00:00:00 Hello, I am Harry Sello. It is my pleasure to introduce Tempest in a Test Tube, a television show which made its debut August 24th, 1955, on KQED Channel 9, the educational station for the San Francisco Bay Area.

00:00:22 Tempest was a series of 53 half-hour shows pioneering a new approach in which I, as lecture demonstrator, gave live, unrehearsed presentations of a series of chemical experiments.

00:00:37 These were designed to illustrate basic, simple chemical principles. The purpose was to stimulate an interest in chemistry by teenage students and by adults.

00:00:50 The talks and experiments had to be entertaining, educational, and simple. Spontaneity and liveliness were key to the approach.

00:01:00 All the experiments used in the shows were designed and constructed by members of the California section of the American Chemical Society.

00:01:09 The participants were employed by the Shell Development Company, Emeryville, and by Chevron Research, Richmond.

00:01:16 A grant of $52,000 from the Ford Foundation and National Educational Television permitted the filming of the first 24 shows of the series.

00:01:27 The management for the ACS consisted of Alan Nixon, section chair, Fred Strauss, TV committee chair, myself as first emcee, and Aubrey McClellan, second emcee.

00:01:41 We four constitute the core of the present committee. The series was extremely popular then with KQED viewers of all ages.

00:01:54 The senior chemist committee of the California section today is determined to revive Tempest for the benefit of elementary schools, high schools, adult education classes,

00:02:08 ACS local sections, historical archives, TV stations, and similar organizations. We believe in chemistry as a second language.

00:02:20 While basic principles have not changed, practices have.

00:02:25 45 years ago, such simple chemical demonstrations were not treated with the degree of safety considerations that they are today.

00:02:34 Today, even such simple demonstrations would be carried out with the proper regard for safety glasses, shields, protective gloves, laboratory coats, and visible fire extinguishers.

00:02:49 The principle of safety first would be explicitly present as part and parcel of a modern Tempest in a Test Tube.

00:03:04 This is a test tube.

00:03:11 This is a test tube.

00:03:19 This is a test tube.

00:03:29 This is a test tube.

00:03:49 Tempest in a Test Tube, a series of experiments designed to explain the mysteries of chemistry and the laws that govern it.

00:03:59 Produced by KQED San Francisco,

00:04:08 in cooperation with the California section of the American Chemical Society,

00:04:17 for the Educational Television and Radio Center.

00:04:23 And now let's go to our laboratory and meet Dr. Harry Sello.

00:04:30 Hello. In this talk I would like to demonstrate the properties of a material which is vital to the life of all of us, oxygen.

00:04:41 Before describing some of the experiments, I would like to start one which will take a little time to develop.

00:04:48 And we can come back and refer to it at a later period in the talk.

00:04:53 Here is a dish containing colored water on which are placed two test tubes full of the same water.

00:05:02 These test tubes have in them two little electrodes, electrical leads that is, which are connected to four dry cells in series.

00:05:12 This nest of dry cells acts as one big battery.

00:05:17 I'll make the final connection and start the experiment.

00:05:27 There, we've connected on that one.

00:05:31 Immediately, bubbles can be seen rising in both test tubes.

00:05:38 And upon looking closely and knowing what to look for, in this test tube, the bubbles seem to be rising much faster than they are in this one.

00:05:47 That is, there are more of them than there are in this one.

00:05:51 Well, let's go on and come back and look at this later in the talk.

00:05:59 About 180 years ago, the following experiment was performed.

00:06:06 A little bit of an orange powder was placed in a test tube.

00:06:19 Perhaps a little more neatly than this, but in the same way.

00:06:36 Just shake that down a little.

00:06:49 Light the burner.

00:07:01 Now let's get this just to the right level.

00:07:11 This bright orange powder is turning darker around the edges where the burner is hitting directly.

00:07:20 Let's let that heat for a moment and describe the experiment a little bit more.

00:07:26 As I say, 180 years ago, this observation was made.

00:07:30 A gentleman by the name of Joseph Priestley, a chemist then,

00:07:36 well, some people called him an alchemist, one of these old-time chemists,

00:07:41 was observing the effect of heat on this orange powder and he made these same observations.

00:07:46 It turned black while heating.

00:07:49 It seemed to liberate some sort of what he called air.

00:07:54 Those days, most all gases were called air.

00:08:00 While this material turned black where it was being heated,

00:08:04 it also started to deposit a light grayish film on the side of the test tube.

00:08:11 And this grayish film is now beginning to be deposited right here.

00:08:14 There's a sharp line of it.

00:08:17 He then, Mr. Priestley did, took a glowing splint, a piece of wood,

00:08:28 got it to just glowing, and put it down over this material.

00:08:32 And about the same thing happened.

00:08:36 The glowing splint burst into flame.

00:08:50 There, again.

00:08:52 This evidence to Mr. Priestley was the discovery of this vital material, oxygen.

00:08:59 He didn't know it was oxygen, unfortunately.

00:09:01 He knew its properties.

00:09:03 He knew what it could do, that it could support combustion,

00:09:05 that mice could live in it for a certain period of time

00:09:08 and would die after the oxygen disappeared.

00:09:10 But he did not call it oxygen.

00:09:13 He called it one of his peculiar kind of airs or gases that he had been studying at the time.

00:09:20 He even went so far as to breathe it.

00:09:23 Well, I don't think we should repeat that part of the experiment.

00:09:26 In those days, they took a little more chances than we do now, mostly because of ignorance.

00:09:31 It remained for another chemist, about the same period, who was acquainted with Mr. Priestley,

00:09:37 to be impressed by this experiment and to go on and study this air a little further,

00:09:43 and this other chemist gave it the name of oxygen.

00:09:46 Let's write these chemists' name on the board.

00:09:57 Priestley, the gentleman who discovered oxygen.

00:10:06 Lavoisier, the man who studied it and gave it its name.

00:10:10 Lavoisier called it oxygen, meaning acid former,

00:10:14 because he knew that oxygen was present in most acids,

00:10:19 so he felt that this element should be called acid former or oxygen.

00:10:24 The material which both Mr. Priestley and Mr. Lavoisier heated at that time was mercuric oxide,

00:10:31 a material composed of mercury and oxygen,

00:10:35 which, when heated, liberates oxygen,

00:10:38 which gives the test that I showed, causes a glowing splint to burst in the flame.

00:10:43 Now, upon cooling, it is turning back to its former color,

00:10:48 the same as it was in the jar, sort of orange, light colored.

00:10:52 Around the cooler portions of the test tube, the gray film is mercury.

00:10:58 Well, the lives of these gentlemen were very interesting,

00:11:01 and the work that they did was extremely entertaining,

00:11:03 and it's certainly worthwhile the time of anyone who is interested to read about their lives,

00:11:08 and I think one book that I would like to recommend is the following,

00:11:13 a book written by Jaffe,

00:11:18 entitled Crucibles,

00:11:26 Crucibles, the Story of Chemistry.

00:11:40 This is just one of many books of chemical history on that very big topic.

00:11:46 I happen to like this one personally.

00:11:48 It's a very romanticized type of story.

00:11:51 Jaffe writes about this in an exciting way.

00:11:56 Well, as I say, Mr. Lavoisier, the chemist who gave oxygen its name, was a brilliant man indeed.

00:12:02 He unfortunately was living in a time when things were really troublesome,

00:12:07 the French Revolution, and because of some very bad mistakes,

00:12:11 Lavoisier was killed as a traitor to his country, which of course he was not.

00:12:16 A lot of accidents did happen then.

00:12:19 He was an unfortunate accident.

00:12:21 No one knows what he could have done had he remained alive.

00:12:25 We call Lavoisier the father of modern chemistry

00:12:28 because of the studies that he made on oxygen and its properties.

00:12:31 In particular, the use that he made of the analytical balance,

00:12:36 a very essential tool in proving the laws of chemistry.

00:12:41 In this next experiment, which was one of the same type that these gentlemen conducted

00:12:46 because it has to do with the properties of oxygen,

00:12:49 in this next experiment, there is here a candle

00:12:52 which is standing in a little puddle of water in a dish.

00:13:06 We've now seen that we can get oxygen by heating a particular chemical like mercuric oxide,

00:13:13 the chemical that Priestley and Lavoisier studied.

00:13:16 We also know that there is oxygen in the atmosphere around us.

00:13:20 Let's look at its effects upon a candle burning.

00:13:24 This candle will get good and started here.

00:13:30 Now, I'll carefully lower this tube over the candle.

00:13:43 And put the stopper on the top.

00:13:46 The level of the liquid is now at the bottom of the dish at the foot of the candle.

00:13:51 And there the candle just went out and see what happened.

00:13:56 The level jumped up to about here,

00:14:00 to a point where the pressure equalized on both sides.

00:14:04 Then a little air got in around the bottom of the tube

00:14:08 and the level fell back down a little ways.

00:14:11 But there it is still rising, still above the level in the dish.

00:14:14 What has happened here?

00:14:16 The candle made use of the oxygen in the atmosphere around us.

00:14:20 It consumed most of that oxygen in burning.

00:14:23 Because the oxygen was consumed,

00:14:26 the pressure inside the tube became lower than that in the atmosphere around the tube,

00:14:30 so that outside pressure forced the liquid up on the inside to equalize pressures.

00:14:35 At the time it did this,

00:14:37 I just saw a little bubble of air run in around the bottom of the tube

00:14:43 and instead of the liquid level being up here,

00:14:47 as it might have been for a moment,

00:14:49 it's actually down here.

00:14:51 The reason the candle went out was because it consumed this very vital material, oxygen.

00:14:57 This experiment demonstrates that a good portion of the air around us is oxygen.

00:15:01 It does not exactly tell us how much.

00:15:04 That has to be done by means of another more complicated experiment.

00:15:08 But we do know that we have in the air around us about 21% of oxygen

00:15:13 with the remainder nitrogen and small amounts of other gases.

00:15:18 This experiment is a demonstration of the process of oxidation.

00:15:23 That is, the process in which oxygen combines with other materials.

00:15:29 This process takes place in nature around us all the time.

00:15:33 The rusting of metals, the burning processes that we see,

00:15:37 a piece of wood or coal or oil burning,

00:15:41 is a process of oxidation.

00:15:43 Of course, in the case of the fuels like that,

00:15:46 we prefer to call it combustion,

00:15:48 which can be really called a rapid oxidation.

00:15:51 But in all of these, oxidation is the process by which some material combines with oxygen.

00:15:58 In this case, the wax of the candle combined with oxygen.

00:16:03 It's of interest to know that in our own bodies at all times,

00:16:07 this same process is taking place.

00:16:11 However, it is not as simple as it would be in the burning of a candle.

00:16:15 If it were, you'd probably say this is why we burned a candle at both ends.

00:16:19 In our everyday living, we call it respiration.

00:16:23 Respiration means the process by which we take in air,

00:16:27 soak up the oxygen into our bloodstream,

00:16:31 let the oxygen be carried around into the blood cells

00:16:35 where it's combined with the fuel that we take in, the food we eat.

00:16:39 The burning or oxidation process takes place in the cells.

00:16:42 Carbon dioxide and unused oxygen, the products of this oxidation,

00:16:47 are carried back out through the lungs and exhaled.

00:16:51 This process of respiration then is nothing more or less

00:16:55 than a sort of a complicated type of oxidation.

00:16:59 In the course of this process then, we use oxygen to combine it

00:17:03 with our fuels, the food we eat.

00:17:06 Let's look further at the properties of oxygen.

00:17:10 To do this, I should take my burning burner over with me

00:17:17 and examine some of these properties of oxygen.

00:17:23 The burner wasn't burning. I'm at the burning issue.

00:17:27 We've shown that oxygen can be obtained from a chemical

00:17:31 by heating that chemical.

00:17:34 Oxygen then can also be obtained from the air around us.

00:17:38 The process in which liquid air is made, for example, is a source of oxygen.

00:17:42 When oxygen is obtained by this kind of a process,

00:17:44 that is by liquefying air and getting the oxygen from it,

00:17:48 we get oxygen in the form of cylinders.

00:17:51 It is contained in cylinders.

00:17:53 Here is a cylinder of oxygen.

00:17:55 The cylinder comes filled with something like 2,000 pounds per square inch

00:18:00 of oxygen and is about as pure as it can be obtained.

00:18:06 The cylinder is now open. This has been used.

00:18:08 It registers something over 1,100 pounds per square inch.

00:18:14 By cranking this, you can hear the oxygen rushing down through the tube.

00:18:19 I will just fill up this little jar full of oxygen.

00:18:26 While the jar is being filled, let me light my burner.

00:18:41 I think the jar is now about filled.

00:18:45 Just adjust the flame of the burner so it can be barely seen.

00:18:48 A slight yellow flame.

00:18:50 It's not the most efficient kind of a way to use the burner,

00:18:53 but at least under these bright lights, the yellow flickering can be seen.

00:18:59 Light the splint.

00:19:03 And let's see if we can find our oxygen.

00:19:13 There it goes, bursting in the flame.

00:19:18 A glowing splint test for the presence of oxygen.

00:19:21 By doing it in this way, I've also shown one of the other properties of oxygen,

00:19:25 not immediately obvious, and that is that oxygen by itself is heavier than air.

00:19:32 Air is a mixture of nitrogen and oxygen, mostly nitrogen.

00:19:36 Pure oxygen is heavier than air, so it would tend to run out of the jar.

00:19:42 Now since I've used it up, I better fill this thing up again.

00:19:52 I can feel the oxygen running around the hand here as I wait.

00:19:59 There, I think that's full.

00:20:04 Let's take this little bit of steel wool.

00:20:09 Fine wires of iron.

00:20:12 And to do this, I really should put on my safety glasses.

00:20:16 Just in case glass wants to fly around.

00:20:20 I'll heat the steel wool. You see it gets slightly or reddish in the flame.

00:20:30 A little bit redder and hotter in the oxygen.

00:20:33 While steel wool glowed in the flame, barely glowed,

00:20:38 it burst into white hot heat and a visible flame in the oxygen.

00:20:42 Not only that, but this must be a very strong piece of glass indeed

00:20:47 because the molten piece of steel wool,

00:20:50 that is the steel wool melted in the form of a red hot bead,

00:20:53 white hot bead, and fell to the bottom of the tube

00:20:56 and as a matter of fact burned a hole right through the tube

00:20:59 because there's a scorch mark left here on the table.

00:21:04 So this process of oxidation is indeed a very striking one

00:21:08 when pure oxygen is used.

00:21:13 This glass, by the way, is made of heat-resistant glass.

00:21:16 This jar is of heat-resistant glass so that it didn't crack,

00:21:19 but a hole did burn through the bottom

00:21:22 due to the heat of the iron being oxidized to iron oxide.

00:21:27 Let's fill this up again.

00:21:30 That should be about full.

00:21:35 This time, we'll take a little bit of charcoal

00:21:39 and examine the effect of charcoal in oxygen.

00:21:46 There are some flakes of charcoal already flying off the tube.

00:21:50 Beginning to get a little red hot in spots.

00:21:55 Oxidation is now taking place in the atmosphere.

00:21:58 The carbon is being oxidized to carbon dioxide,

00:22:01 but it's a very low rate because it uses only the oxygen in the atmosphere,

00:22:05 which is dilute.

00:22:07 The carbon is being oxidized to carbon dioxide,

00:22:10 but it's a very low rate because it uses only the oxygen in the atmosphere,

00:22:14 which is dilute.

00:22:16 Let's see. Let's see what happens if we shake this into the oxygen here.

00:22:20 Bursts into more glowing sparks than it was here.

00:22:27 The illustration here, then, is that the process of oxidation

00:22:30 in the presence of almost pure oxygen, 100% oxygen,

00:22:33 is much more rapid than it is in the case of just atmospheric oxygen.

00:22:37 Let's go on to the next experiment to see a further demonstration

00:22:41 of the process of oxidation in the presence of almost pure oxygen,

00:22:45 and to see a further indication of oxidation.

00:22:48 Here is a glass tube, a burette,

00:22:52 a stopcock at the top to shut it off.

00:22:55 The bottom part of it is sealed off by being immersed in a dish of water.

00:22:59 So there's a burette full of air now open at this end

00:23:05 and sealed off by being immersed in the water at this end.

00:23:09 I have placed inside of this burette a bit of the same steel wool

00:23:14 of the type that I used here to...

00:23:16 in fact, of this same pad that I used to burn in the jar.

00:23:20 I'll just run some oxygen over this steel wool.

00:23:29 You see, oxygen is not a poisonous gas,

00:23:31 so it can be allowed to escape out into the air.

00:23:33 It just enriches the air around us a little bit.

00:23:36 It might give the speaker a little kick.

00:23:40 I'll run some of this over the...

00:23:43 There it is bubbling through the burette.

00:23:45 I'm running it over the iron, the steel wool that's in the tube.

00:23:49 It's escaping out the bottom, the excess.

00:23:52 Make sure we wash out all the air.

00:23:54 Just replace it with nothing but oxygen.

00:23:57 There, I think that's about ready now.

00:24:00 And I'll shut this off.

00:24:02 At the start, the level of the liquid is the same in the dish

00:24:08 as it is in the tube.

00:24:13 And already, the level on the inside of the tube has begun to rise,

00:24:19 and it's up about a half an inch from the surface of the liquid

00:24:23 on the outside of the tube.

00:24:25 There is an indication that the pressure on the inside of the tube

00:24:28 is being decreased.

00:24:30 Oxygen is being consumed.

00:24:33 And it is continuing to rise even as I watch it here.

00:24:38 What is this process?

00:24:39 Well, this again is oxidation, a very familiar kind of oxidation.

00:24:44 Since this is iron reacting with oxygen,

00:24:48 then this is what we normally call rusting.

00:24:52 By making this take place in an atmosphere of pure oxygen,

00:24:57 why, the rusting process goes on much faster than it would

00:25:00 if the iron were just left lying around out into the air,

00:25:03 out in the air, so that the rusting process is so fast

00:25:08 that the oxygen is being used up and water is rising to replace it.

00:25:15 In fact, some of the iron particles, I can see by looking extremely close,

00:25:21 are getting colored with a brownish covering of iron oxide or rust.

00:25:27 Again, a demonstration, a visible demonstration of the process

00:25:30 of oxidation in action.

00:25:34 Well, let's go on.

00:25:35 Let this sit here.

00:25:37 Perhaps it will rise even further.

00:25:41 Let's take a look at the experiment that we started

00:25:43 at the beginning of the talk.

00:25:46 For this, I will need my glasses and burner.

00:26:03 The action of the battery has now stopped

00:26:07 because this tube is empty.

00:26:11 This tube is about half full.

00:26:15 I'll just disconnect this to make sure that we don't run into any trouble here.

00:26:22 This first test tube now is completely full of gas.

00:26:32 Let's see if we can identify the gas that's in it.

00:26:46 I very carefully hold the test tube in the upside-down position.

00:26:57 Light the splint, and...

00:27:07 That pop you heard was the pop due to the hydrogen

00:27:11 which had filled the test tube, burning as it escaped.

00:27:14 It combined very quickly with the oxygen of the atmosphere,

00:27:18 and the presence of the burning splint exploded, actually.

00:27:22 I had to tip the test tube up to do this,

00:27:24 which proves that hydrogen, then, is lighter than air.

00:27:27 It can escape when the test tube is held upwards.

00:27:31 Let's look at the next one.

00:27:36 This time, I'll let the remaining liquid pour out.

00:27:41 Here's a glowing splint.

00:27:44 Very carefully turn this over, and there, the glowing splint

00:27:47 didn't quite burst into flame, but suddenly, certainly, glowed more brightly.

00:27:52 So the half of the test tube here was filled with oxygen.

00:27:56 Again, in this case, the test tube was filled with oxygen.

00:28:01 Again, in this case, I had to quickly turn the test tube right-side up

00:28:05 so that the oxygen would not escape, since it itself is heavier than air.

00:28:11 Let's look at a short diagram of...

00:28:14 a brief diagram of just this setup, and explain what happened.

00:28:24 Here's the jar.

00:28:27 Here's the jar.

00:28:30 In it is a level of liquid about up to here,

00:28:35 and two test tubes, which were sitting about like that,

00:28:42 on a tray.

00:28:44 I'll just sort of sketch in the fact that there was a tray.

00:28:47 Right about at the level of liquid.

00:28:49 In each test tube, there is a little square piece of platinum

00:28:52 called an electrode.

00:28:57 One piece of platinum was connected through a wire

00:29:03 to one side of the battery.

00:29:05 We'll mark that plus.

00:29:07 The other piece of platinum was connected through a wire

00:29:10 to the other side of the battery.

00:29:12 We'll just mark that minus.

00:29:14 I show these going off to different sides.

00:29:17 Actually, they came around and connected to the dry cells.

00:29:22 This side was completely full of gas.

00:29:26 This side was half full of gas.

00:29:28 Here was the hydrogen.

00:29:30 Here was the oxygen.

00:29:32 So, by the passage of an electric current through the water

00:29:37 into the water of the test tubes,

00:29:39 we separated water into its two components, hydrogen and oxygen.

00:29:44 This is called electrolysis.

00:29:48 Electrolysis.

00:29:53 Two volumes of hydrogen were obtained for one volume of oxygen.

00:29:56 This is where water gets its formula named H2O.

00:30:01 Now let's summarize.

00:30:04 Oxygen was discovered by Priestley,

00:30:07 really identified and named by Lavoisier about 180 years ago.

00:30:14 It is indeed a vital element.

00:30:16 It's important to us in our everyday life.

00:30:19 We breathe it through a process we call respiration.

00:30:23 Pure oxygen is capable of supporting combustion.

00:30:28 Things glow very brightly and even catch fire

00:30:31 when they're immersed in pure oxygen,

00:30:33 such as glowing steel wool,

00:30:35 will oxidize or undergo a process called oxidation

00:30:39 and burn very violently.

00:30:41 In our case, we saw where a piece of molten steel

00:30:44 fell to the bottom of the glass beaker

00:30:47 and burned its way right through the bottom of the beaker.

00:30:51 We then had a further indication of oxidation in the tube.

00:30:56 In fact, I can show you that the water has filled the test tube,

00:31:00 filled this tube rather, by opening it at the top

00:31:03 and dropping the level nearer to where it started.

00:31:06 It actually started at the bottom.

00:31:08 This process also was oxidation,

00:31:11 the iron combined with oxygen to form iron oxide.

00:31:15 This is the process that occurs every day in nature around us,

00:31:19 the rusting of metals, the burning of fuels with oxygen.

00:31:24 Processes which take place slowly in the atmosphere

00:31:28 take place quickly in pure oxygen.

00:31:31 Thank you.

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