00:00:00 Good evening and welcome to this special lecture. I'm very happy and very pleased that so many

00:00:29 of you are able to join us tonight. We are going to do a whole series of experiments

00:00:33 with the assistance of a number of people. Before we do any experiments, though, we want

00:00:39 to make sure that we obey all the safety regulations. To begin with, I will put my eye protection

00:00:45 on my safety goggles, and I want you all to know that we have available, in case we need

00:00:51 it, a fire extinguisher. This fire extinguisher will be used only if it's needed. We hope

00:00:57 that we don't need it tonight. We are going to have, I hope, a lot of fun, and we are

00:01:02 going to, as I said, be doing a series of experiments. Many people are scheduled to

00:01:08 help me do these experiments in this special lecture. I'm going to begin by asking for

00:01:16 some help and see if I can get some help now. Here's a series of beakers that we need

00:01:25 to use. Here's Bucky. Oh, come on in, Bucky. Come on in, Bucky. Hi, Bucky. We have a lot

00:01:40 of special experiments for you, Bucky. I would like to ask you to help out, but you didn't

00:01:46 bring your safety goggles with you, so we can't ask you to help out. Can you stay and

00:01:51 watch the experiments? Why don't I take you to a seat that I have specially reserved for

00:01:56 you over here? All right, here's a seat. Okay. Now, Bucky, we have a special salute

00:02:17 for you and for all the Wisconsin fans, and I'm going to ask Fred to go through with the

00:02:24 salute for you. So, Fred? This is a better way to use beakers than any way that most of you

00:02:30 know about. Those beakers contain special chemicals that we're going to be using very

00:02:50 shortly, but we'll just set them aside for the moment. To begin with, then, we're going

00:02:55 to talk about household chemicals and show some of the properties of household chemicals.

00:03:00 As you look around the tabletop here, you see that there are many different samples

00:03:05 of household chemicals. Now, you hear me use the word chemicals, and I mean to use that

00:03:10 word chemicals, because everything that's around us is made up of chemicals. I want

00:03:14 each one of you now in the audience to touch a chemical. Touch a chemical. Has anybody

00:03:20 touched their nose or touched their cheek? We're all made up of chemicals, and we need

00:03:27 to learn about the properties of chemicals. What I have here, then, is some household

00:03:32 chemicals. We're going to look at their acid-base properties, specifically their pH properties,

00:03:40 and I'm going to ask for some help in doing this experiment. I have many friends in the

00:03:45 audience, and I want to call on one special friend to begin helping me. That's Alex. Alex,

00:03:51 you want to come out and help? Come on out, Alex. Of course, we have a special set of

00:04:01 goggles for you, so you can wear the goggles. What I'm going to do, Alex, is you step over

00:04:06 there. I'm going to take a few samples of this cabbage. I have some cabbage here. See

00:04:15 that? It's red cabbage, right? We're going to try to make some cabbage juice. We'll cut

00:04:20 this off like that, and we'll chop it off a little bit, like so. Sounds like the stuff

00:04:25 your parents might do at home, right? Try to be careful not to cut our finger. Then,

00:04:33 what we'll do is take this cabbage and put it in this blender. You're watching carefully

00:04:39 what I'm doing, right? Take this out of the way so everybody can see. We'll take the vanish

00:04:44 and the milk and magnesia out of the way. Put this over there, like so. Maybe I put

00:04:53 a little too much there. That's about enough there. What I'll do now is add some water

00:04:57 to the blender. What should we do before we start the blender? Put the top on, because

00:05:03 we don't want anything flying out. Then, we're ready to push the button. Can you push the

00:05:08 button for me? Push. Now, we'll stop it a little bit and mix it up. You've seen your

00:05:16 parents do that, too, right? You always have to do that with the blender turned off, otherwise

00:05:22 it gets hurt. We'll start again. We'll stop this now. What we're going to do in getting

00:05:30 this cabbage juice ready, what we're going to do is filter it. I have a filtering apparatus

00:05:48 over here. We'll pour this out, like so. That's about enough. This is hooked up to a setup

00:05:56 which we call an aspirator. What I'll do is turn the aspirator on. I lost my microphone.

00:06:09 I will take those two out of the way. Turn the aspirator on. You can see that the cabbage

00:06:17 juice is falling through. We will collect that cabbage juice and use it as an indicator.

00:06:28 We use substances that are called indicators to tell us whether a certain household chemical

00:06:33 is acidic or basic. Different indicators have different colors. Remember the beakers that

00:06:39 Fred used when he played on Wisconsin? Those had acid-base indicators in them. We're making

00:06:44 a special indicator right now. We have enough juice that has come through. What we'll do

00:06:50 is stop. That's about enough. We'll take this off and set it down. We have some cabbage

00:07:05 juice here. What we'll do is put a little bit of juice in like so. You see that it's

00:07:15 a big flask with distilled water in it, Alex? Can you reach that? Just open it up a little

00:07:22 bit and fill this beaker with quite a bit of water. That's good. What we'll do now is

00:07:30 try to measure whether a substance is an acid or a base depending on the color this indicator

00:07:49 solution will turn when we add that substance to the solution. You see what I have in front

00:07:55 of us here is a rack, a test tube rack, that has 1, 2, 3, 4, 5, 6, 7, 8 different solutions

00:08:05 in the test tubes. There's a number on the top of each test tube. That is the pH value

00:08:12 that corresponds to this color that we see in the tubes. What we're going to do first

00:08:18 is you grab a test tube like that. What we're going to do is take some baking soda. I want

00:08:28 to take this spatula and put some baking soda in the tube. Can you do that? Put a little

00:08:34 bit of baking soda in there. That's good. Then we'll add a little bit of water. Can

00:08:42 you reach for a glass rod? Dissolve that. Stir it up a little bit. Hold it from up top

00:08:54 like where I'm holding it so everybody can see what you're doing. It's dissolving. Baking

00:08:59 soda is soluble in water. It's going to dissolve some more. Then what we'll do is add a little

00:09:06 bit of indicator to it. You see the indicator has changed color. Mix it up some more with

00:09:11 the rod. The color that we have is going to be close to one of the colors that we have

00:09:20 on the rack. What I want you to do is take this tube and try to compare it to the color

00:09:26 closest to it. Which one is it closest to? Somewhere around there. Then we know that

00:09:32 the pH of baking soda is about 7. Let's try a couple of different other things. You grab

00:09:37 another test tube. We'll take some vinegar. If I put some vinegar in here, what color

00:09:47 do you think it will be? What is it now? It's colorless liquid. When we add the indicator

00:09:55 to it, what do you think will happen? It will be red. That's what you predicted. You tell

00:10:04 me now. Compare it to the other tubes there. The pH is about what? Between 2 and 4, so

00:10:12 it's about 3. That's acetic acid. Let's do one more. Let's try this one. This is household

00:10:20 ammonia. What do you think this is going to be? Do you think it's going to be green? Have

00:10:30 you done experiments before? Yes. Do you like doing experiments? Yes. You weren't too sure

00:10:37 they were for a while. We'll add some indicator. You were right again. It was green. You mix

00:10:45 it up a little bit and compare the color. This is some examples of household chemicals

00:10:54 and how their pH values can be determined using an indicator that we made from cabbage.

00:11:02 Thank you, Alex, for helping out. I appreciate it. All of you give Alex a hand.

00:11:15 Now, what I want to do is carry out another experiment. This experiment is to be done

00:11:23 in this large beaker. It has water in it. In this beaker, I'm going to put in it some

00:11:33 baking soda. We'll add some baking soda. We learned that baking soda dissolves, so we'll

00:11:41 mix it up. Stir it up like so. We'll get this out of the way so we can do more experiments.

00:11:57 I'm going to shift this over like so. It's more fun to do experiments if somebody else

00:12:05 is helping, so I want to try to see if I can get somebody else to help me. How about Laura?

00:12:10 Is Laura here? Laura, do you want to come and help? Are you ready? Come on out. You

00:12:15 come with me, okay? I'm going to stand up up here. I'm going to put your safety goggles

00:12:20 on. Okay. I'm going to stand up here. I'm going to put my safety goggles on. I'm going

00:12:35 to put my safety goggles on. How old are you, Laura? You're five? You like doing experiments?

00:12:45 You want to help me do this experiment? Okay. I'll tell you what we're going to do. We're

00:12:49 going to take some spaghetti. What I want you to do is to take this spaghetti and break

00:12:55 it up into small pieces. Can you do that? All right. Is that too many? All right. Let's

00:13:05 break them up. That a girl. Some more. Okay. Now what I want you to do, Laura, is to put

00:13:19 the spaghetti in this beaker. It has sodium bicarbonate. Just drop them in there. Can

00:13:24 you reach? You see what happens to the spaghetti? It sinks to the bottom of the beaker. Put

00:13:28 some more in there. Okay. Are your goggles falling off? All right. Now what we're going

00:13:36 to do is add some vinegar to this mixture. What do you think will happen when we add

00:13:42 vinegar? You don't know, right? Well, a lot of people don't know. That's why we do experiments,

00:13:47 to find out what happens. So let's do an experiment. We add some vinegar. And what do you see

00:13:55 happening? Is it fizzing? That tells us that something is happening. We'll take this rod

00:14:02 out. This fizzing is carbon dioxide. Carbon dioxide is forming, you see, and it bubbles

00:14:09 out. Bubbles up, actually. Now look what's happening to the spaghetti. What's happening

00:14:15 to it? Can you see what's happening to it? You want to tell me? You don't want to tell

00:14:24 me? Well, can you see that the bubbles are around the spaghetti, and they lift the spaghetti

00:14:29 to the top, and then when the bubbles leave the spaghetti, the piece of spaghetti comes

00:14:33 down? You can see that, right? That's because the acetic acid that's in the vinegar has

00:14:38 reacted with the baking soda and is releasing carbon dioxide. We can... You're a big hit

00:14:46 with the audience tonight. Did you know that? You like it, don't you? Well, we'll watch

00:14:58 this for a while, and now you can go back to your seat and watch from over there. So

00:15:02 thank you very much for helping, Laura. Okay?

00:15:16 Welcome, Santa. Come around, Santa. Come around. Come around.

00:15:36 I have some presents here for you. Did I hear you say that you have presents for me?

00:15:38 Yes, for you in particular.

00:15:41 I made a wish list, and I'm happy to see that you're here, and let's see what you got.

00:15:45 Well, I got some very good ones. I hear you do a lot of experiments with balloons. Am

00:15:52 I right?

00:15:53 I do, yes.

00:15:54 Okay. Well, here are some...

00:15:56 Oh, wow. Look at that.

00:15:57 ...beautiful balloons.

00:15:58 Oh, my goodness. Thank you. Thank you.

00:16:01 Now, you know, I know a lot about you.

00:16:03 You do?

00:16:04 Because I keep tabs on everybody.

00:16:05 Uh-oh.

00:16:07 And I hear you're a very sharp fellow, so I brought you this sharp needle.

00:16:13 Oh, thank you. That was on my wish list, too.

00:16:17 Well, that's very good.

00:16:19 Yeah, yeah.

00:16:20 I also hear you often get very thirsty.

00:16:23 That I do, too.

00:16:24 So I brought you something to drink.

00:16:26 Oh, thank you. Thank you, Bucky. That's very kind of you.

00:16:30 Bucky.

00:16:31 Bucky's over there.

00:16:32 Okay. Now, I hear you're raising a lot of money these days for your Institute for Chemical Education.

00:16:37 Yes, indeed I am.

00:16:38 So I brought you all this money.

00:16:40 Oh, thank you. Thank you. Wow.

00:16:43 Okay, and just in case that's not enough, you can stretch it with this rubber band.

00:16:49 Thank you, Santa. It's very kind of you to stop by. I know you have...

00:16:53 Well, wait. I have one more.

00:16:54 You have more?

00:16:55 Now, this one speaks for itself.

00:16:56 Uh-oh.

00:16:58 I think I might use that, too, Santa.

00:17:01 There you are. Okay.

00:17:02 Thank you very much.

00:17:03 Merry Christmas.

00:17:04 Same to you. And I want to thank you for stopping by. I know you have a busy schedule.

00:17:08 Can you stick around for the rest of the program?

00:17:10 Oh, I think I could. I'm ahead of things this year.

00:17:12 Well, that's good. I know Bucky would like to sit next to you.

00:17:15 Oh, that would be great.

00:17:16 Same to you.

00:17:17 That would be great.

00:17:18 Okay?

00:17:20 Thank you.

00:17:32 Now we've...

00:17:41 They seem to be getting along fairly well.

00:17:44 One of the presents that I got is this can of soda.

00:17:52 And I want to do an experiment with this.

00:17:54 You know, beverages such as this one are carbonated.

00:17:57 They have a lot of carbon dioxide in them.

00:17:59 Just like the carbon dioxide that we have released with Laura's help in this experiment.

00:18:05 So what we're going to do is move over here and...

00:18:09 You forgot something, Santa.

00:18:11 Forgot something.

00:18:14 Let me pass it on to you.

00:18:15 You need that.

00:18:16 Yeah, right.

00:18:22 Okay, let's take this baby bottle and take some of this liquid that's in here.

00:18:32 You heard the can when it opened.

00:18:35 You heard a noise, right?

00:18:37 That told us that something was happening.

00:18:39 Let's stop for this.

00:18:42 And see what happens if...

00:18:46 See, make sure this is sealed right.

00:18:48 Small baby bottle with some carbonated beverage in it.

00:18:53 And look what's happening to the...

00:18:58 Now, it wants to know that this piece of rubber...

00:19:02 I have another piece of rubber over here.

00:19:04 Just exactly the same as that one.

00:19:06 It's very strong.

00:19:08 It cannot be blown if you try to exhale into it.

00:19:10 So I'll try.

00:19:11 And so that tells you something, tells us all something

00:19:17 about the amount of carbon dioxide that's dissolved in this can of soda.

00:19:23 So you see that there is a lot of carbon dioxide that is in carbonated beverages.

00:19:31 And we better release this pressure a little bit before this bursts, right?

00:19:34 Let's see.

00:19:35 You want it to burst?

00:19:37 Okay, well, all right, all right.

00:19:40 Okay.

00:19:46 So we'll let that go for a while now.

00:19:49 And see what happens as we look at other properties of carbon dioxide.

00:19:55 Now, carbon dioxide, we all know is a gas.

00:19:57 It also happens to be a substance that exists in a solid form.

00:20:01 And it exists in the form of dry ice.

00:20:04 And I have some dry ice.

00:20:07 I'll reach over and get some dry ice from over here.

00:20:11 You know what?

00:20:13 I just noticed that we have these beakers sitting around.

00:20:15 We haven't done too much with them.

00:20:17 Maybe Fred, we can call Fred again and Fred can do a salute to Santa Claus.

00:20:23 Fred, can you do that?

00:20:24 Oh, sure.

00:20:25 I'll take it right out in front of Santa Claus so he can hear it real well.

00:20:28 Okay.

00:20:29 What kind of songs would you like to hear, Santa Claus?

00:20:32 Christmas carols.

00:20:33 Christmas carols.

00:20:34 Well, thank you, Fred.

00:20:55 The experiment we want to do deals with solid carbon dioxide.

00:21:00 We call that dry ice.

00:21:03 And dry ice is very, very cold.

00:21:05 Its temperature is minus 78 degrees Celsius.

00:21:08 That's why I'm wearing the gloves to protect my hand from the cold.

00:21:12 Now, dry ice is a substance that sublimes.

00:21:15 It undergoes a process called sublimation.

00:21:17 That means it changes from the solid state to the gaseous phase directly,

00:21:22 to the gaseous state directly without becoming a liquid.

00:21:25 Well, I said it is a carbon dioxide, a solid carbon dioxide.

00:21:30 We want to do a couple of experiments with it

00:21:32 with the acid-base indicators that Fred has brought out here.

00:21:35 So I'll try to drop some chunks of dry ice into these different beakers.

00:21:40 You see that the carbon dioxide bubbles off.

00:21:45 And we see some moisture condensing near the top.

00:21:51 And as we add some more,

00:21:56 we might see if there are some chemical changes that are taking place.

00:22:00 You see that some of the colors are changing already,

00:22:03 telling us that a chemical reaction has taken place.

00:22:07 And this is a mixture of different mixtures of acid-base indicators.

00:22:11 And we now have evidence that carbon dioxide itself

00:22:15 is a substance that behaves as an acid in water

00:22:19 because it causes different changes in these different indicators

00:22:24 that we have placed in those beakers.

00:22:26 So let's let that bubble for a while,

00:22:29 and move on and do a couple of other experiments with the dry ice.

00:22:33 Let's take a look at this piece of rubber here.

00:22:37 Boy, that's really very, very tight.

00:22:39 It's about to explode. We don't want that to happen.

00:22:41 So I'll just release it.

00:22:44 I'll try to release it.

00:22:48 Okay, so that's...

00:22:53 We're going to have explosions. Just be patient.

00:22:57 We're going to have real explosions, not nothing like that.

00:23:01 Okay? Where was I here?

00:23:03 I was talking about dry ice.

00:23:05 And I want to do an experiment involving dry ice,

00:23:10 and also a different substance, which is limewater.

00:23:14 Now, limewater is a solution of calcium hydroxide.

00:23:18 I'm going to take these three pilsners

00:23:20 and put some calcium hydroxide solution.

00:23:22 That's limewater.

00:23:24 Put that like so.

00:23:26 And what we're going to do is try to see

00:23:31 if I can get some volunteers to help me do this experiment.

00:23:36 We're always trying to do some experiments all together.

00:23:39 And so, you want to come out and help me?

00:23:41 Come on out.

00:23:43 Come on, come on.

00:23:46 How about you? You come out and help me too.

00:23:49 Yeah, you.

00:23:51 Okay?

00:23:53 What I'd like you to do is to hold this pilsner like so.

00:23:58 Stand where I'm standing.

00:24:00 Okay? What's your name?

00:24:01 Laurie.

00:24:02 Laurie? Another Laurie, okay.

00:24:03 What's your name?

00:24:04 Kevin.

00:24:05 Kevin, you hold this like so from the bottom.

00:24:07 Just like she's holding it from the bottom.

00:24:09 I'm going to give each one of you a straw.

00:24:12 You can let go of that.

00:24:14 Hold it like that, right?

00:24:15 You come and stand right next to her.

00:24:18 That's good, all right?

00:24:19 So I'm going to give you a straw.

00:24:20 Here's a straw for you.

00:24:22 And here's a straw for you.

00:24:24 And when I count to three, what I'd like you to do is exhale into the liquid.

00:24:30 Don't drink the stuff now, okay?

00:24:32 Don't drink it.

00:24:33 So, you understand what we're going to do?

00:24:35 You blow very gently into it, and we'll watch and see what happens.

00:24:37 Are you ready?

00:24:38 Okay, put the straw in there.

00:24:40 One, two, three.

00:24:42 Very gently.

00:24:44 Now, I don't want you to hyperventilate, then you'll pass out.

00:24:47 Yeah, that's good.

00:24:49 The rest of us are trying to watch and see if anything is happening.

00:24:53 We look for different changes that may take place.

00:24:57 Do you see any changes?

00:24:59 Yeah, what kind of changes do you see?

00:25:01 It's turning cloudy.

00:25:03 You're right.

00:25:04 That's what's happening.

00:25:05 Okay, let's stop now.

00:25:06 You feel okay, both of you?

00:25:07 All right.

00:25:08 All right.

00:25:09 Thank you very much.

00:25:10 Give them a hand for helping me, please.

00:25:12 Thank you.

00:25:16 Now, what they've done is shown by this experiment that what we exhale,

00:25:23 what they exhale contains carbon dioxide,

00:25:26 because carbon dioxide reacts with lime water to form calcium carbonate,

00:25:31 a substance which does not happen to be soluble in water.

00:25:35 It does not dissolve in water, and that's what this cloudiness is.

00:25:39 Now, we can do the same experiment much faster.

00:25:43 You see I have the third pilsner over there.

00:25:45 Take a chunk of dry ice, and we put the dry ice in,

00:25:50 and you see that the bubbling takes place,

00:25:52 and the cloudiness develops much more rapidly.

00:25:54 That's because there is a higher concentration of carbon dioxide in the dry ice

00:26:00 than there is in our lungs.

00:26:02 The liquid turns very cloudy,

00:26:05 and we'll watch and see what happens if we let the reaction go further.

00:26:09 That's what we look for when we do experiments,

00:26:11 changes to see if we have evidence for a chemical reaction of any type.

00:26:17 Now, this reaction that's taking place,

00:26:19 that has taken place in all of these three pilsners,

00:26:22 is the formation of solid calcium carbonate, which is limestone,

00:26:27 and those of you who have been to Blue Mounds, to the caves,

00:26:30 have seen calcium carbonate form there.

00:26:33 In fact, you've seen another reaction taking place there, too,

00:26:36 that's taking place in this middle pilsner.

00:26:38 What's happening to the liquid in the middle pilsner?

00:26:42 Is it remaining cloudy, or is it changing?

00:26:46 It's getting lighter.

00:26:48 That means that the insoluble material, limestone, is dissolving,

00:26:53 forming another substance we call calcium bicarbonate,

00:26:57 and that happens to be a soluble substance.

00:27:02 You see, it's quite clear right now.

00:27:04 Calcium carbonate is a substance that is formed very readily,

00:27:13 and in areas such as ours, in Madison, for example,

00:27:17 we know that all our houses and all our homes have in them water softeners.

00:27:23 We have water softeners because we want to remove the hard water,

00:27:28 the so-called hard water, which is due to the presence of calcium ions

00:27:33 and magnesium ions.

00:27:35 I have some samples now of what I'm going to show you right here.

00:27:39 This is a flask that contains in it some hard water

00:27:43 that has not been run through the softener.

00:27:45 Now, hard water, as I said, has in it calcium ions and magnesium ions,

00:27:51 and what we want to do when we use a softener

00:27:54 is to remove the calcium ions and the magnesium ions

00:27:57 because they form an insoluble substance with carbonate,

00:28:01 as we've just seen before.

00:28:03 The way we do this is we take the hard water

00:28:06 and we run it through the water softener,

00:28:09 and I have an example of what is inside the water softener.

00:28:14 What we want to do is run it through a substance

00:28:17 which we call an ion exchange column.

00:28:21 We want to exchange the calcium ions and the magnesium ions

00:28:25 for a different set of ions, namely the sodium ions

00:28:28 that happen to be soluble.

00:28:30 Now, why do we want to do this?

00:28:32 We want to do this because the properties of hard water,

00:28:34 I have another sample of hard water here.

00:28:36 If I take some soap, for example, and add it to the hard water,

00:28:44 and try to, see, it doesn't froth very much.

00:28:48 I took some liquid soap, it doesn't froth very much,

00:28:51 but I have some soft water over here

00:28:54 that has been run through the softener.

00:28:56 I take some soap, add it in, and stopper this,

00:29:02 and you see you get a lot of froth,

00:29:05 and that's why we run the hard water through the softener.

00:29:07 So that's what we're going to do now.

00:29:09 Take some hard water, add it, open this,

00:29:17 and what we're collecting down below is soft water,

00:29:23 water that has the calcium ions and the magnesium ions removed.

00:29:27 These are removed because they are exchanged

00:29:30 on this ion exchange material, this resin,

00:29:33 and every now and then, you know, we add sodium chloride,

00:29:36 we add salt to the water softener.

00:29:38 That's when we recharge this column.

00:29:41 After it gets saturated with calcium ions and magnesium ions,

00:29:46 we remove them, and what we remove them by

00:29:48 is flushing the whole column with a solution

00:29:52 that contains sodium chloride.

00:29:54 That's why the salt is used.

00:29:56 So let's stop now and see if this is indeed softened.

00:30:03 Let's see, here's some soap.

00:30:10 And I'll borrow this stop from here,

00:30:12 so I don't splash it all over the place.

00:30:15 And you see the soft water behaves the same way as this sample did.

00:30:19 And that's how the softener in our homes works

00:30:23 in order to remove the hardness of water,

00:30:26 namely the calcium ions and the magnesium ion.

00:30:29 Now we've seen some examples of different behavior of carbon dioxide

00:30:33 and the solution of carbon dioxide.

00:30:36 I want to show you one more property of carbon dioxide.

00:30:41 We all know that carbon dioxide is a substance

00:30:44 that's used in fire extinguishers, right?

00:30:46 It's used to put out fires.

00:30:49 And what we're going to try to do now

00:30:51 is to show that that is indeed its property.

00:30:54 So what we'll start working with is

00:30:58 get a flame going.

00:31:01 And what I'll do is take some...

00:31:04 Oops, this is the wrong hand.

00:31:07 Take this one.

00:31:09 I'm going to take some chunks of dry ice

00:31:12 and put them in the bottom of this beaker.

00:31:15 What happens to dry ice when we let it sit like so?

00:31:18 It sublimes.

00:31:20 It changes directly from dry ice to dry ice.

00:31:23 And what happens to dry ice when we let it sit like so?

00:31:26 It sublimes.

00:31:29 It changes directly to a gas.

00:31:32 And I'm going to take this piece of wood, light it up,

00:31:36 and what do you think will happen to it if I put it down there?

00:31:41 See, it goes out,

00:31:43 telling us that carbon dioxide

00:31:46 does not support the combustion of wood.

00:31:49 Now, you know that carbon dioxide fire extinguishers

00:31:53 are not used for all types of fires,

00:31:56 only for certain types of fires.

00:31:58 If you have a fire in the kitchen,

00:32:00 the kitchen has a lot of metallic items in it.

00:32:03 You don't want to use a fire extinguisher

00:32:06 that has carbon dioxide in it,

00:32:08 because, well, let's see what happens.

00:32:10 If I take a piece of magnesium, which is a metal,

00:32:13 and I'm going to put this in the flame,

00:32:16 and it starts...

00:32:18 You see, it's very bright.

00:32:20 Don't look at it directly, but you can see it's quite bright.

00:32:23 I put it inside here, and let's see what happens.

00:32:27 I have another piece of...

00:32:29 I lost most of it.

00:32:31 Now, carbon dioxide, you see,

00:32:34 supports the combustion of magnesium,

00:32:37 so metals should not be...

00:32:39 If you have a fire with a metal involved,

00:32:42 you should not use a carbon dioxide fire extinguisher

00:32:46 for that purpose.

00:32:48 One more time, see?

00:32:50 And it just burns out completely,

00:32:53 and you should not use, as I said,

00:32:57 a fire extinguisher that has carbon dioxide in it

00:32:59 for putting out fires of that type.

00:33:01 Now, we've seen different examples

00:33:03 of the chemistry of carbon dioxide.

00:33:05 I want to show you one more,

00:33:07 and this has to do with doing an experiment.

00:33:09 This experiment involves, again, an acid-base indicator.

00:33:12 I want to see if I can get somebody

00:33:14 to help me do this experiment.

00:33:16 Gene, are you ready to help me?

00:33:18 Okay, come on out and help.

00:33:20 I have a pair of goggles for you here.

00:33:23 Okay?

00:33:25 What we're going to do

00:33:27 is carry out an experiment over here

00:33:29 in these three flasks,

00:33:31 and we're going to use some seltzer

00:33:34 and some acetic acid

00:33:37 and some indicator.

00:33:40 What I'd like to ask you to do

00:33:43 is to put 50 milliliters of acetic acid

00:33:47 into this flask,

00:33:50 and then 50 milliliters of the carbon dioxide

00:33:54 will be dissolved in this bottle

00:33:56 into each of these other two flasks.

00:33:58 Okay?

00:34:05 That's good.

00:34:16 Okay, so that's the carbonated water.

00:34:24 Another 50 ml into the second one.

00:34:26 That's good.

00:34:28 We'll take this out of the way,

00:34:30 and then we'll take this out of the way, too,

00:34:33 and put the acetic acid

00:34:38 into this one.

00:34:40 So we'll remember that the two flasks on our left

00:34:43 have in them the soda water that's carbonated,

00:34:47 and the flask on our right has in it,

00:34:51 will have in it shortly,

00:34:54 the acetic acid.

00:34:56 So go ahead, Gene, and put that in there.

00:34:58 Now, we've learned tonight

00:35:00 that these substances are all acidic,

00:35:02 so if we put an acid-base indicator in there,

00:35:05 such as we have in this bottle,

00:35:07 which is labeled bromothymol blue,

00:35:09 why don't you put a few drops of indicator,

00:35:11 like about five in each.

00:35:13 Okay?

00:35:19 And then in this one.

00:35:21 Okay, now what I'm going to do is show you how,

00:35:25 whoops, I've got to get the right reagent.

00:35:28 I'm going to take some sodium hydroxide out of this bottle,

00:35:32 take this and shake this up a little bit like so,

00:35:35 so the indicator is dissolved completely.

00:35:38 We're going to take some sodium hydroxide.

00:35:42 We know sodium hydroxide is a strong base.

00:35:44 It will react with the acid.

00:35:46 What we want to see is how fast it will react.

00:35:48 So we look for color changes.

00:35:50 So are you ready?

00:35:52 Okay, we'll do this.

00:35:54 And you see there was a color change that took place.

00:35:57 That's because the base has reacted with the acetic acid.

00:36:01 Now, I'll do the same thing with the second flask.

00:36:07 And you see there's a change there too,

00:36:11 this change has taken place at a certain rate.

00:36:13 Now, carbon dioxide is involved, of course, in our lungs.

00:36:17 As we exhale, the blood loses carbon dioxide.

00:36:20 Clearly, the color change that's taking place in this flask

00:36:23 is not very rapid.

00:36:25 In fact, if we had to wait for this exchange of carbon dioxide

00:36:28 between the blood and what we exhale,

00:36:31 then that would be insufficient time for us to absorb oxygen,

00:36:35 gaseous oxygen.

00:36:37 What is in the blood then that makes the reaction very fast

00:36:40 is a catalyst.

00:36:42 This catalyst is called carbonic anhydrase.

00:36:45 We want to test the effect of this catalyst

00:36:47 by simply drawing some blood.

00:36:49 Are you ready to do that?

00:36:51 No? Not you?

00:36:53 How about if I do it?

00:36:55 That'll be fine with you?

00:36:57 I've arranged for somebody who's had a lot of experience

00:37:00 in drawing blood,

00:37:02 and that's somebody with training in medical technology.

00:37:06 I want to ask him to come out and do it right now.

00:37:08 So come on out.

00:37:10 Jean, you just watch and see what happens now to this reaction.

00:37:14 It would be okay with you if we drew my blood, wouldn't it?

00:37:18 Fine.

00:37:20 So what we have is now,

00:37:23 we're going to try to get some of the catalyst,

00:37:27 carbonic anhydrase, into this sample

00:37:30 to see if the rate of the reaction is different

00:37:34 than it was without the catalyst.

00:37:36 Remember, these two flasks had the dissolved carbon dioxide

00:37:40 in them from the soda water.

00:37:42 You're sure you've had enough training doing this?

00:37:45 Sure.

00:37:47 Boy, that feels cold. What are you rubbing on there?

00:37:49 That's 70% alcohol.

00:37:51 Alcohol. So then alcohol is evaporating,

00:37:53 and evaporation is a cooling process,

00:37:55 so that's why it feels cold, right?

00:37:57 Bucky, you knew that all along, didn't you?

00:38:00 Okay, I'm ready.

00:38:02 And here we have blood.

00:38:06 Okay.

00:38:14 What is this now?

00:38:16 Capillary?

00:38:18 Okay.

00:38:20 Keep squeezing my finger.

00:38:22 Did I give you a good grade, or what?

00:38:24 Okay.

00:38:27 Did I give you a good grade, or what?

00:38:42 Okay.

00:38:44 Up to the mark. That's enough.

00:38:46 You want to give me something to put on?

00:38:48 Thank you.

00:38:50 A band-aid, too. All right, great.

00:38:52 I'll use that.

00:38:54 Now what I'd like you to do

00:38:57 is put a blood sample into this.

00:38:59 Want to use this to blow it?

00:39:01 Sure.

00:39:03 Will that work?

00:39:05 Yeah, that should work.

00:39:07 Not big enough?

00:39:09 I'm not sure.

00:39:11 How about the syringe?

00:39:13 Will the syringe work?

00:39:15 Might not be big enough.

00:39:17 Let's try.

00:39:19 Okay, so we have some blood,

00:39:21 and that has the catalyst,

00:39:23 carbonic anhydrase, in it.

00:39:26 That's what happens when we add the sodium hydroxide

00:39:28 to see if the reaction takes place

00:39:30 at a different rate than it did in this flask.

00:39:32 So here we go.

00:39:34 See what happens.

00:39:36 You see it was quite fast

00:39:38 compared to the way it was before,

00:39:40 showing the presence of this

00:39:42 carbonic anhydrase catalyst.

00:39:44 So thank you very much for coming to help me,

00:39:46 and Gene, thank you for helping me.

00:39:48 Okay.

00:39:50 Now we're going to do one more

00:39:52 experiment with

00:39:54 carbon dioxide.

00:39:56 Then we're going to move to a different chemical

00:39:58 that's related to carbon dioxide.

00:40:00 What I have here is just an empty trough.

00:40:02 I've got some water that's been boiling.

00:40:04 I'm going to add the water

00:40:06 in here,

00:40:08 and the experiment we're going to do

00:40:10 is a very simple one.

00:40:12 I'm going to find the glove,

00:40:14 and we're going to add some carbon dioxide,

00:40:16 solid carbon dioxide.

00:40:18 And you see what happens

00:40:20 when you add carbon dioxide

00:40:23 like so.

00:40:25 It looks as if we have smoke,

00:40:27 and that's how they make smoke in the movies.

00:40:29 It's one way of making smoke in the movies.

00:40:31 That's because the moisture is condensing.

00:40:33 The moisture in the air

00:40:35 and the moisture from the hot water

00:40:37 is condensing around the carbon dioxide

00:40:39 that's escaping,

00:40:41 and we have this very special effect,

00:40:43 which is due, again,

00:40:45 as I said, to the reaction

00:40:47 between the carbon dioxide that's escaping

00:40:49 and the moisture that's in the vicinity.

00:40:52 Let's move on

00:40:54 to a different kind of chemical.

00:40:56 We've talked about

00:40:58 the oxide of carbon,

00:41:00 namely carbon dioxide.

00:41:02 Now we want to show you

00:41:04 some fancy experiments

00:41:06 with a related oxide,

00:41:08 that of silicon dioxide.

00:41:10 We're going to move over here,

00:41:12 and you've all seen silicon dioxide.

00:41:14 It's no big deal.

00:41:16 Silicon dioxide is nothing but sand.

00:41:18 Sand is silicon dioxide.

00:41:20 This is a sample of sand over here.

00:41:22 You've all played with it one time or another

00:41:24 in a sandbox or what have you.

00:41:26 This is silicon dioxide.

00:41:28 The formula for it is SiO2,

00:41:30 silicon dioxide,

00:41:32 but it occurs in nature

00:41:34 in a variety of forms,

00:41:36 and through the cooperation

00:41:38 of the UW Museum of Geology,

00:41:40 I've been able to obtain

00:41:42 some samples of different minerals

00:41:44 that have in them silicon dioxide.

00:41:46 Here, for example,

00:41:49 is black mica.

00:41:51 You can see the very nice pattern

00:41:53 that it has in it.

00:41:55 Here's another sample

00:41:57 of a mineral

00:41:59 with a very colorful composition.

00:42:01 All of these different samples

00:42:03 contain silicon

00:42:05 in the form of silicon dioxide.

00:42:07 This big chunk that you see over here

00:42:09 is quartz.

00:42:11 Quartz is a special form of glass,

00:42:13 and we want to show you now

00:42:15 some experiments with glass.

00:42:18 We're calling on

00:42:20 the departmental glass blower,

00:42:22 Charlie Amling.

00:42:24 Charlie, come on out here

00:42:26 and let's have some experiments.

00:42:34 Charlie, what do you have here?

00:42:36 You have a tank that has in it

00:42:38 oxygen.

00:42:40 I'll come around and do that.

00:42:44 You need a source of gas.

00:42:48 Got it?

00:42:54 Now what are you going to do?

00:42:56 Are you going to light up the burner?

00:42:58 I'm going to light up the gas.

00:43:02 This is the same kind of torch

00:43:04 that you might see in a welding shop,

00:43:06 but I use it for glass blowing.

00:43:10 What you have is oxygen.

00:43:12 Oh, is it pinched someplace?

00:43:14 Maybe I didn't open it up far enough.

00:43:16 Let's do it again.

00:43:20 Is that better?

00:43:22 Yeah, there you go.

00:43:24 Thank you.

00:43:26 What do you have to do now?

00:43:28 These glasses that I wear are tinted.

00:43:30 They're called titanium glasses,

00:43:32 and they'll filter out part of the glare

00:43:34 from the glass I heat.

00:43:36 I'm going to show you three different types of glasses.

00:43:38 What's the first type?

00:43:40 Soft glass, second type will be quartz,

00:43:42 third type will be pyrite.

00:43:45 They all look the same

00:43:47 when they're not heated.

00:43:49 First I'm going to go with the soft glass.

00:43:51 Soft glass is the same glass

00:43:53 that's used in your windows.

00:43:55 When I'm heating this,

00:43:57 I'm going to warm it up kind of slow

00:43:59 because it'll shatter if I heat it up really fast.

00:44:01 It has a very high thermal expansion.

00:44:07 You should be seeing the glare now.

00:44:09 With these glasses on,

00:44:11 it filters out about 90% of the glare.

00:44:15 What I'm going to do

00:44:17 is just heat it up enough

00:44:19 to make a round bottom.

00:44:23 Take it out of the flame.

00:44:27 Just make a little round bottom.

00:44:29 I'm going to stick it in the glass.

00:44:31 You can see it just shattered

00:44:33 just from the thermal expansion.

00:44:35 Now I'm going to take a piece of quartz,

00:44:37 which is about 99% silicon.

00:44:41 The soft glass was about 72% silicon.

00:44:45 You can see this takes

00:44:47 a lot hotter flame to melt it.

00:44:51 The glare will be a white type glare.

00:45:01 This is actually white hot,

00:45:03 which is about

00:45:05 1700 degrees centigrade.

00:45:07 I'm going to make a round bottom again

00:45:09 with the quartz glass.

00:45:15 Boy, that's very bright.

00:45:17 I'm going to quench it in the water.

00:45:21 You can see nothing happened to the glass.

00:45:23 It didn't break.

00:45:27 This has a different thermal expansion

00:45:29 property than the other glass.

00:45:31 Comparing the two, this has a thermal expansion of 1,

00:45:33 this is 16.

00:45:35 The glass that I use mostly

00:45:37 in glassblowing here in the chemistry department

00:45:39 is Pyrex.

00:45:41 This would be right in between the two

00:45:44 as a thermal expansion of maybe

00:45:46 if one was 16

00:45:48 and the soft glass was 16

00:45:50 and the quartz was 1,

00:45:52 this would be about 6.

00:45:54 So it has both properties.

00:45:56 It's just in between.

00:45:58 I'm just going to heat up the end of this here

00:46:00 like I did the soft glass

00:46:02 and make a big round bottom this time.

00:46:04 I'm actually gathering the glass

00:46:06 up on the end here.

00:46:08 I might just give it a little blowhard here.

00:46:18 Oh wow!

00:46:20 There we go.

00:46:22 Okay, that's the Pyrex.

00:46:24 This is Pyrex 2.

00:46:26 I started a little earlier here.

00:46:28 I want to show you a little bit more

00:46:30 of what I do at work here.

00:46:32 Again, I'm heating up

00:46:34 the glass

00:46:37 and you can see a point out on the one end

00:46:39 of the glass here. I'm going to pull another point here

00:46:41 on the other end.

00:46:43 You can see you have to

00:46:45 rotate the glass continually

00:46:47 because it is a

00:46:49 poor conductor of heat. If you heat one side

00:46:51 only one side will get hot.

00:46:57 As long as you have control of the glass

00:46:59 you can do anything you want to.

00:47:02 There's

00:47:04 one bad thing

00:47:06 about glass.

00:47:08 It looks cool when it's still hot.

00:47:10 I'm just going to cool this off a little bit here.

00:47:18 What I'm going to do

00:47:20 is just try to gather the glass up here

00:47:22 and form a little ball.

00:47:24 Again, I'm

00:47:26 rotating the glass the whole time I'm heating it.

00:47:32 Glass is actually

00:47:34 a liquid

00:47:36 that's an amorphous substance.

00:47:38 That's why it flows like that.

00:47:40 It flows very slowly.

00:47:42 When you heat it, it becomes soft

00:47:44 rather than it melts.

00:47:46 There's no

00:47:48 melting point for glass.

00:47:50 It's just a softening point.

00:47:52 In the hot

00:47:54 glass,

00:47:56 there's no melting point.

00:47:58 It's just a softening point.

00:48:00 The hotter you get it,

00:48:02 the less viscous it gets.

00:48:06 If I just held it in a flame, it would actually

00:48:08 heat up enough that it would drop off.

00:48:10 I continually rotate it

00:48:12 to heat it evenly

00:48:14 and try to get it to the right temperature.

00:48:17 You can see

00:48:19 the Pyrex

00:48:21 has really lent itself

00:48:23 to glassblowing,

00:48:25 especially in laboratory glassblowing.

00:48:39 I just made

00:48:41 a round ball this time.

00:48:43 I didn't get too excited.

00:48:46 I'm taking a piece

00:48:48 of blue glass here.

00:48:50 This is Pyrex glass

00:48:52 that I put some

00:48:54 cobalt oxide in.

00:48:56 It actually turned it blue.

00:48:58 Different oxides make different colors.

00:49:00 I'm just going to add

00:49:02 some color to this.

00:49:16 I'm just going to open

00:49:18 the bowl here.

00:49:28 I'm just going to heat up

00:49:30 the little blue chip

00:49:32 on the end here.

00:49:34 You can do anything you want

00:49:36 with glass.

00:49:38 If you blow on it, it comes out.

00:49:40 If you push on it,

00:49:42 it pushes in.

00:49:44 Once you have control of the glass,

00:49:46 you can make any shape you want.

00:49:54 I just put a little color on there

00:49:56 so you can see the pieces going in.

00:50:06 You're beginning to see what you're making here.

00:50:09 Just a little

00:50:11 Christmas ball.

00:50:13 It looks very nice.

00:50:15 Santa Claus would appreciate

00:50:17 teaching this.

00:50:19 Would you mind giving it to Santa

00:50:21 when you get done?

00:50:23 We have to wait for it to cool off.

00:50:25 That's a very

00:50:27 interesting demonstration, Charlie.

00:50:29 Thank you very much

00:50:31 for coming out to help out.

00:50:33 Thank you.

00:50:39 Thank you.

00:50:45 I'll get the gas

00:50:47 out of the way here now.

00:50:49 Let's move on

00:50:51 to do some other experiments

00:50:53 with a different set of chemicals.

00:50:55 These chemicals are

00:50:59 ones that we're going to make right here.

00:51:01 In making these chemicals,

00:51:03 of course, making any chemicals,

00:51:05 you've got to mix

00:51:08 the reagents together

00:51:10 for a reaction to take place.

00:51:12 I'm going to use these rubber gloves

00:51:14 to protect my hand

00:51:16 from possible spillage

00:51:18 because some chemicals

00:51:20 are not very friendly to the skin.

00:51:22 We always have to be obeying

00:51:24 safety regulations in doing experiments.

00:51:26 You notice that Charlie was

00:51:28 very careful in handling the glass

00:51:30 and you notice, of course,

00:51:32 he was wearing eye protection

00:51:34 so was everyone else

00:51:36 and we'll mix them together

00:51:38 into this beaker

00:51:40 and we'll see if anything happens.

00:51:42 Here we go.

00:51:44 We mix those two together.

00:51:46 We have two viscous liquids

00:51:48 and the next thing we do

00:51:50 is take this glass rod

00:51:52 and mix them up together.

00:51:54 We mixed approximately

00:51:56 about 40 milliliters

00:51:58 of each viscous liquid.

00:52:00 We know that chemicals

00:52:02 don't react with each other

00:52:05 and some reactions are slow.

00:52:07 What we do in science

00:52:09 is try to understand

00:52:11 why some reactions are fast

00:52:13 and why some reactions are slow

00:52:15 and try to get some insight

00:52:17 into the different forces

00:52:19 that hold chemicals together

00:52:21 and the different energy

00:52:23 that's released when chemicals

00:52:25 are mixed together.

00:52:27 We'll mix those two some more

00:52:29 and we'll see what happens

00:52:31 if I stop mixing anything.

00:52:34 We'll wait and see

00:52:36 if anything develops

00:52:38 as we move on

00:52:40 to do a different experiment.

00:52:42 This experiment

00:52:44 I'll do in this beaker

00:52:46 right next to this one

00:52:48 and I will take some liquid

00:52:50 and add this liquid in there

00:52:52 and then try to

00:52:54 take some water.

00:52:56 I had some water around here

00:52:58 someplace.

00:53:00 I'll just use what was

00:53:02 in this

00:53:04 which was soda

00:53:06 and then I'm going to

00:53:08 add some acetic acid.

00:53:10 Add some acetic acid

00:53:12 and we see

00:53:14 that this

00:53:16 liquid that I've added before

00:53:18 has coagulated.

00:53:20 It has formed

00:53:22 a rubbery material.

00:53:24 This is latex rubber

00:53:26 and what we'll do is try to

00:53:28 fish this out

00:53:31 Try to fish it out like so

00:53:33 and

00:53:35 dry it out.

00:53:37 Looks kind of messy.

00:53:39 Get all the water out.

00:53:41 Meanwhile, you're watching

00:53:43 what's happening in the beaker

00:53:45 that I put the reagents in a while ago.

00:53:47 What is happening?

00:53:49 Can you see what's happening?

00:53:55 What's happening

00:53:57 is that we're forming

00:54:00 polyurethane foam

00:54:02 in that beaker

00:54:04 which is a form of a polymer

00:54:06 as is this one.

00:54:08 What I have in my hand right now

00:54:10 is latex rubber.

00:54:12 You've all had many experiences

00:54:14 with using rubber bands

00:54:16 and using different kinds of

00:54:18 properties of material

00:54:20 that involve rubber gloves for example.

00:54:22 What I want to show you

00:54:24 is one property right now

00:54:26 which involves using

00:54:29 Before we do that, let's take a look

00:54:31 at the polyurethane foam.

00:54:33 You see it's rising very

00:54:35 rapidly.

00:54:37 This bicycle wheel, we've had

00:54:39 all the spokes removed from it

00:54:41 and we've replaced them

00:54:43 with pieces of rubber

00:54:45 that have been stretched.

00:54:47 One of the properties of rubber

00:54:49 here's a piece of rubber

00:54:51 is that we can stretch it.

00:54:53 One thing that happens when we stretch rubber

00:54:55 we can do a lot of experiments

00:54:57 with rubber when we stretch it.

00:54:59 I want to ask somebody to come

00:55:01 and help me with this.

00:55:11 What year of school are you in?

00:55:13 I'm a senior in high school.

00:55:15 I'll give you this rubber band

00:55:17 and what I'd like you to do

00:55:19 is to stretch it.

00:55:21 Play around with it like so

00:55:23 and I'd like you to bring it

00:55:26 to your forehead and then stretch it

00:55:28 and put it quickly on your forehead

00:55:30 and tell me what you feel.

00:55:32 What do you feel?

00:55:34 It's warm.

00:55:36 Let's do it again.

00:55:38 Stretch it, put it on your forehead

00:55:40 and put it up front.

00:55:42 Cool it quickly and put it on your forehead.

00:55:44 What does it feel?

00:55:46 It feels cool.

00:55:48 When we stretch the rubber

00:55:50 it gets hot.

00:55:52 What we're going to do now

00:55:55 is take this balloon

00:55:57 that has the rubber spokes in it

00:55:59 with this infrared lamp

00:56:01 and see what happens.

00:56:03 Rubber is contracting

00:56:05 and because of the contraction

00:56:07 the wheel, which is very well balanced

00:56:09 begins to move.

00:56:11 This is one important property of rubber

00:56:13 that we need to know about

00:56:15 and we need to be aware of.

00:56:17 I'm going to do one more experiment

00:56:19 for you with this balloon.

00:56:21 I'm going to take this balloon

00:56:23 that Santa Claus gave me.

00:56:25 Why don't you put your safety goggles on, Tricia?

00:56:27 That would be everybody.

00:56:29 Thank you.

00:56:31 I'm going to take this balloon

00:56:33 and blow it up.

00:56:35 No big deal, right?

00:56:39 Just an ordinary balloon.

00:56:41 You see that small vial

00:56:43 at the end of the lecture table?

00:56:45 Can you bring that over here?

00:56:47 That yellow one.

00:56:49 No, this one over here.

00:56:52 What I'd like you to do

00:56:54 is to hold this balloon for me like so.

00:56:56 Both hands.

00:56:58 Give me this.

00:57:00 This is just a little bit of oil

00:57:02 that I'm going to put

00:57:04 on this very sharp needle

00:57:06 that Santa Claus brought.

00:57:08 What I'm going to try to do

00:57:10 is put this needle through the balloon

00:57:12 without having it pop.

00:57:14 Do you think I can do that?

00:57:16 Probably, but you're not sure, right?

00:57:18 Let's find out.

00:57:21 Ah!

00:57:28 There's the needle.

00:57:30 There goes the needle.

00:57:34 Have you ever seen

00:57:36 a knitting needle like this

00:57:38 thrown through this before?

00:57:40 We pull the needle out,

00:57:42 we get the balloon, and it pops.

00:57:44 Tricia, thank you very much

00:57:46 for helping out with this.

00:57:48 Thank you.

00:57:50 I want to thank you all

00:57:52 for coming tonight.

00:57:54 I want to thank all my special guests

00:57:56 for being here tonight.

00:57:58 I hope that you have gotten a flavor

00:58:00 of how fun chemistry can be.

00:58:02 Thank you very much,

00:58:04 and Merry Christmas to everyone.

00:58:20 Fixer, fixer, fixer

00:58:23 Fixer, fixer, fixer

00:58:26 Fixer

00:58:29 Fixer, fixer, fixer

00:58:32 Fixer, fixer, fixer

00:58:35 Fixer