[speaker001:] Right now listen folks. sh sh sh sh sh. Can I remind you please if you're answering a question can you please put your hand up so I can select. Some of you know Now way back a couple of weeks ago when we were doing the group seven the one that's spelt F C L B R I A T. Hands up who can remember what any of those stand for without looking on er
[John:] You forgot the first rule put your hand up. Right fluorine is the actual element fluoride is the stuff that's in?
[speaker001:] Toothpaste.
[John:] Toothpaste very good. You never put your hand up. Right C L
[speaker001:] Please sir is chloride
[John:] Chloride is the is when it's joined up with something chlorine is the element. And what do we get chlorine in?
[speaker001:] Swimming baths.
[John:] Swimming baths to?
[speaker001:] To take away all the nasty To kill the germs.
[John:] Well it doesn't exactly kill them kill the it's got it's own smell which sort of tends to mask the smell but it's also basically to kill the germs. B R?
[speaker001:] Bromine.
[John:] Bromine very good. And I?
[speaker001:] Iodine.
[John:] Very good excellent. S so what I want you to show you this morning is how we can actually make the chlorine. So the people at the front yeah if if you come up a little bit closer....... Now sh sh sh sh.... Please... Now... I've got erm a bottle which is actually contains some chlorine here but it's not called chlorine liquid. I'll scratch this. Hydro
[speaker001:] Chloric. Chloric.
[John:] chloric acid and it also says... C O N C. Conc what is conc short for? It's short for a word yes. It starts with C O N C. Anybody? Conc is short for?
[speaker001:] Nose [LAUGHTER]
[John:] No conc er... it's the beginning part of a word. If you use the word conc you're just meaning your nose.
[speaker001:] Conical.
[John:] Ah now we're getting a bit more scientific. Conical if it was conical it would be C O N I conical. But it's conc. Now can you think of a wo c think of a word that describes the state of this liquid. And I'm going to hold the top while I show you. It's rather oily and it's quite a a dense liquid.
[speaker001:] Is it dangerous?
[John:] It is dangerous yes. I'm gonna get some goggles on in a minute.... What do you call liquid ah I'll give you a clue. What do you call a liquid that's very very strong?
[speaker001:] Concentrated liquid.
[John:] Thank you concentrated. Now I... Goggles on time folks. Now in this particular case I'm using a tap funnel... Tap funnel... just as it's... it's... Erm the concentrated acid you don't just sort of pour it in and run away and leave it to it. Let it in a little bit at a time.... Just slow... Slowly let the acid in. Then turn it off. Right now so the tap is to control the speed at which the acid goes in and if there is any gas that's in there it can't escape out of that pipe again it's got to go down the other pipe. So it's a safe it's a safety feature and it helps control the experiment. So we control the speed at which the acid goes in. And once it's in there it prevents the gas from escaping. Now at the moment the black chemical that's in there is not doing a great deal. The black powder's just sort of gone to a a sludgy paste. The powder's just gone it's dissolved a little bit but it's not really doing much on its own. So in order to speed it up a little bit we might need need to heat it up. Who said that?
[speaker001:] Me.
[John:] Well done. Now who's going to go next door to get the gas switched on?
[speaker001:] What?
[John:] Right... Listen again sh sh sh sh sh.
[speaker001:] Done it.
[John:] Sh Now... in order to help this black powder to split up the acid. We're going to have to heat it up a little bit. Now again I'm treating it carefully I'm not just sticking the bunsen underneath and blasting away at it. I've got the... Graham wanted to well unfortunately Graham this one's a bit dangerous so I'm having to do it so if anything goes wrong it's me that gets it and not you.... Well because I've got all the dirty chemicals... Sh.... Please.... Erm... How will we know... how will we know if there's any gas escaping? What. What's this paper?
[speaker001:] P H paper.
[John:] P H paper. So I'm going to moisten it.... Because of the gas that's drifting around in here... What?
[speaker001:] The gas can you can you set fire to it?
[John:] No it's not a flammable gas. But it is poisonous so if I start smelling it I'm going have to switch the cupboard on to suck the fumes away. Lorraine. Now this P H test I've only had it a few seconds and already look what it's done to the paper.... Where I've wet it what's it done to it?
[speaker001:] Turned it yellow.
[John:] It's turned it yellow and where it was dry it's now going what colour?
[speaker001:] Red.
[John:] Red. Red means it's
[speaker001:] An acid.
[John:] an acid. And because this takes what do you call something what do you call something that takes the colour away?
[speaker001:] Bleach.
[John:] those are old pieces of paper. Come on somebody what do you call a chemical... A what? Not a neutralizer.... Andrew? We call a chemical that takes that takes Now you'll see it. What colour's the gas?
[speaker001:] Green.
[John:] Right it's a green gas... and it's also what it does it to this paper turns it acid to start with and then takes the colour away it is a bleach. Bleach gas.... Now because it was frothing up I've turned the bunsen off... to control the reaction it's slowing down again now. And you can see the colour. What colour's bromine on that list?
[speaker001:] Black.
[John:] Black. What colour's iodine on that list?
[speaker001:] Black. Blue.
[John:] Not it's not blue. Purple And they're all poisonous... and they will bleach this the be this is probably the best bleacher. This is highest the highest up up the list that we can do. We can do reactions from F too dangerous.... Now sh sh sh sh sh... sh. Now this one I'm going to show you this one this time. Karina?
[speaker001:] Mm?
[John:] Why do we use the tap funnel again? Cos we've got a tap funnel.
[speaker001:] so if there's any gas
[John:] Yeah right it can't get out it has to go down the pipe.
[speaker001:] Sir?
[John:] Stop shuffling. Sh. Can anybody oh I bet you'll never guess this one. Why have I got a conical flask instead of a round flask? Here's the answer. The round flask is broken. Erm I've go some purple crystals believe it or not.... now this one's a bit more powerful this purple chemical.... Shouldn't need heating up. If I put this white... if I put the white paper behind the flask, can you see the gas that's in there?
[speaker001:] Yes a yellowy gas.
[John:] Yellowy gas right and
[speaker001:] Sir?
[John:] Yes?
[speaker001:] Is that flammable?
[John:] It's not flammable it's poisonous it's acid and it bleaches. It could yes in the in the First World War er they used... It would
[speaker001:] But how long would it take?
[John:] It depends how much you got into whether you had asthma or not. You might you might have after you've s had some of this. Now can I explain this part over here look at this. Sh sh. Er right I've got this contraption upside down leading into a a trough of water. Can anybody guess why? There's something else that this gas does in water. If you'd got enough gas it would make bubbles. But we've only got a small supply remember. It may do. What do what do things normally do in water. Sometimes they move yeah. Anything else if you just put some Right they sink or float. What else do they do after they've either sunk or floated?
[speaker001:] Rust.
[John:] They might rust yeah. Or... turn to a well what do you call it when they turn to a liquid. What's the word? They what?
[speaker001:] They liquidize. Liquidize.
[John:] They liquidize but you can liquidize things by heating them up that would liquidize them but in this particular case you just mix them with some water what's the process called? To turn it into It's called what? If you stir some sugar into water.
[speaker001:] Dissolves.
[John:] It dissolves okay. If this gas... if this gas dissolves too quickly it'll suck the water back up the tube and into this flask. It could be dangerous because if you're sucking water into acid you could have problems. So Lorraine I've got this upside down funnel and that prevents the water from being sucked up. How do I know I've got some chlorine in the water. Well look what's happening to these test papers.... They're not acid any longer what's happened to them? Mark what's happened to that that test the P H paper there?
[speaker001:] It's all gone white.
[John:] It's gone white what's the pr what's the pr what do we call it it's been?
[speaker001:] Bleached.
[John:] Bleached. So I've got some bleaching yeah smell you can smell that bleach. I've got some bleaching chemical. Wave it past your nose you don't sn Don't don't just I'll just wave it past your nose. You don't want to much cos remember it is er poisonous.... Anybody else want... no? You want a smell?... Right.... So... sh sh sh sh sh let's just sum up.... What was the liquid we started with?... What was the liquid we started with?
[speaker001:] Erm oh that conc
[John:] Concentrated hydrochloric acid. It's got chlorine in it. We used a black chemical to start with but in order to that to help that we needed some heat. And this one works on its own this purple chemical is more powerful and works on its own. Adam can you go and turn the gas off? Right now... I don't know Mr. 's trying to book some.
[speaker001:] What?
[John:] Erm science trips.
[speaker001:] Where to?
[John:] Somewhere in
[speaker001:] The Science Museum in London?
[John:] No no no erm somewhere in Yorkshire.
[speaker001:] Somewhere where?
[John:] Somewhere in Yorkshire. Er yes a gas gas gas fired power station. Right can you go back to your places. Right now
[speaker001:] Sir have s have you seen Pride and Prejudice and the telly?
[John:] Can you look after those folks. Well well did anything happen when I put the acid in? Did any any of you three see what anything that happened in the first one. so we had to put some a bit of heat in. Nothing happened acid on its own. Now we got. Let's... Right excuse me. too small. Erm... does anybody know what this M N O two business is? Have a look on your your periodic table and see if you can work out what M N O two. You should know what O O stands for. M N O two anybody?
[speaker001:] Nitric oxide.
[John:] Something oxide yeah. Part way there come on M N have a look on your page one of this module. Work look up what M N stands for.... Anybody worked it out come on M N O two.
[speaker001:] Magnesium.
[John:] Very close but not quite right. Not magnesium.... Have a look look very close it's not mag it's... No oh that's capital N this is a little N M N.... That's it right. M N
[speaker001:] Oxidizes
[John:] Go on read it what is it?
[speaker001:] Magnesium.
[John:] No have you looked closer.
[speaker001:] Manganese.
[John:] Manganese manganese oxide.... Please. There you go.
[speaker001:] ...
[John:] Manganese oxide erm the back row decided. Manganese oxide. Erm
[speaker001:] Excuse me sir thanks sir.
[John:] universal liquid. Or a piece of universal paper or. What does K M N O four stand for? What does K stand for anybody work that one out on your periodic table. K for anybody remember cos we've done this group.... What's this paper paper called?
[speaker001:] P H.
[John:] Yeah that's P H.... Yes it is. No not chrome.... Anybody... what's K?
[speaker001:] Potassium.
[John:] Well done. Yes I know because it's come from an old an old word an old.... Er K potassium yes. Erm then we've got a manganese K M N O four. It's got two metals. How which one's got most which one's got most oxygen in it the K M N O four or the or the M N O two?
[speaker001:] M N O two.
[John:] Why?
[speaker001:] That's a guess.
[John:] Well look at the numbers. M N O two K M N O four.
[speaker001:] Oh I thought K M N O four.
[John:] Yeah why?
[speaker001:] Cos it's got number four.
[John:] It's got four oxygen atoms and that's only got two oxygen atoms. Well done Michael. So K M N O four's got more oxygen.... Erm... what does this word property mean in number four? Property. Now you're gonna tell me a property is something that you can Yes something that's good about it very good. So what's what what are what's chlorine got that say no other gas has? It's a germ killer yeah anything else?
[speaker001:] Er.
[John:] How would know it if I brought a jar full into the room?
[speaker001:] Smell it.
[John:] Smell it. Right erm what else. How would we know a jar was full compared with an empty jar. Just to look at if the lid was on.
[speaker001:] You can see it.
[John:] Why?
[speaker001:] You can smell it.
[John:] No we've the lids on this time.
[speaker001:] Sir it was oily and you can see it.
[John:] No... that was some drops of acid that you could see We're trying to work out what the properties of this gas if you're not listening you won't be able to do number four. It's smelly it's yes it's poisonous yes that's a property good. Another one? Mm that's a use not a property.... What colour It's yellowy green yes How we doing folks?... Good.
[speaker001:] Sir I've finished.
[John:] Right goo you know that erm acid thing you were doing this one... be finishing that off. I dunno I can't remember.
[speaker001:] You marked it.
[John:] and have you done a key
[speaker001:] Yes.
[John:] Well a key should have a little bit at the bottom to say what what's it stands for. Oh you've done that red ones, yellow ones, where's your yellow ones Your key doesn't match your chart. You've put green ones and they're the metals. Your green ones are the alkali earth metals. You've got this all all wrong. Tell you what I'll get you another one.... How are we doing ladies okay? Number five oh Can anybody tell... er on number five why we got the upside down funnel. No. Now come on this is a check of who was listening Why have I why have we got that upside down funnel? Sh sh sh sh. Sh sh er no. What does the gas do to the water? Mark Mark Mark. It does... but it might also do the gas might do something else as well.
[speaker001:] Turn the water green.
[John:] How could it turn the water green what would it have to do in the water?
[speaker001:] Bubble.
[John:] Come on we're going back to this shove it in water business again.
[speaker001:] Oh it dissolves.
[John:] Dissolves stop it from sucking the liquid back again. dissolves to the stop the liquid from being sucked back into. The gas dissolves. the gas starts to come off when I just put the acid in. Yeah so you've got to heat it up. paper some P H erm Darren Darren sit down please. that funnel right now how did we control the speed at which the acid went in. With a tap. And then once all the acid was in if you left the tape open what would happen to the gas? It would just escape so we sh close the top and the gas has got to.
[speaker001:] Down the tube and into
[John:] Yeah down the other tube and into the what's the thingumajiggy?... What do you call it that tall cylinder thing? Thingumajiggy? You'll never guess it's for collecting gases so we call it a
[speaker001:] Gas.
[John:] Gas jar.
[speaker001:] Not far off.
[John:] Oh. Now come on. Speed it u yeah cos the black powder wasn't powerful enough. Can anybody tell me why the black powder's not powerful enough. Look at the shorthand for it M N O two it's not got so much?
[speaker001:] Oxygen.
[John:] Very good it's not got so much oxygen. So you've got to give it some heat to help the oxygen to work.... Now if anybody's finished and is wondering what to do check through and make sure everything is up to date. And then I've got some work here for those who thing everything's up to date.... So don't start this work until everything else is up to date. It's on the end of this. And if anybody's been away and has got or has got missing sheets I've got spare sheets down here. Question sheets... Don't forget your acid posters by the way.... Or you getting another one.... It's Right I would.... The only problem is I haven't got many colours. You'd you'd do better to use your own colours if you've got.... How are you doing okay Dean? Oh right well you need Oh not again. Right who can tell yes go on Michael.
[speaker001:] To let the acid in.
[John:] To let not out to let what in slowly. The acid in slowly right. It lets the acid in slowly and once the acids in what does it stop next?
[speaker001:] Carbon dioxide
[John:] So whatever's in there can't get out up there it's got to go through another pipe it's got to go through the other pipe. Two two reasons. To stop the... gas from escaping and to let the acid in bit by bit.
[speaker001:] Sir?
[John:] Yeah. Er you could put P H or universal or any antacid indicator.
[speaker001:] Sir
[John:] Properties... who can tell me a property of this gas. Look at it in through the in the fume cupboard I can see one from here.
[speaker001:] Green.
[John:] It's green right good.... It it's a bit misty alright fair enough that's a property. Anything else? If it can fall down out of that pipe into the jar it must be? Very good be heavy. If it erm sucks the water up if you're not careful it must. How can it suck the water up by? It hasn't actually done cos I put that funnel on the end to stop it from doing it. Yeah it would cause a vacuum as it dissolves. So it dissolves obviously. Have you got the smell one have you put the smell smell one down. Smells of? Swimming baths or bleach or... You can put some universal indicator or erm P H paper or To stop it from sucking because it dissolves too well It's like you in there drinking drinking er coke out of a straw if you you suck enough... It'll all end up in your mouth. If you just put a pipe straight in the end of the liquid it would suck the liquid up. Right Darren if you've finished the qu To s stop from sucking up Now who's finished?... Number three you could on the filter paper I've out some of those P H test papers. You could put universal, P H, litmus anything. Oh yeah probably we don't stop just cos you're not. Are there any I've got the index out here if you want one.
[speaker001:] I'll thank 'em all very much then.
[John:] Oh fine you want to thank them now.
[speaker001:] Can I thank you all very much for being cooperative. [tape ends]