Oxygen - Periodic Table of Videos

00:06:17
https://www.youtube.com/watch?v=WuG5WTId-IY

Zusammenfassung

TLDRIn hierdie video word die eienskappe en reaktiwiteit van suurstof, vloeibare suurstof, en osoon deur middel van verskeie eksperimente bespreek. Dit demonstreer hoe suurstof se ongepaarde elektrone aanleiding gee tot die blou kleur van vloeibare suurstof en hoe die hoë reaktiwiteit daarvan gevaarlik kan wees wanneer dit verkeerd hanteer word. Die video sluit ook 'n eksperiment in waar die heraansteek van 'n gloeiende splinter die teenwoordigheid van 'n suurstofryke atmosfeer bewys.

Mitbringsel

  • 💡 Suurstofmolekules het ongepaarde elektrone wat 'n blou kleur veroorsaak in sy vloeibare vorm.
  • 🚀 Vloeibare suurstof is baie reaktief en gevaarlik in die teenwoordigheid van organiese materiale.
  • 🔬 Osoon is 'n vorm van suurstof wat drie suurstofatome bevat en is meer reaktief as O2.
  • ☀️ In die boonste atmosfeer beskerm osoon ons deur ultraviolet lig van die son te absorbeer.
  • 👨‍🔬 'n Gloeiende splinter kan weer aangesteek word in 'n suurstofryke omgewing – 'n klassieke skoolervaring.
  • 🧪 Chemici is dikwels skrikkerig vir die blou kleur van vloeibare suurstof as gevolg van sy reaktiwiteit.
  • 🔥 'n Demonstrasie wys hoe vloeibare suurstof 'n brandende vuur makliker laat floreer.
  • ⬆️ Neil demonstreer die gebruik van suurstof om 'n hout splinter weer aan die brand te laat raak.
  • 🧲 Vloeibare suurstof toon magnetiese eienskappe in 'n eksperiment.
  • ❗ Ongelukke met vloeibare suurstof kan lei tot ontploffings indien verkeerd hanteer.

Zeitleiste

  • 00:00:00 - 00:06:17

    Die lektor verwelkom die gehoor en kondig 'n eksperiment aan om aan te toon dat die suurstofmolekule, O2, ongepaarde elektrone het. Die reaktiwiteit van vloeibare suurstof word buite gedemonstreer waar sy blou kleur op die tafel gesien kan word. Vloeibare suurstof is sterk oksiderend en baie reaktief. Daar is twee vorme van suurstof: O2, wat ons inasem, en osoon (O3), wat drie atome bevat en 'n V-vorm het. Osoon is reaktiewer as suurstof en help om ultravioletstrale te absorbeer. Die eksperiment maak gebruik van 'n toetsbuis gevul met vloeibare suurstof om sy blou kleur en magnetiese eienskappe te toon. 'n Tradisionele toets vir suurstof word uitgevoer deur 'n gloeiende splint in 'n suurstofryke omgewing te herverlig.

Mind Map

Mind Map

Häufig gestellte Fragen

  • Waarom is vloeibare suurstof blou?

    Vloeibare suurstof is blou weens die teenwoordigheid van ongepaarde elektrone in die suurstofmolekule se atoomorbitale.

  • Watter gevaar hou vloeibare suurstof in?

    Vloeibare suurstof is baie reaktief en kan ontploffings veroorsaak, veral in die teenwoordigheid van organiese molekules.

  • Hoe kan die teenwoordigheid van suurstof getoets word?

    Die teenwoordigheid van suurstof kan getoets word deur 'n gloeiende splinter in 'n suurstofryke atmosfeer te plaas, wat dit sal laat heraangaan.

  • Wat is die rol van osoon in die boonste atmosfeer?

    Osoon in die boonste atmosfeer absorbeer ultraviolet lig van die son en beskerm lewende organismes teen skadelike straling.

  • Hoe verskil osoon van suurstof?

    Osoon (O3) bevat drie suurstofatome gerangskik in 'n V-vorm en is meer reaktief as suurstof (O2), wat twee suurstofatome bevat.

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Untertitel
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Automatisches Blättern:
  • 00:00:00
    So comrades, welcome to the lecture. What I am going to do
  • 00:00:06
    now, we’re going to begin with an experiment to illustrate
  • 00:00:12
    this point that the oxygen molecule, O2, has unpaired
  • 00:00:20
    electrons.
  • 00:00:21
    Now we’re outside just to show you the reactivity of this
  • 00:00:23
    lovely stuff here, liquid oxygen. So you can see wonderful
  • 00:00:26
    liquid oxygen is a nice blue colour. So over here on the table
  • 00:00:31
    we’ve got a tin tray which we’re going to use to contain the
  • 00:00:36
    experiment that I’m going to show you next. So we’ve got
  • 00:00:38
    our favourite liquid oxygen. Strongly oxidising; very, very
  • 00:00:44
    reactive, and here I’ve got some cotton wool. So this is the
  • 00:00:46
    same stuff we use to take make-up off, perhaps our partners
  • 00:00:51
    or our girlfriends or our wives, and this is the same stuff we
  • 00:00:53
    use to wipe our babies’ bums.
  • 00:00:55
    Oxygen is an interesting element because it exists in two
  • 00:00:58
    forms: the taught form which we breathe all the time is O2,
  • 00:01:03
    two oxygen atoms joined together; and there’s another form
  • 00:01:07
    called ozone, and which has three atoms arranged like the
  • 00:01:12
    letter V, or letter V this way up.
  • 00:01:16
    Oxygen has unpaired electrons within the molecular orbitals,
  • 00:01:19
    in the atomic orbitals around the structure, and these
  • 00:01:22
    unpaired electrons give rise to colour and that colour is blue.
  • 00:01:26
    So blue is often perceived to be the colour of solvated or
  • 00:01:29
    unpaired electrons, and you can see here the lovely blue
  • 00:01:32
    colour. Now lots of chemists are really scared when they see
  • 00:01:35
    the blue of liquid oxygen, because liquid oxygen is very, very
  • 00:01:39
    reactive. Generally you only make liquid oxygen by mistake.
  • 00:01:42
    Not like today when we’re making some on purpose. And if
  • 00:01:45
    you’ve made it by mistake in an uncontrolled way, where
  • 00:01:48
    there might be organic molecules perhaps simple organic
  • 00:01:50
    chemicals like hydrocarbons, grease or perhaps a highly
  • 00:01:54
    elaborate compound then, they tend to detonate and they
  • 00:01:57
    tend to cause very energetic experiments.
  • 00:01:59
    Yeah it’s very fluffy it’s not very reactive. It doesn’t really
  • 00:02:03
    burn, it cinders, might smoulder. But here we go, we’re going
  • 00:02:06
    to pop it in the tray.
  • 00:02:08
    So we begin with Neil’s very high-tech piece of equipment,
  • 00:02:13
    which is a test-tube on a piece of string. What we’re going to
  • 00:02:16
    do is to put some liquid nitrogen in here. You can see liquid
  • 00:02:24
    nitrogen – well you may not see – is colourless. Ok? So this is
  • 00:02:30
    liquid nitrogen, and what I hope you can see is that this
  • 00:02:35
    magnet, which is a pretty good magnet. Let me just show
  • 00:02:40
    you here with my keys, that they stick pretty strongly to the
  • 00:02:46
    magnet. The magnet has absolutely no affect at all on the
  • 00:02:52
    liquid nitrogen. I can pull the magnet and nothing happens.
  • 00:02:55
    And then we’re going to fill up all of the void space, so all of
  • 00:02:58
    the space in the cotton particles with oxygen. So you might
  • 00:03:03
    want to stand back after this bit Brady. So here we go, here’s
  • 00:03:05
    our liquid oxygen. Do you want to come in and zoom in on
  • 00:03:09
    me?
  • 00:03:10
    It’s ok, I’ve got it zoomed nicely.
  • 00:03:12
    Ok, so here you can see the lovely blue liquid oxygen colour,
  • 00:03:15
    going into the cotton wool particles.
  • 00:03:17
    Let’s try the same thing with liquid oxygen. Careful of my
  • 00:03:27
    shoes…
  • 00:03:28
    So here we have a match on a stick, and I think you can see
  • 00:03:30
    its probably alight, so we have our fire, we have our oxygen,
  • 00:03:34
    and we have our fuel. Now let’s see what happens when we
  • 00:03:35
    put them all together.
  • 00:03:37
    The liquid oxygen is a very nice blue colour today. So now
  • 00:03:43
    let’s try, here’s the magnet again, and if I take the liquid
  • 00:03:48
    oxygen you can see I can pull it right up here. It’s not as
  • 00:03:55
    magnetic as my keys, but you can see there’s a really big
  • 00:03:58
    difference. It sticks to the magnet. So you can see it really is
  • 00:04:03
    magnetic.
  • 00:04:05
    You ready? Ok. Woohoo and there she blows!
  • 00:04:15
    And ozone is much more reactive than oxygen. So near the
  • 00:04:21
    earth’s surface, where you and I are at the moment, ozone is
  • 00:04:25
    really quite dangerous because if you breathe it in it can start
  • 00:04:28
    reacting with any sort of molecule that has bonds between
  • 00:04:34
    carbon. But in the upper atmosphere, ozone is extremely
  • 00:04:39
    important because it absorbs ultra-violet light that comes
  • 00:04:42
    from the sun and stops this ultra-violet light attacking the
  • 00:04:47
    molecules in biological species on the surface. If it wasn’t for
  • 00:04:51
    the ozone in the upper atmosphere all of us would be, if not
  • 00:04:57
    dead, certainly very much less comfortable than we are at the
  • 00:05:01
    moment.
  • 00:05:02
    So Neil’s now connecting up a piece of tube to oxygen
  • 00:05:05
    cylinder and he is going to fill up this gas jar with oxygen and
  • 00:05:08
    we are going to do a really classic experiment: the one that
  • 00:05:10
    everyone learns at school and tests for oxygen, which is to
  • 00:05:13
    relight a glowing splint. So we have a traditional gas jar full of
  • 00:05:19
    oxygen. So here you can see we are burning a splint. Ok, so
  • 00:05:24
    this is the wood burning in excess oxygen around us, ok. So
  • 00:05:29
    what we are going to do is we are going to take the splint out
  • 00:05:32
    so it is just glowing. And if I blow on this splint you can see it
  • 00:05:35
    gets brighter. Now we are going to try and relight that splint
  • 00:05:40
    by putting it into a very oxygen-rich atmosphere. So we’ll
  • 00:05:43
    move over to the jar and we’ll put in our glowing splint and
  • 00:05:47
    you can see the flame comes back to life. So that’s a test that
  • 00:05:50
    everyone learns for an oxygen-rich environment.
  • 00:05:53
    What happened? What made that happen?
  • 00:05:54
    Well the increased oxygen content/concentration reignites and
  • 00:05:58
    reinitiates that oxidation of the wood or the burning of the
  • 00:06:02
    wood. So we’ll do that again. So there we go: flame again.
Tags
  • suurstof
  • vloeibare suurstof
  • osoongas
  • reaktiwiteit
  • chemiese eksperimente
  • ongepaarde elektrone
  • ultraviolet lig
  • suurstofryke atmosfeer
  • gloeiende splinter