 Okay, so I thought I'd just kind of bring up my laptop and show you what I see when I teach. Forgive the lag. Usually these seats are mostly occupied with students. It's kind of weird to be lecturing to a room without actual humans in it, well, other than me, if you can count me. Since I'm going to actually be doing demos today with chemicals, I'm wearing safety goggles. These are actually prescription goggles and bifocals at that. So, yay technology, and it is lovely being able to read the labels that are on the chemicals. So that'll just be parked to the side, and then you can see that it's actually me doing stuff. Okay, interesting for me, the YouTube in Second Life has frozen, but it is live on the website. So far so good. Thank you. Oh, thank you. Thank you, Chantal. I will be very happy to have that. Okay, let's see. Let me start now. So, going over here. That's my title slide. I did not get to have time to do much of a PowerPoint. I'm just going to delete stuff. And you know what? I usually steal stuff from like wiki pages and the like for illustration. So yeah, here's what like wiki has on chemical equilibria. I did not think that you would be particularly pleased at just seeing math, right? There's no pictures. The way this is taught is often through a lot of math and with not a lot of pictures. So that ends up being a problem. So while I am probably going to show you a tiny bit of math today. So sorry. The I'm going to try to draw things out for you and do a talk talk. Okay, so let's see. Bear with me because there's an aspect of clunkiness to this that is not fun. That figure. So that's where we are. So chemical equilibrium. What is a chemical equilibrium? Chemical equilibrium is a fundamental type of reaction. I'm going to give you an example. There is a chemical out there, vinegar. I think everyone's familiar with vinegar. It's actually acetic acid. And what I'm going to do is draw things out and then take pictures and post them to you. Acetic acid does this. Give me a second in water. Elite. Okay, so hopefully you can see what I've drawn here, which essentially has a structure of acetic acid that reacts with the water. And what happens is that a hydrogen atom just gets transferred. The left slide is cut off. What you can do if what you can do is click on the resize if you want. It should not be cut off in world because you're seeing exactly what I'm seeing. So basically, this is an example of a chemical equilibrium. What happens here is that this reaction does not go to completion. This reaction, let me draw. This reaction, that little set of arrows right there. Thank you, Chantel. It's looking like everyone sees their own view. I've got it set to 33% in my view. So if you click on 33%, or I can resize, we can get all on the same page. I thought we would be all seeing the same thing. All right. Okay, so I'm going to let you guys sort out your sizing options, which I guess are more individual than I thought they would be. And then we'll continue. So the idea here is that acetic acid, which is the CH3 double bond OH, can lose an H plus. It can lose the H, the H plus, which is located on that thing, and it can pop over onto a water. This reaction happens maybe in one in a hundred times. One in a hundred acetic acid molecules undergo this reaction. That's why we have this set of arrows here. It's not a forward facing arrow, which indicates that we would have just a one way reaction. This reaction can be reversed. The H plus can pop back onto this thing over here, which is called an acetate, and, you know, we make the starting terrorist. I'm going to draw an energy diagram. Give me one second, pump up, replace that image, buy a new one, make it bigger, and make it so that the 33% crowd would be able to see it. So essentially what I've got, essentially what I've got is two wells. This well right here, I guess that's not a good drawing. This well right here would be where the reactants would sit. You can just think of a little pool of molecules. I'll just kind of bop and along in there. They're always moving. They're always colliding. There's water. There's some acetic acid. It's always moving around. So what happens in these collisions? Is that up here? Sometimes on this side. Sometimes on that side. Just from the randomness of your collisions, there's enough energy to make a hydrogen pop onto a water. Well, that energy transfer corresponds to hiking up this little hill, and then being in this little well, little shallower well. And I can tell that this well is a little shallower, and it's got from the perspective of this well going over to the starting materials is a lot easier because it takes a lot of less energy. So this well is going to be less occupied. This one is going to be an endothermic. Yes, it does require energy to make this happen. There are things that we can do. We can basically make some labels here. We draw something. When I draw something with a pen, it's permanent. It looks better. And I'm not going to use the standard chemical notation. I'm just going to use an activation energy and a energy change. There we go. Okay. I'll get rid of that. So basically, it takes to go from the starting materials over here to get into the well on, to get into the well on, there we go. It's somewhat hard to move things around. On the right, you can see that it takes quite a bit of energy. To go back, it takes much less energy. It really only takes, let's see if I can make the box the right size. It really only takes the height of that box to go back. Equilibrium is all about energy differences. We can we can actually predict how fast these reactions are going to happen from the heights of these barriers. I wanted to do just the tiniest bit of math at you. So sorry. I'm just going to write down an equation. Generally accepted equation is that rate is equal to some constant times the concentrations of everything you've got present. So I'm going to keep that picture and move it off to one side, but give you a different picture instead. Okay, so sorry for the math. But how fast the reaction goes? And you'd say, well, that'd be in concentration per second. How the concentration changes every second is going to be dependent on like your concentrations. So the square brackets around some symbol means concentrations. So I put HA as the acetic acid and I'm going to put the water in there as well because the acetic acid and the water have to bump into each other. They're going to bump into each other every once in a while. And collisions are how chemical reactions happen. Not every chemical reaction results in a collision or not every collision results in the chemical reaction. So sorry. So that's why we have a constant here in the front that basically tells you that not every reaction is going to result in or not every collision going to result in a reaction. Now, we can do things. We can do things like consider. We can consider this picture again over here. And we can figure that there's going to be a forward reaction. Oh, my pointer is actually kind of live. And a reverse reaction. Okay, so maybe what I can do is actually write down the rate equations for the forward and reverse. I'm going to put the, I'm going to make the constant for the forward into a kf. Rate equals and k reverse. I'll call it kr. And then I wonder the products again. We are looking at H3O plus and acetate. Right. So, bam, let's do that. And control V. And I want to thank everyone for your patience with me on this. This is brand new. So here's the thing. The rate of going forward, that's this top one up here, would be constant times the concentrations of those two things, the things that have to collide to make the reaction go. The rate of going backward is a different constant times the products of the reaction. What I've got up here. I'm calling A minus this CH3CO minus. Easier to draw. Now, at equilibrium, it looks like nothing is going on. Looks like nothing is going on at equilibrium. But the thing is that there's a left going on. The thing is that the forward reaction is happening at an equal rate to the reverse reaction. So it looks like nothing is going on because the concentrations are always the same. Right. But it's not always the same molecules in the same states. Think of hockey, for example. There's six people on the ice, you know, 16 members on the ice. But it's not always the same 16 members. But think about going to McDonald's. Right. So maybe there's like three people in front of you in line. Right. Well, someone gets served and they get out of line, but someone comes in and lines up behind you. Well, that line still has you and three other people in it. So equilibrium is always about, is always about forward reactions and reverse reactions happening at the same rate. And we can continue into math. I mean, here's the thing. If we take those two equations and make them equal to each other, what we can do is put concentrations on one side and constants on another side. Let me do that real fast for you or at you as the case may be. K forward over K reverse will end up being concentration H3O plus concentration of A minus all over. H2O and I'm kind of doing this kind of sloppy, but that's okay. Okay. Interesting. I had wrong window when I recorded function. Okay. So here you see constants on one side and then concentrations on the other. And it's basically the concentrations of all the products up top concentrations of all the starting materials on the bottom and that ends up that ratio of concentrations ends up being a constant. That constant is called the equilibrium constant. We just call it K, big K. This is one way of achieving a big K. There's some things that other chemists might criticize for me, but I think for an audience saying, hey, how fast the reaction goes forward, how fast the reaction goes backwards, and this tiny amount of math gets you something that's actually a fundamental thing in chemistry. These reactions can happen very fast. The forward reaction and the backward reaction goes very, very, very fast. It's all related to the height of the barrier. In fact, each individual KF or KR can be related to the height of the barrier. There's an exponential relationship there. I'm not going to be evil at you with this. But essentially we can have all sorts of reactions that happen. Let's see. I think it's time for a demo. So what I'm going to do is actually tell you what I'm going to do. There's something funny about that statement, but I can't quite put my finger on it. Let's see. I think I'm going to do the cobalt demo first. Let me write down what happens here. We've got a blue form and a pink form. I hope I brought the right chemical with me. Oh, I brought cobalt 2 acetate. We'll try it with this. I don't think it's the right stuff. Barn cobalt 2 acetate. Essentially what I'm hoping for is that we have cobalts with waters attached to it as one form. I think that's the pink form. When I dissolve it in ethanol, there's another form of it. Let me just copy that for you. Okay. So basically there's a cobalt form. Actually I think it's supposed to be 3 plus. I got the 2 plus. We'll see if it works. Then there's another form which is actually a cobalt. Usually it's a tetrachloride when you do this. But we'll see what happens. Okay. So I'm going to go over the live stream. There is lag in the live stream. Okay. So let's see. Let's see. I've got my cobalt acetate. I'm going to take a little bit and pop it into a test tube. And I'm thinking if this is going to work when I dissolve it in ethanol, ethyl alcohol, it's not like gin or anything like that. We're not allowed to have that on campus. Plus it's distilled from benzene to make it drier. You would not want to be having this like cancer tonic. So ethanol. And then, oh man, okay. That's terrible. Okay. So yeah, I brought the wrong chemical. Not a bad thing anyway because I brought lots of other chemicals. And it's actually not dissolving all that well. Full of tell. Let's throw something else in there. There's ways around. There's ways around this. I know the blue form is when you've got lots of chloride present. I'm not sure if this is going to work. Still not. A little ladder to actually make it dissolve. It's like cooking with Julia. All right. Well, every demo you do, you have to make a sacrifice to the chemistry gods, be it a demo that doesn't work or a finger. So I still have all my fingers. So here's the demo that doesn't work. Guess what? We'll do the demos I tried. There's all sorts of equilibria. You can have an equilibria set up just when you dissolve something. Okay. So for example, one that I'm going to show you involves silver chloride as a solid. And when it dissolves, it breaks up into individual fragments like a silver plus. And I'm just going to put an AQ and a chloride minus AQ. And let's get that in front of you. Put it on my windows. Let's see how many things go away. Delete. Delete. Delete. Control V. So here's an example of an equilibrium. All right. One aspect of equilibria is that they, I've mixed randomly more chemicals than I want to think about. I'm again surprised that I have all my fingers. And that's, yeah, that's scary. So coming back, let's think about the silver chloride. So when you have silver chloride sitting in solution, it just looks like some white powder sitting under a solution of like clear liquid. But here's the thing. There's always some of the silver chloride dissolving. And there's some of it reprecipitating. The rates are equal. So it looks like nothing has happened. Okay. But an equilibrium is a live reaction. Let's say, let's say that you did something. That's weird. I need a bit more experience. Let's say that you did something that made some of the silver go away or turned it into something else. That would cause this equilibrium to react by making more silver chloride dissolve. So the concentration of silver is in accord with our equilibrium constant equation. All right. So let me show you some reactions here. I have a molecule. It's called, if you can see this, it is silver hexafluorophosphate. So AG, and then AG plus has to have an anion. The anion is PF6 minus. This stuff is not terribly soluble in water. And it's also something that has kind of gone bad for the uses I would use it for. So we're going to use it for demos. It's a gray powder. Let's pop it in. Oops. I want to slap it around too much. You'll see me struggle to keep finding the lid. Gray powder. It's supposed to be a white powder. It's gray. That's why I don't trust it for the student's research. I've got water. We're going to try to dissolve it. And you can see I get a cloudy solution. Some of it dissolves. Okay. So this is the same sort of thing. AG PF6 tries to break up and turns into AG plus and PF6 minus in solution. But it's not quite there yet. I can make the rest of the AG PF6 dissolved by turning whatever silver has dissolved into something else. So let's use concentrated ammonia. This is just a water solution into which as much ammonia has been dissolved as can possibly dissolve. This has quite the odor. One thing in second life you're not getting is just the pungent odor of this. And I'm going to try not to spill any. All right. So I'm going to just move my laptop just a little bit here so that I can do this over a sink. There we go. Do this over a sink. I'm just going to pull a little bit right out of the bottle. Now that clears your sinuses and I'm going to put the lid back on. Oh my God. And now let's see. Okay. There we go. So as I add some of this stuff, you can see cloudiness goes away. I'll just add a little bit more. Oops. All of it went in. That's okay. Okay. So I got my silver to dissolve. What if I didn't want my silver to dissolve, right? Well, I chose AG PF6 because it was a little bit soluble to begin with, but not terribly. I could pull the rest of it into solution by adding some ammonia. You actually make a silver with two ammonias attached, but you could add chloride. And if you add chloride, what happens is that the reaction on the screen, this thing over here, well, if I didn't have any chloride to begin with, an equilibrium reacts to kind of push back against you. If I didn't have any chloride to begin with, the reaction would go towards the left, the form silver chloride trying to get rid of some of the stuff. Fair enough. So let's add some chloride. Okay. I'm going to put this thing down for one second. There we go. I actually have a rack of test tubes here. I'm going to make up fresh test tube. I've got potassium chloride. I'm hoping the lag isn't a deal breaker for us. I'm just going to scoop some out with a clean spatula because these are research chemicals, and I kind of want to keep them clean. I don't want much, just a little bit. Okay. So a little bit of potassium chloride. This will dissolve in water, give you K plus ions and Cl minus ions. Kind of funny, the doors keep opening and people keep popping their heads in. It would be welcome. We have a Boy Scout event happening today. I did not know that was happening. Otherwise, I would have had them come too. Okay. Silver over here, chloride over here, and if we're lucky and have been good, we don't get anything happening. Oh, look, there's just a little bit of cloudiness. Big bucks, no Emmys. Okay. I was a little too conservative with that, but you can see some cloudiness. Some solid is trying to form. Okay. We can be, you know, being careful is not a bad thing because then that means we can continue to add a bit more chloride and see what happens. I'm hoping you don't mind some of my meanderings here. Okay. Dissolving, that's a more concentrated solution. It's got more of the chloride in. Bam, bam, bam. And mixing it so you can see. There we go. Okay. So now you can see the cloudiness and we've definitely got chloride back. Okay. Chloride doesn't compete so well with ammonia though. And I can make this go away. This is me manipulating this equilibrium so that we can, you know, force it to go favor the left or force it to favor the right. And back with the ammonia. Smells lovely. Now let's see what happens to our cloudy solution as I add a little bit of ammonia. Oh, look, I made the silver chloride go away. Okay. So what we can do is manipulate equilibrium. They're live reactions. They're always happening. If it were dead reactions that just went and stopped, then nothing we did would make any difference to this stuff. Okay. So I got one more part of this demo. Hopefully everyone's doing okay. All right. One more part of this demo. I've got the ba, ba, ba, ba, ba. Okay. So this is potassium bromide. Turns out that bromide will also bind to silver to make a solid, but it binds more strongly than chloride does. It can out compete both the chloride and the ammonia. So what I'm going to do is show you what happens when we add some potassium bromide to this solution. All right. Obviously we're going to get a solid. That solid I can add as much ammonia to it as I want. And it's not going to re-dissolve. Okay. KBR, pirate's favorite chemical, right? KBR. Next to R. Okay, dissolved. Here's our silver solution. Plus everything else. Putting KBR back in there. Yeah. Nothing subtle about the formation of that precipitate. And opening up the, opening up the, let's actually put this thing down back in the rack. So I'm not like pouring it on myself. Okay. So back with the ammonia. You can see all of that. It won't be subtle. That's the first addition. I'll do three additions. Always before we were able to get everything to dissolve pretty easily. Nothing. Again, I'm hoping to lag on this. Three additions of concentrated ammonia. This is smelling lovely. Sounds like the litter box. Is that a forecast? Anyway, there's no re-dissolving. Okay. But we can manipulate equilibria quite, quite readily. You know, let's come back to this thing. This thing has acetate and water attached to it, but Cobalt kind of likes to have ammonia attached to it. I mean, let's just see what happens here. This is not planned. This is extemporaneous. This is going to happen in the waste container anyway. So why not see what happens here. Back to our Cobalt. What would happen probably is that my prediction would probably be that we would have a color change as things that are attached to the Cobalt swap out for ammonia. Oh, look at that. The color change I was hoping for has happened. Okay. So we've got Cobalt swapped out for ammonia and it's another equilibrium. This is another live reaction. If I ended, if I got rid of the ammonia by adding some acid, I brought glacial acetic acid. It does not come from a glacier. Okay. It's basically 100% acetic acid vinegar is like four and a half to 5% acetic acid. So this is glacial. It's 100%. Let's see what happens. It might be enough to neutralize the ammonia and get back. This is also smelling lovely. Oh boy. And get us back to our pink form of Cobalt. Okay. Sorry, while I'm paying attention to the live stream, I'm not paying as much attention. Oh, look at that. We've got some news happening. That's probably ammonium acetate. And then as I shake this, the color is less intense than it was. Just a few more drops. And we have the obligatory fumes for a chemistry demonstration. And yes, I still have my fingers. And we've gone pink and blue. So bone chemical. But if you know the chemistry, adding ammonia will turn it into a Cobalt ammonia complex that has a different color. neutralizing the ammonia gets you back to the starting material. Alrighty. Hey guys, you're welcome in here. I'm given a live presentation though. So I actually liked that last one. The pink and the blue kind of showed you a little bit about what was going on here because but I mean the ammonia silver complex has no color. Okay, I'm going to hop back over onto the computer here and kind of see how how people how people are are doing so far so good. Is everyone all right over in over in second life? Hey, let's see. So neuro is actually what we're doing is looking at proton transfer. We didn't do any electron transfer reactions. Those are a completely different top. No, they're not a completely different top at all. But it's follows up on on this particular top. So, you know, I'm going to wrap up just because I see the time is getting towards the 1pm and I have a history of going on way too long. So the idea of chemical equilibrium is one where I'm going to bring this energy diagram back up. Function of control V. And yes, okay, that's my second life. Always have to make sure you're on the right screen when you do a screen copy. Okay, so wrapping up coming back to the idea of chemical equilibrium. You've got chemicals. They can react with each other. But they don't have to react 100%. There could be a stable state where most of them are present the starting material. There could be an energy barrier they have to surmount. And they get that energy to surmount the energy barrier just from the random collisions that are always happening. And then they can spend some time over here before random collisions send them back. On average, at the end of a chemical reaction, these transformations are still occurring. They're going forward and backward. Then they can be occurring at a tremendous rate, trillions of times per second. It looks like nothing's happening. But when you disturb the equilibrium in some way, as we were doing with the silver by changing the amount of silver that was present, what happens is that we can really see these reactions are live. It's all a consequence of the conservation of energy. When you have a ball rolling down a hill, friction slows down the ball and the ball stops. The energy is not gone. It has turned into heat. And that heat is still present as motion, as motion of molecules. Those molecules never stop moving. And that's what enables these equilibrium to happen. Okay, so that's where I am. There's a lot more of the chemical equilibrium we teach. Oh, it's eight weeks in our second semester freshman chemistry on equilibrium. There's a huge amount that we teach on it. But you don't need to be able to do all the math just from this casual set of demos. I hope the lag in the livestream wasn't terrible for you. But I'm happy with your feedback and we can see what improvements we can make in doing these sorts of things. In the future, I'll actually have slides prepared so that we can not do this whiteboard thing in this way, I think. All right. Thanks so much, everyone. Let's see. Sizi, thank you. All right. I thank you for all of your attention here and patience with me. Just the past few weeks, I've just been very busy. I'm teaching an overload, so it's four classes, equivalent instead of three. I'm a constituency head, chair of our graduate council on campus. So there's a lot of meetings like board of trustees and stuff. I've started a new business. So it's been it's been a busy time for me. Okay. Sizi, I think I will do this again. I really like the idea of doing demos for you guys, because we got a lot of stuff. I can really show a lot of different chemicals. These are the ones I can put together in five minutes. With more preparation for things, I can really show you some cool stuff. Awesome. You know, if anyone wants to do this kind of thing as well, I'll be happy to kind of rock them through how to set up. I mean, essentially setting up a live stream is not on YouTube is not a big deal. All I've done is created an object, selected the side, and chose a texture that's media and popped in the URL. Any question? I still had all my fingers. I should do a live stream on how to do a live stream. That's, you know, that's actually kind of weird. Kind of a thing that's fun. You know, one of the things that I have to do when I teach, I have, I teach a course for an instrument called a nuclear magnetic resonance spectrometer, and the troubleshooting involves shutting things down and turning them back on. But trying to do a zoom recording of the process of shutting the computer down on which the zoom recording is occurring often doesn't get recorded. I'm more than happy to, more than happy actually to show you people how to make objects in second life and port objects from the thingiverse, you know, takes a little bit of time and blender to clean sometimes up and otherwise. Yeah. Alrighty. So with that, what I think I'll do is close down my live stream, stop confusing the poor little nine year olds who keep coming in and wondering what's going on and, you know, let everyone have their day back. So thank you all very much. And, you know, basically, thank you very much. I had a colleague who was really interested in how this would go. So having a recording would be on. At this point, I'm going to not even say these objects because it's just a panel with a texture. Stand. And.