00:00:00 During the study period the room will be open also. Only on Tuesday and Wednesday will there

00:00:11 be teaching assistants there to answer your questions. So on Monday and Thursday the room

00:00:16 will be open for you if you want to use any of the resources there or if you want to check

00:00:20 some lecture notes and so on. The other announcement has to do with the fourth hour examination.

00:00:31 Some people are a little bit disturbed that they didn't do as well on the fourth hour

00:00:36 exam as they had expected to. I'd like to mention again something that I mentioned at

00:00:41 the beginning of the course. The one thing that we will take into strong consideration

00:00:45 at the end of the semester is how well you progress throughout the semester. And if you've

00:00:56 had a bad exam, if you've had one bad day and everybody is entitled to at least one

00:01:00 bad day, as you will shortly see, we will look at the final examination portion that

00:01:10 covers the hour exam in question. That's the one that you didn't do so well on. And see

00:01:14 if you've improved then. We'll take that into strong consideration. I also want to remind

00:01:21 you that there will be a Chem Tips message for every one of you in the Chem Tips box

00:01:27 first thing in the morning. So it tells you about all these announcements that I'm making

00:01:32 and also tells you about the final exam room, which is room 3650 in the Humanities Building.

00:01:39 And the exam is a week from tomorrow at five o'clock. Now usually the last lecture of the

00:01:47 semester we set aside for doing a series of demonstrations that students have responded

00:01:55 favorably to. And I want to make an exception to what I normally say in my lectures. I usually

00:02:05 say that everything we talk about will appear on the examination. Well, this lecture is

00:02:10 an exception. And so what I'd like you to do is put your notebooks away and sit back

00:02:15 and try to follow what we're doing here. Now we've talked throughout the semester, throughout

00:02:25 the semester we've talked about a variety of topics. The last one that we talked about

00:02:29 is chemical equilibrium. I'd like to go through a series of colorful demonstrations to show

00:02:35 you how the position of equilibrium can be changed by simply changing the concentration

00:02:42 or by adding an appropriate solution to another one. And the best thing that you can do perhaps

00:02:49 is to see these changes is to look on the monitor because I'm going to do them in these

00:02:55 relatively small beakers here. I'm going to start out with some water in this beaker. I'm going to

00:03:01 add to it some solid ferric nitrate. And the color that develops here is the color of the ferric ion

00:03:10 which has some water molecules attached to it. It's the color of the aqueous ferric ion. Now by

00:03:20 changing the concentrations, you can see that the representation of what I've done here is a

00:03:26 reaction between solid ferric nitrate, adding water to it to get this ion here, the Fe with H2O

00:03:33 taken five times and one hydroxide in it. And this ion is the ion whose color you see here. Now by

00:03:40 changing the conditions of the reaction, what I've done here, I have a series of beakers that contain

00:03:48 solutions of the aqueous ferric ion. I'm going to add some acid to this. And as I add the acid,

00:04:00 another reaction takes place. And what I've done is simply take the complex ion here, add hydrogen

00:04:08 ions to it, and simply add a proton to the hydroxide ion to end up with a new ion which has, in this

00:04:14 case, no color. That is, it doesn't exhibit absorption spectra in the visible region. So what

00:04:22 I'm going to do is work with this ion, add a variety of substances and see what kinds of changes

00:04:25 take place. The next thing that I want to do is add a chloride ion. And this is in the form of

00:04:35 sodium chloride. And you'll see that the characteristic color of this ion doesn't differ

00:04:48 too much from the original color of the aqueous ferric ion. So the ion whose formula you see

00:04:57 on the screen there has the same color as the original color. Now I'm going to add

00:05:04 another substance, which is phosphoric acid. And again, we see that the phosphoric acid

00:05:16 reacts with the ferric ion in a special way to give us a new ion. And this ion happens to be

00:05:24 colorless. Now we're going to take the same

00:05:27 solution and add to it still a different substance, which is potassium thiocyanate.

00:05:36 And we'll see that the color of the potassium thiocyanate

00:05:46 is this deep blood color here. And again, we have an ion that has its own characteristic color.

00:05:53 All we're doing really is changing the position of the equilibrium between

00:05:56 these various ions whose formulas you see and the aqueous ferric ion.

00:06:02 And let's do just a couple more here.

00:06:14 I'm adding fluoride ion now in the form of sodium fluoride.

00:06:17 Quite a bit of it. I guess maybe I added a little bit too much.

00:06:24 I guess I didn't add enough. The fluoride ion then forms a complex with iron and we get this

00:06:35 new ion that has again this colorless property. Now the substance that all of us use sometimes

00:06:44 is a common substance. That's ink. And ink is nothing but a mixture of

00:06:50 this iron 3, aqueous iron 3 ion with another

00:06:58 mixture, another ion that contains iron. And the formula of the major component of ink that has

00:07:06 this, the blue ink that is, is the one that you see here. So we can take this iron 3 complex

00:07:12 and change the position of equilibrium by simply adding these various ligands.

00:07:18 Now what I'd like to also do, and I should have put my glasses on before,

00:07:23 is demonstrate some of the properties of air. You know, air is a mixture of nitrogen, oxygen,

00:07:32 mostly nitrogen, oxygen, some carbon dioxide, and a few rare gases. And what I'd like to do

00:07:38 for the remainder of the lecture is to talk about and demonstrate the properties of air

00:07:45 in a variety of ways, as you'll see here. What I have here is a can that is being heated to

00:07:52 drive the air out of it. What I'm going to do, let's just let it heat for a second,

00:07:57 is demonstrate Boyle's law to you in a slightly different form than the one that we've talked

00:08:03 about before. There's a little water in there. We're evaporating the water to drive off the air,

00:08:11 pretty much the same kind of experiment that you did in the lab when you determined the

00:08:15 grand molecular weight of a volatile liquid. Well, as the air is driven off, what I'm going to do now

00:08:22 is stopper it, and then try to cool it by putting it into this ice mixture here,

00:08:35 ice water mixture, and see what happens to it. This has got to be a little bit tight,

00:08:44 and we'll just let that go for a while. All right. Hello.

00:08:49 What you see is happening is that the can is, see in here, I guess, is making a lot of noises.

00:08:59 The can is collapsing because the pressure outside is greater than the pressure inside, and this is

00:09:09 another example of the pressure relationships that we've talked about. It's a little bit hot.

00:09:16 You know, this illustrates Boyle's law in a slightly different fashion than the one we've

00:09:21 talked about before. You know, this illustrates that the greater the pressure, the greater the

00:09:27 volume of hot air, and as this hot air cools down, maybe this will help it along.

00:09:38 Well, we'll just let that go for a while now and see what happens to it.

00:09:48 Oh, it's happening. All right. That's good. Good. Okay. Well, the two major components of air are

00:09:55 oxygen and nitrogen. 20% of air is oxygen, and about 79% is nitrogen, and I'd like to sort of

00:10:04 have you keep in mind that the boiling point of oxygen is minus 183 degrees centigrade,

00:10:15 and the boiling point of nitrogen is minus 196 degrees C, and so what we're going to do is really

00:10:27 talk about the properties of gaseous oxygen, gaseous nitrogen, and also about

00:10:33 the properties of liquid air and the properties of liquid nitrogen and liquid oxygen. The other

00:10:39 component of, semi-major component of air is carbon dioxide, and carbon dioxide has a lot of

00:10:48 properties that we've examined, but it has one other property that I'd like to demonstrate to you.

00:10:56 That is the reaction between carbon dioxide and calcium hydroxide, and if you look up

00:11:09 on a chart, you'll see that I have a reaction there represented by two equations,

00:11:18 and what I'm going to do is try to have this solution of calcium hydroxide react with some

00:11:31 carbon dioxide, and to do this, I'm going to have to get two volunteers from the

00:11:39 audience here to supply me with the carbon dioxide, and

00:11:48 so I guess I'm going to call on you. Could you stand up here so everybody can see,

00:11:54 and if you just look at that camera over there and blow into it, okay, just look over there,

00:12:01 okay, and I'm going to try to ask you to come over here, and we're going to have a, wait a minute,

00:12:07 wait a minute, we're going to have a contest to see who's going to give us the most calcium

00:12:11 carbonate, so you look at that camera up there, and when I say go, you start blowing, okay, ready,

00:12:17 go, don't forget to blow, don't, make sure you don't suck this stuff in there, okay,

00:12:23 now what I'm going to do as we're having this little race,

00:12:29 see, the more you laugh, the more chances you have of losing, so

00:12:34 what I'm going to do is have my own supply of carbon dioxide, and I'm going to, one of the

00:12:41 solutions is getting to be cloudy, and so is the other one, and what I'm going to do, I'm going to

00:12:47 beat both of you by taking this, now you just look at the camera, by dropping a chunk of dry ice in

00:12:55 there, and pretty soon, fairly soon, in fact, you see I have a cloudy situation developing here,

00:13:02 fairly cloudy, and the point is that their lungs do not supply as much carbon dioxide as can be

00:13:08 supplied from, by means of the chunk of dry ice, how are we doing, oh that's pretty good, thank you

00:13:14 very much, thank you, I'd call it a draw, wouldn't you, okay, thank you, now what I'd like you to do is to

00:13:24 watch this setup here, and look clearly to what's happening to the solution, the calcium carbonate,

00:13:33 which is the insoluble substance, is becoming soluble, in fact, if I help this along a little bit

00:13:41 by adding another chunk of dry ice, which is a source of carbon dioxide, you see that we have a

00:13:47 means of dissolving the limestone, and the reaction that we're talking about is the one represented on

00:13:53 the chart there, but the reaction between calcium carbonate, carbon dioxide, and the water, which

00:13:59 forms a soluble salt, calcium bicarbonate, so again, this is an example of how you can shift the

00:14:04 position of equilibrium by simply controlling the reaction conditions, now it would have taken them

00:14:10 about two hours to supply enough carbon dioxide to get all the calcium carbonate to dissolve,

00:14:17 and I think they have better things to do, okay, now in looking at the other components of

00:14:28 of air, where we've looked at carbon dioxide, we're going to look at liquid nitrogen and

00:14:32 liquid oxygen, and again, we're going to look at helium, which is a very, very rare gas, and

00:14:41 is present in small amounts in the atmosphere, and so in talking about

00:14:49 liquid nitrogen, we're talking about liquefying air and getting the nitrogen and oxygen separated

00:14:57 from each other, and this can be done by a variety of means, one by taking advantage, for example,

00:15:04 the difference is in the boiling point, we can liquefy air and take advantage of that and have

00:15:10 some liquid nitrogen, and let's see if we have some liquid nitrogen here, I'd like to see how is

00:15:16 the can doing here, the can doesn't look too good, and so what I'd like to do is get this can out of

00:15:26 the way, you say over here,

00:15:40 that's so funny, are you watching yourself, I see, it's a funny experience, I know it,

00:15:45 see, my lab technique isn't so good,

00:16:00 okay, okay, well, we're going to go from one liquid to another, and we're going to go from

00:16:08 liquid water, nice, to some liquid nitrogen, and here's some liquid nitrogen, you see it's a

00:16:13 very good liquid that can be used very efficiently for removing dust, because

00:16:22 because once it collects the dust in one area, then it evaporates and is converted to

00:16:29 the gaseous state, and we don't have to worry about it, and somebody has to go

00:16:33 and pick up the dust, it's getting a little bit wet here,

00:16:37 oh, all my notes are, okay, so what we're going to do now is show you that we can use

00:16:50 liquid nitrogen for a variety of purposes, one of them is to cook in it, and I'm going to put some

00:16:57 liquid nitrogen in the coffee can, I'm running out of liquid nitrogen here, so let's get a little more,

00:17:07 and since liquid nitrogen is at a very low temperature, in fact, its boiling point is minus

00:17:12 196 degrees, I'm going to heat up the liquid nitrogen by means of this ice water mixture,

00:17:20 and let's see if that will work, we'll get to see, it's boiling already, you can see that

00:17:29 you can see that the cold ice water mixture is supplying heat to the much colder liquid nitrogen,

00:17:42 that's a very different way for us to think about boiling, but that's what's happening,

00:17:48 the heat coming from the ice is causing the liquid nitrogen to boil, so in terms of

00:17:56 readjusting our temperature scales and our way of thinking about heat and absence of heat,

00:18:04 you can see that it requires a change in it, so I'm going to save this liquid nitrogen

00:18:09 because I want to use it for a different purpose, oops, okay, so what we can do,

00:18:20 I won't do anything to you, it's just very cold, you can just pour it on your hand like this and

00:18:24 make sure you don't cup your hand because then you'll get a burn, which is what I just did,

00:18:33 so, okay, so one of the questions is, okay, if it's so cold, you know, how do we keep it,

00:18:43 where do we keep it, well, we keep it in these thermos bottles, you know, they're insulated and

00:18:48 except that scientists have a fancy name for these thermos bottles, they call them

00:18:53 Dewar flasks, and so we're going to be keeping the liquid nitrogen in the Dewar flask

00:18:58 and working with it, it's really pretty wet down here,

00:19:08 okay, well, let me just do something else here,

00:19:13 let's go back to our liquid nitrogen here, let's just add a little more,

00:19:26 and now, instead of supplying heat from this ice mixture, let's just really heat the hell out of it

00:19:34 and really get it to boil, you see it's boiling all over the place, but you also see that something

00:19:39 else is happening to it, in terms of it's turning color, now let's just see what's happening here,

00:19:54 can't make up my mind whether it's too hot or too cold, okay, if you look at the bottom of this,

00:19:59 you'll see some white material there, and I want to see if you can figure out what this material is,

00:20:08 does anyone have any ideas, huh, what, somebody says it's CO2 or water, well,

00:20:15 water, where did the water come from, from the frozen air, frozen air is on the inside,

00:20:24 what's that, from the, that's right, we're burning methane, natural gas here,

00:20:30 and the product of the combustion reaction are CO2 and H2O, and so we're getting a mixture of

00:20:36 frozen moisture here and some solid carbon dioxide or dry ice, and in fact, this is a good way

00:20:44 of making carbon dioxide, it's not a very good way, because you have to use liquid nitrogen,

00:20:49 which is much more expensive than carbon dioxide, so we'll just let that

00:20:54 go for a while, and move on to talk about the properties of other substances

00:21:04 in liquid nitrogen, and one of the substances we want to talk about is natural gas, and what I have

00:21:10 here is a door flask containing some, oops, come prepared, right, what I have here is this liquid,

00:21:31 uh, hello, let's cool it off again, I guess I warmed it up too much, what I have

00:21:44 is a liquid form of methane, now the boiling point of methane, CH4, has a boiling point of

00:21:53 minus 126 degrees, and you see it's a higher boiling point than liquid nitrogen, so we can

00:22:00 then liquefy gaseous methane and have it in a liquid form, and who did it?

00:22:14 I guess I did it.

00:22:19 It's still in there.

00:22:20 What? It's off again. Oh, I see the glass stuck to it.

00:22:39 Yeah, it's still in there, what I'm looking for is another, uh, oh here we are, another door flask.

00:22:46 Wonderful.

00:22:55 Again, wonderful.

00:23:06 I keep telling you my technique is sloppy, but,

00:23:09 okay, let's see what happens now if we put it over here, I already saw what happened there.

00:23:27 And the freezing point of methane is below minus 196, that's why it doesn't freeze,

00:23:32 so now we can get this out of the way and see what happens with our methane.

00:23:41 And what we're going to do is try to use this methane as a source of fuel,

00:23:49 and let's see what happens. We've already had one disaster.

00:24:02 And what I have, you see up on top here, is a nozzle out of which the methane is going to be

00:24:08 coming out in the gaseous form. We already know what the properties of methane are. Now the thing

00:24:17 to remember here is that we have a very high concentration of methane, there we go,

00:24:24 see the flame, you see the flame?

00:24:34 It's coming out so fast that it's putting out the flame, freeze a little bit,

00:24:39 cool it in other words.

00:24:43 Okay, let's try it again.

00:24:48 Hello, can you see it?

00:25:09 Just dump it out. I guess we're lucky we didn't have a fire because with that

00:25:14 all that concentration of methane down there we could have had a slight problem.

00:25:22 Okay, well what I also want to do now is look at another fuel which is kerosene, and I'm going to

00:25:33 make, you think I'm crazy don't you?

00:25:44 Okay, I'm going to put some kerosene in here.

00:25:54 Okay, and then I'm going to let it sit in this liquid nitrogen

00:25:59 and do it for a while. I'm also going to take a little bit of

00:26:09 everybody's favorite compound which is ethyl alcohol,

00:26:15 and you know ethyl alcohol has a lot of uses. It's used as antifreeze.

00:26:20 I see I don't have to tell you what else it's used for.

00:26:30 Okay, I'll get rid of some of these things here, and oh what did I do with the ethyl alcohol? I

00:26:38 didn't put it in place. Thank you. Okay, let's get a little more nitrogen here.

00:26:51 I don't have very good aim, do I?

00:27:07 Okay, and

00:27:12 just let this freeze in here for a while.

00:27:14 Actually, we have a little too much in there.

00:27:19 Well, we'll let those go for a while and see what happens.

00:27:26 So, we'll come back to them in a little while and see what happens to them. Now,

00:27:32 I'm going to look at some other substances that I have here. I have this rubber ball,

00:27:37 and just to verify that it is a rubber ball, why don't you...

00:27:42 I don't think we want to sign it. We can't catch it.

00:27:46 Yeah, watch this. Watch this.

00:28:04 You got a basket.

00:28:06 Got a basket. Okay, so what we're going to do is take this rubber ball,

00:28:12 and we have another rubber ball here too, and we're going to add a little liquid nitrogen to it and

00:28:16 see what happens. And we're also going to take these small pieces of rubber that you see here,

00:28:27 and we're going to freeze those too by...

00:28:30 Oops, I keep forgetting.

00:28:40 Just give it a little more. It's kind of thirsty there. And see what happens. Get in there.

00:29:00 There we go.

00:29:08 I can't get it out. Oops.

00:29:16 Okay, well, let's see if we can get it out. There we go.

00:29:20 You see, it still looks the same, except that its properties are quite different now.

00:29:25 You're seeing it...

00:29:34 What we've had there really is a shattering experience, you know.

00:29:42 Okay, let's see what's happening to these other guys down here.

00:29:48 Where did I put mine? There they are.

00:29:55 What the hell with them. I'll just get them out. See, they're pretty hard too.

00:29:59 And what I'm going to try to do now is use this hammer to drive

00:30:10 the nails, which I have just made, these rubber nails.

00:30:20 There we go.

00:30:21 We have some of these rubber nails. Drive them in here by means of this

00:30:30 mercury hammer. What I've done here is freeze some mercury in this form. Let's see how well it works.

00:30:38 I hope nobody reports me because I don't belong to a union. Whoops.

00:30:46 Let's see what happens now.

00:30:51 And we'll just let them sit, see what happens to them a little later.

00:31:00 Okay, well, let's see how we're doing with these,

00:31:04 with the alcohol. I knew we had a little bit too much here, but let's add some more to it.

00:31:10 Now, let's see what's happening to this over here. Well, you can see that the kerosene is freezing here, and it's

00:31:23 almost frozen. What I'm going to try to do is to get this out.

00:31:29 There it is. And what I have here is no ice cracks now. Where are we?

00:31:44 What I have here is a kerosene candle. Let's see how that's going to work. Stand by.

00:32:14 So

00:32:29 I have a pretty long wick on it. That was a mistake, I guess.

00:32:32 But this lecture is full of mistakes anyway. Come on.

00:32:36 What's that? It was planned. No, no. It's a result of not planning.

00:32:49 Okay, well, we'll just let the kerosene candle go for a while and see what's...

00:33:02 Well, still going.

00:33:05 Okay, we'll just let it go and get back over here and see what's happening to our

00:33:14 ethyl alcohol. You see that what's happened to it, it has become frozen. What we really

00:33:21 have is a situation where we have some hard liquor now.

00:33:29 Okay, well, what I'd like to do now is... Actually, it's getting a little too hot here.

00:33:50 It's a little too warm, so I'm going to take this off.

00:33:59 And I think that's...

00:34:07 Well, I'm glad you agree. Okay, let's see what happens to this

00:34:11 balloon here when we add some liquid nitrogen to it.

00:34:20 A little more. I can't find any more. There's more.

00:34:29 Who wants it? Let's just leave it. Let's let it sit there.

00:34:36 Okay, and you see the...

00:34:49 Now, now I...

00:34:58 That's a $25 balloon. Mr. Hirsch would like to get it back.

00:35:06 Now, as some of you know, in fact, at least one person in this course knows

00:35:11 that I taught at the University of Illinois because his brother took my course there,

00:35:15 and he tells me that the lectures are a little bit better, but the jokes get worse every year.

00:35:20 And so, in order to salute Illinois, I'd like to ask Vincent Talley to come out

00:35:24 and do a little rendition for us here.

00:35:54 Thank you.

00:36:19 Bucky, I really appreciate you coming out here with that...

00:36:22 What's that thing that you're holding? Can I handle it? What do you do with it?

00:36:31 Play lacrosse with it? Bucky, what I'd like to do to make up for singing Hail to the Orange,

00:36:38 Hail to the Blue is have a few demonstrations just to try to make you happy and to prove

00:36:43 to you that my allegiance now is to Wisconsin, okay? You'll let me do that?

00:36:48 That's a dumb animal.

00:36:55 Okay, what we're going to do now is have a salute to Wisconsin,

00:36:59 so Vincent Talley will also come out and try to redeem themselves.

00:37:09 Since you guys did the singing...

00:37:18 You watch carefully, Bucky, now. Bucky?

00:37:26 No, it'll go. Okay.

00:37:33 No singing this time?

00:37:48 You! What is happening here? Is anything supposed to happen? There you go, Bucky, how about that?

00:38:05 Well, Bucky, I'm gonna do something that you're used to using a gas that is

00:38:12 very rare in the atmosphere. That's helium, and you just watch this, Bucky, see if you like it,

00:38:17 okay?

00:38:32 Good evening, hockey fans.

00:38:37 How's that, Bucky? Is that good? Okay, I guess I got a pretty heavy dose of that. Let's see what

00:38:49 we're gonna do next here. Okay, well, what I'd like to do, Bucky, is dedicate this poem that

00:38:59 was written to you and see if it meets with your approval. This poem was written by a variety of

00:39:06 people that contributed significantly to it, and I'd like to share it with you.

00:39:14 It goes something like this. There once was a girl from Nantucket.

00:39:21 No? You don't like that?

00:39:23 Okay, I'll try another one, Bucky, okay? I'll try to keep it decent. It goes something like this.

00:39:30 Once upon a Christmas dreary in the lab of Shakashiri.

00:39:37 Christmas, you say, and in the lab. Oh, it's okay. It's better than driving a cab.

00:39:44 It's better than driving a cab. Ring, do I have to explain that to you? Ring, ring stands stood in

00:39:54 darker gloom, scattered widely around the room, so thin and spare that none could match the cedars

00:40:02 of Lebanon. Do I have to explain that to you? I was born in Lebanon. No mistletoe there was for

00:40:10 kissing. Even you, the stars were missing. I didn't write this. You'll get to the part that

00:40:20 I wrote, so I'll get to it. Once suddenly there was a knock. Shiri stood in a state of shock.

00:40:27 I didn't write this one either. Out from the hood jumped Santa Claus, holding one or three books in

00:40:34 his paws. Your lecturer enjoyed the glow of the complete combustion of Drago.

00:40:46 I wrote that one. Santa started to do some flips when he heard about chem tips.

00:40:54 Then he shrieked, from my helper keep abreast. She's not taking your hourly test.

00:41:00 Keep your hands off my sweet blonde. I know about your covalent bond.

00:41:18 He was being completely unfair. As a Lewis acid, all I wanted was a pair.

00:41:30 Santa, while he could, started leaving through the hood. He disappeared with fan and fair,

00:41:40 and Shaka Shiri standing there, saw an end point in the air. How's that, Bucky?

00:41:46 Well, Bucky, I'd like to do one more thing for you before you leave.

00:42:01 And what I'd like to do is, in front of you, show my appreciation to

00:42:10 the person who really got me some hockey tickets this year. But before we do that,

00:42:19 I want to see the effect of the liquid nitrogen on this rose. And you see, nothing really happens

00:42:27 to it. It just gets colder and rises to the top, and we have this rose here. So I'd like to ask

00:42:36 Chris, if you'd come out here, please. I'd like to present you with this as a token of

00:42:42 appreciation for getting me the hockey tickets. Actually, you've been a good sport.

00:42:57 Here's a nice real one for you.

00:43:06 Is that you I smell, Bucky? Bucky, you've been a good sport also. Here's one for you.

00:43:12 Thank you very much for coming, and Merry Christmas. Thanks, Bucky.

00:43:15 Okay, what I want to do now also is continue with this series of demonstrations and look at

00:43:32 the effect of liquid nitrogen on life. We've seen the effect of liquid nitrogen on a flower,

00:43:38 and what I want to do now is get some more liquid nitrogen. Here we go.

00:43:43 And put some liquid nitrogen in the beaker and try to cook some breakfast. What I'm going to do

00:43:56 is cook a three-minute egg here by cooking it in liquid nitrogen. Let's see what happens

00:44:03 to it as we go through the cooking. I'm also going to take some grapes and cook those.

00:44:12 I'll put them in there and see what happens to the food when we go down to low temperatures.

00:44:28 I keep running out of this stuff. You see the liquid nitrogen is boiling there.

00:44:33 The egg is cooking away, and we'll see what happens to it.

00:44:42 We'll add a little more here, and we're running out of liquid here, so let's add

00:44:54 a little more there and see what's happening. Now, as the egg is boiling away,

00:45:03 let me just put a little more liquid nitrogen here. I keep running out of this stuff.

00:45:13 Watch this.

00:45:19 Now, let's see what happens to our grapes. They're really frozen. What I'm going to do is

00:45:25 throw them out to you and ask you not to eat them. I'll try my left.

00:45:36 There we go. You can pass them around. Don't hold them too long. There we go,

00:45:42 because they do give you a frostbite eventually. Let's see what's happening to our three-minute egg

00:45:49 here. There it is. Now, what we have is a cooked egg. There we go. It's not really well cooked.

00:46:11 In fact, it's probably similar to the eggs you get in the dorm.

00:46:21 You know what? To see the effect of liquid nitrogen on life, I went this morning to

00:46:28 the city pond and picked up a little animal, which I'd like to bring out right now.

00:46:33 Come on, little fellow. Come on. Come on.

00:46:44 Here he is, our little fellow here. We're going to put him in the liquid nitrogen and cook him.

00:46:58 We're going to see what happens to him as we do this cooking.

00:47:09 It's a 19-cent ball. Wow. I think I'll keep it. He's boiling away there.

00:47:16 See what happens. How are you coming along?

00:47:19 He's really coming along nicely. Let's see how he's doing. Doggone.

00:47:32 Really.

00:47:41 Louder, louder.

00:47:45 Okay, now we're really coming to the end here. I would have liked to demonstrate to you the

00:47:50 properties of liquid oxygen, but we see we're running out of time. I do want to acknowledge

00:47:56 the help of all the teaching assistants that helped me this semester and hopefully will help

00:48:01 me next semester. I also want to acknowledge the help of the television people in preparing,

00:48:07 making this possible. I especially want to thank Tally and Vince for the help that they did.

00:48:21 I'd like to get Tally to come out here because this is a special occasion. Before

00:48:25 we go on to Christmas break, I would like to get Tally here to do a little demonstration

00:48:32 completely on his own. If he screws it up, it's his fault. If it turns out fine,

00:48:36 then he should get the credit for it. So, Tally. This one? This one.

00:48:46 You want to tell us what you're doing? Yeah. I just want to demonstrate some

00:48:49 colors in the Christmas spirit. So, I have acid and base in these different

00:48:58 beakers, and I'm going to add some indicators to acid, base. That's methyl orange.

00:49:06 Here's methylene blue. No, this is bromothymol blue. Who cares? Acid and base.

00:49:14 And here's litmus.

00:49:18 Acid and base, I hope. Base and acid. Here's phenolphthalein.

00:49:26 Nothing. Nothing in acid. Beautiful and base. But after you've got it done,

00:49:33 further in the Christmas spirit...

00:50:13 Well, thank you very much for coming. Good luck on your finals, and have nice holidays.

00:50:21 You gotta come to the...