? One. How many P at a? Two. Two. How do we write that? Sp two. Yeah? 35:16 Okay. That's what this diagram shows, but that's not actually gonna happen. Because we don't need, This would be three orbitals. 35:22 How many do we need? Yeah. So, we're actually gonna do sp three. This has to be sp three. Three plus one is four orbitals. 35:33 So, one, two, three, four regions. We'll you in the next is repelling. Need four hybrid orbitals. Esther's not convinced. She's like, what are you talking about? 35:45 Okay. So, if you go here, Oh, here. This is beautiful diagram. Okay. Watch this. We had two electrons in S and we had two electrons in P. 35:55 Yeah. We're gonna reconfigure them and blend them all together. And make them entirely equivalent. What tells you in this diagram that they're the same? 36:02 Do it again. Forgive you. Just look at the lines. That orbital, does it have a different energy than that one? 36:13 How about that one? How about that one? They're all now drawn at the same level. They are entirely equivalent in terms of energy. 36:20 They are degenerate. Yes? That region of space is the same as that one, which is the same as that one, which is the same as that one. 36:28 What are they called? SP3. Why? Because I blended three P orbitals and one S orbital. Okay? Okay. This one doesn't have an electron this do that. 36:38 How do I know to blend it? When you draw carbon, what did you tell, what do they teach you to do in, in grade nine? 36:44 North, south, east, west. That's got four automatically unpaired electrons. Look at this diagram. One, two, three, four. What up? Four unpaired electrons. 36:57 So you are putting an electron in each of a, uh, four equivalent SP3 hybrid orbitals. Okay? If you do this correctly, this diagram will match what's going s you already have been taught to do for bonding, okay? 37:09 And what do these lines represent? That region of space? That region of space? That region of space? That region of space? 37:16 What are they called? They're called SP3 regions of space. SP3 regions are at 109 degrees from each other. Can they deviate a little bit from 109.5 or 109? 37:27 Yeah. Yeah, a little. But they can turn into 120. They can become 107, like if this was a lone pair, okay? 37:34 I'll be with you in a minute... So, this is crazy. Watch this. It's so easy. Yeah. I'll fill in everything else in a second. 37:47 No. Watch this. It will come together in a minute. 38:05 Ellie, are you done? One. With your ranting, or whatever. Okay. The combination of orbitals we need to use to blend, to be able to get them into the regions of space that we find electrons at the right angles. 38:20 Our s, our p, and sometimes d. The exponents are not the number of electrons like they were before. They are the number of orbitals we are blending. 38:32 They will always add up to the number of electron pairs. This could be a b loan or bond makes no difference. 38:41 So if they add up to 2, what's the hybridization we would need? Sp. 1 plus 1 is 2. If they add up to 3, what's the hybridization that we will need? 38:53 Very good. If they add up to 4, what did we see? Good. Not d. Who said d? Do I see? 38:59 Oh sorry. 5. Why do we need to go to d now?. No more peace. 6. You got it. You don't need the one but you- yeah. 39:23 Oh I know cause we did it for- lecture conversion. Yeah. You're- you're- you're not done. We're gonna draw all of this story. 39:32 In- like, different ways. Okay. If you go back up, oh I realize we didn't figure- finish doing the polar thing. 39:42 Remember these shapes here? They're all polar. These are all polar cause they have long pairs. So polar, going down there, I forgot to fill that in. 39:54 Polar. Still polar. Still polar. So this whole page is polar. That's page 24. And then these two, this one's non-polar, the linear. 40:13 Polar. What about square planar? Lone, lone opposite, non. Yeah, lone pairs cancel, yeah. Okay, sorry, I forgot we didn't fill that in, so I'm just filling that in. 40:33 Everybody okay with that? Do we get that? Lone. Why is this non-polar? These are in symmetrical positions. Linear's are always non-polar. 40:48 As long as the atoms are the same here, Jalen. This atom matches that atom. Okay. See back over here. Let's go to this one, okay? 41:00 Everybody in this row, what's the hybridization? S.P. oh clearly. Okay, everybody in this row would be good. Doesn't matter whether it's loan or bond. 41:21 What's this row? So what are the angles between S.P.2 orbitals? Hybrid or S.P.2 hybrid orbitals? Are these guys? 120, okay? 41:35 So they have the greatest probability of the Good morning. P here, a little bit of probability on the other side. 41:39 S.P.2, S.P.2, S.P.2. Okay. The whole thing is S.P.2. Just like this whole thing is one P. Yeah? Okay. The angle could deviate a little bit from 120. 41:55 It could be, like, a little less, but 120 is the base for S.P.2. This is S.P.3D. These guys are S.P.3D.2. 42:03 You have S.P.3D. No. No. We don't have enough electrons for them. Oh, wait, we could have seven, I think. Yeah, yeah. 42:12 I won't do that. I'll be happy to get this. Like, really like Jacob? Everybody good? Okay, this has been filled in. 42:27 Okay, so let's come back here. All right. So what is this thing called hybridization? Hybridization is the reconfusion. Thank you. 42:37 In figuring or redefining of the regions of space that exist in atoms, which we call atomic orbitals, so they work to allow for proper bonding, which we call hybrid orbitals, in order to form the final molecule, which contains molecular orbitals. 42:54 There's more to say on molecular orbitals, but that will be said in university, I have to leave something for university. 43:02 That's when you learn about bonding and anti-bonding orbitals, like matter and antimatter. Alright, I'm okay. We'll a little bit the tape. 43:07 Okay, good. Okay. Hybrids are formed from sp and sometimes d. The bond angles and shapes that are predicted through vesper would not be obtained unless we redefined or reconfigured these regions of space. 43:20 Okay? And here's the other thing. How could you produce equivalent bonds if one of electrons isn't an s, or whatever the this diagram has, and these p's are oriented differently, how could they produce equivalent identical bonds that you can't distinguish? 43:36 If the electrons are different, indistinguishable orbitals in the first place can't happen. So we find, like, this common denominator, we reconfigure the regions of space in order to prepare for bonding. 43:47 It just redefines them. Okay? Hi. Yeah, except hydrogen doesn't. But we're gonna do them for all. Although I had a kid email me from McGill and he said that they're not hybridizing the other atoms they just showed for the center. 44:06 Cause that's the one that they should do. Okay, if it's based on, but I like to just do them all anyway. 44:09 I like it. But you might only need to do it in the center for the universe. Yeah, I can do it with that spirit. 44:14 You actually have to know it's not. Villains show electron pair repulsion theory, yes. Will I ask you the acronym? I haven't, yeah, but, yeah. 44:22 You just tell us you won't study all of the time. You should know, because the whole essence, it tells you that it's repulsion theory, like, then you know what it means. 44:30 You know what happened. Okay, draw an orbital box diagram. Do you guys want lines or boxes for your orbitals? So, I could d

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