[speaker001:] helps me to sort of see how the lesson's going.
[Andrew:] Right.
[John:] So... that's maths is it. [clears throat] How do you feel about last week's?
[Andrew:] Erm it was good, I made a lot of progress in it.
[John:] .
[Andrew:] Compared to usual.
[John:] Yeah.
[Andrew:] Yeah.
[John:] That that's how I felt, that you were getting into it, you were... understanding how the bits tied together
[Andrew:] Yeah.
[John:] and making sense of it. So you're feeling happier with it?
[Andrew:] Yeah a lot better.
[John:] Okay. Erm what you done since last time?
[Andrew:] Erm I did that work you asked me to do.
[John:] Great. Great.... And did it make sense?
[Andrew:] Sort of yeah. I was a bit
[John:] Okay.
[Andrew:] it it got away a bit you know and and
[John:] This this is what I'm saying last time that if you'll work through it, understand it, Oh yeah I can do that,
[Andrew:] Yeah.
[John:] but if you if you if that's all you do then in eve even a week's time but definitely in a few months' time it's just gone. You'll just have this vague memory that, Ooh I could do that once, now where d how do I get started?
[Andrew:] Yeah.
[John:] How do I get into it? So you need the practice. Erm been tending to concentrate on specific things which you know stand a good chance of being on the paper, and even if they're not will help you with others. So how much of it did you understand?
[Andrew:] Erm
[John:] Which bits were you happy with?
[Andrew:] the positive and the negative.
[John:] Okay.
[Andrew:] Erm
[John:] So from your table you could find out
[Andrew:] Yeah.
[John:] there's a good chance that one of the positives will go with one of those negative
[Andrew:] Yeah.
[John:] and you can make something out of it. Right. Now what what were the bits that were a bit tricky then?
[Andrew:] Erm... just remembering say I had to put four O Hs with N H, I was sometimes I was getting it right sometimes I was getting it wrong and stuff like that.
[John:] Right, so for the for the diagram
[Andrew:] It was just where I was putting the four I wasn't sure about.
[John:] Yeah. The diagram was okay. What was physically happening you could relate to that and you got that sorted out. Now how do you put it down on paper? What's the notation? That
[Andrew:] Yeah.
[John:] that's the only problem, okay?
[Andrew:] Yeah.
[John:] So you're understanding it. You could explain that to me.
[Andrew:] Yeah.
[John:] Yeah, you could say what it looked like and what was happening and then say, Well I'm not quite sure what the convention is for writing them
[Andrew:] Right.
[John:] down. Well that's fine. I mean the convention is... each of these ex I mean what you could have, you could put brackets round everything.
[Andrew:] .
[John:] If you think of maths... you can you can put brackets in where you don't need them can't you?
[Andrew:] Yeah.
[John:] So you could put... [whispering] there. [] If I wanted to do something like... three add six I could put brackets round the three and round the six and it wouldn't make any difference. Erm if I put two times... brackets... three add six it does make a difference.
[Andrew:] Mhm.
[John:] Yeah?
[Andrew:] Mm.
[John:] It makes a big difference. Well it's the same with this.... If you put something like... N H... and then O H four... well the convention is that when it's a suffix stuff a subscript... and a suffix below the line there and just after it,... it only applies to the last element.
[Andrew:] Yeah.
[John:] Usually mean the last letter cos most of the elem well a lot of the le the elements have one letter. So that would just be four Hs and one O.
[Andrew:] Right.
[John:] To make it mean that you've got four Os as well you put it in brackets. So with the maths it's like it's the difference between four times O H... or just sort of O plus four H four O plus H. So anything that you've got four of put a bracket round it.
[Andrew:] Right.
[John:] Erm if we had something like erm... N H four... and we had something with a valency of... eight, say, which is impossible
[Andrew:] Yeah.
[John:] but we had one with eight so we'd have we'd have the whole thing there twice.... So how many Hs would you have in that weird thing?
[Andrew:] Er eight.
[John:] Yeah. And how many Ns?
[Andrew:] One. No eight. Two.
[John:] Two. So
[Andrew:] Yeah.
[John:] anything inside your brackets multiplied by what you've got outside just the way you would have two times brackets three add six close brackets. Okay?
[Andrew:] Yeah.
[John:] So it's the same... same with this. It's just a slightly different convention but
[Andrew:] Mm.
[John:] basically it is maths. It's telling us how many sets of different things we've got.
[Andrew:] Right.
[John:] So... let's have a look what we've got here.... So got N A positive O H negative N H four positive and O H negative now what's going on here?... You've got an alkali trying to react with an alkali. Is this... is this what you're supposed to be doing?
[Andrew:] Well that's
[John:] No wonder you had trouble. Is that what I wrote er... right... What that's what I wrote but what I said was, Each of the acids reacting with this starting
[Andrew:] Ah
[John:] with hydrochloric... Okay?
[Andrew:] One.
[John:] These these are two these are two common alkalis.
[Andrew:] Alkalis.
[John:] Okay there's N A O H which is what?
[Andrew:] Er sodium hydroxide.
[John:] Okay. And N H four O H which is?
[Andrew:] Nitrogen hydroxide no no er...
[John:] Have a look in the tables what N H four is.
[Andrew:] N H four ammoni
[John:] Ammonium.
[Andrew:] ammonium.
[John:] Okay. N H three on its own ammonia... when it's combined with something else it's N H four ion and it's ammonium. Like erm chlorine on its own... chlorine combine it with sodium it becomes a chloride.
[Andrew:] Right.
[John:] So let's have a look at that now.... You shouldn't have any problem with... so you've tried there with which acid do you want to use? Hydrochloric's probably the simplest so have a go with that first because then you can see the pattern.
[Andrew:] Er hydrochloric acid is
[John:] erm
[Andrew:] erm... no erm?
[John:] It's got
[Andrew:] Erm
[John:] hydrochloric what does that sound like?
[Andrew:] Hydrogen and chlorine.
[John:] Okay.
[Andrew:] H C L that was it yeah
[John:] Right
[Andrew:] I couldn't remember.
[John:] Okay great. So it's H C L and C L's got a valency of one so that's nicely balanced one C L with one H plus. Erm now you've done that quite a few times before N A O so do the N A O H first and you should be able to whiz through that.
[Andrew:] Yes.... erm...
[John:] So then you can work out which are positive and which are
[Andrew:] Right.
[John:] Hydrogen's the one we tend to treat as a a metal.
[Andrew:] Yeah. Hydrogen is positive.
[John:] Right.
[Andrew:] Chlorine... is a negative. Er... Sodium is a positive. Hydroxide... is...
[John:] You've got one... here there are some on this
[Andrew:] Yeah er negative.
[John:] Right
[Andrew:] Yeah. So
[John:] So most of these are one positive and one negative.
[Andrew:] So the hydrogen with go with hydroxide.
[John:] Okay making?
[Andrew:] Erm... so that's H... two O plus this two H dow there.
[John:] Yeah where does the two go?
[Andrew:] Down there.
[John:] Right. Okay. Two goes down there so it's two what two whatever letter came before it.
[Andrew:] Yeah.
[John:] Two Hs and one O.
[Andrew:] And on the C L we add the... so yeah we get sodium C L is a negative... N A is is a positive how many that's spare one spare
[John:] Okay.
[Andrew:] transfer that's N A C L.
[John:] Yeah that's it. That's
[Andrew:] H two O and
[John:] S O you write the equation out for that now?
[Andrew:] That's... N A... C L
[John:] Erm the sort of
[Andrew:] Erm.
[John:] from what you start with from what it gives. From the hydrochloric acid and the
[Andrew:] Oh right. H... C L plus N A O H is equal to... N A C L
[John:] Right yeah.
[Andrew:] plus H two O.
[John:] Right great.... So what's the sort of general term for this, this is an
[Andrew:] Hydrogen chloride.
[John:] Yeah er what about this then?
[Andrew:] Sodium hydroxide.
[John:] And it's an example of what?
[Andrew:] An alkali.
[John:] Okay this is?
[Andrew:] Er acid.
[John:] So you can just write under it acid plus...
[Andrew:] acid... plus...
[John:] gives
[Andrew:] equals... N A C L is a alkali.
[John:] Erm
[Andrew:] No it's not it's a salt.
[John:] Good it's a salt. And you know what...
[Andrew:] and water.
[John:] Right and that's a general reaction that happens with virtually any acid and any alkali
[Andrew:] acid and any alkali
[John:] salt and water. Er so have another go now at a similar sort of reaction. Same acid this time use a different alkali. Use ammonium hydroxide.
[Andrew:] Which is ammonium N H four
[John:] usually put the acid first
[Andrew:] Right the acid and what acid gonna use?
[John:] So use the same one.
[Andrew:] So H C L plus ammonium hydroxide that's N H... Now it's got four spare ones and the hydroxide has got
[John:] Er whoa whoa whoa now it's N H four right
[Andrew:] Yeah.
[John:] so put the put the four on for N H four. Now if you look it up on the table let's have a look at erm say calcium... double positive. Right zinc double positive this this type of ion
[Andrew:] Triple positive.
[John:] is a triple positive. But N H four so it's a single positive.
[Andrew:] Oh right.
[John:] Okay?
[Andrew:] Yeah.
[John:] So
[Andrew:] It's four hydrogen with the
[John:] Four hydrogen one nitrogen all their bonds got get together and there's one the result is one positive bond left over.
[Andrew:] Right.
[John:] Okay you're not too bothered about what's going on internally
[Andrew:] So it's N H four O H
[John:] So N H four O H because it's it's just one positive on that whole N H four cluster and we we think of that as an entity.
[Andrew:] That's a positive that's a negative er that's a positive that's a... negative.
[John:] Mhm.
[Andrew:] So the positive the negative
[John:] Yeah that's good.
[Andrew:] and the negative the positive.
[John:] That's it tha I like the way you did it because that's a good one to do first the H positive and the O H negative are going to give you the water. Now what are you left over with? it's a nice nice that for working it through.
[Andrew:] So that... put the equals underneath so H... so the chlorine and the N H four... chlorine has got one spare one
[John:] Right.
[Andrew:] and so's N H four so it's N H four C L.
[John:] Right.... Small L's don't forget.
[Andrew:] Oh yeah.... Plus
[John:] Okay so just write the equation out again. No need to write acid plus alkali Okay. Now try do you remember the formula for sulphuric acid?
[Andrew:] Sulphuric acid erm... Yeah I will do now.
[John:] Okay or nitric if that's easier whichever one
[Andrew:] Yeah.
[John:] comes first.
[Andrew:] Erm N A O H no that's sodium hydroxide
[John:] The ones ending in O H
[Andrew:] Yeah.
[John:] are the alkalis
[Andrew:] Yeah.
[John:] Okay. The acids all start with
[Andrew:] I know it it's just that
[John:] with an H
[Andrew:] Yeah.
[John:] well you know we put the H first....
[Andrew:] H two S O four.
[John:] Brilliant. Okay?
[Andrew:] Yeah.
[John:] So H two S O four... right before we go any further with that H two S O four how many Hs in it?
[Andrew:] Two.
[John:] And how many Ss?
[Andrew:] One.
[John:] Good. One S. If we'd put brackets round
[Andrew:] Four Os.
[John:] the whole lot and then a four down there it would have been four but four Os only one S. Right.
[Andrew:] Okay.
[John:] Plus erm plus you could do ammonium erm now let's have a... calcium erm hydroxide.
[Andrew:] Calcium... that's C A two plus C A and that's a double positive
[John:] Right so
[Andrew:] so I'm gonna need two hydroxide.
[John:] Two hydroxides cos they're just a single negative.
[Andrew:] Which is O H.
[John:] O H now how many of those do you want?
[Andrew:] In brackets.
[John:] Great.
[Andrew:] And there are two.
[John:] Right right. you got the the O H is the bit you want twice so write it down put the brackets round it and then the two.
[Andrew:] Right. Hydrogen is positive.
[John:] Right.
[Andrew:] So that's positive. The sulphur sulphoxide
[John:] Sulphate.
[Andrew:] sulphate is a double negative.
[John:] Yeah sulphoxide was a good sort of
[Andrew:] And then I'm I'm a bit
[John:] Any of the 'ates any of the 'ates have got oxygen in
[Andrew:] Yeah.
[John:] in as well. So nitrate has got nitrogen and oxygen in it.
[Andrew:] The calcium... is a double positive. [whispering] []... And the O H is a... that'll be a double negative cos there's two of them No
[John:] Well now no no
[Andrew:] no no cos they're joined together that'll be a single negative.
[John:] O H O H is is a single negative but keep it inside the bracket [whispering] that's it [] and don't forget the two applies to everything inside there so
[Andrew:] Yeah.
[John:] we'll finish up with two negatives one from each O H.
[Andrew:] So... hydrogen
[John:] Right.
[Andrew:] reacts with the O H.
[John:] Yeah.
[Andrew:] And the S O four reacts with C A the calcium. So hydrogen... there's two of this hydroxide.
[John:] Two hydroxides so if you just write twice just write O H negative and then another O H negative.
[Andrew:] Yeah H... two... er no yeah I need H two O H... mm no two H two O.
[John:] Brilliant. Two H two O yeah. What we've got... if you write them out separately
[Andrew:] Yeah.
[John:] just to show what's happening. What have we got we've got two lots of H positive okay there's one H positive and there's another H positive.
[Andrew:] Yeah.
[John:] They're two separate it's H positive times two. What have we got here O H negative times two. Two lots of O H negative. Right now we're just back onto what we were doing here. One H positive one O H negative gives you... the H two O we've got two lots of that so we're going to get two H two O.
[Andrew:] Mhm.
[John:] And you've even and you've even balanced the equation as you've done it. And then what's left over.
[speaker001:] Right.
[Andrew:] Two H two O and now we've got the sulphate... and the calcium.
[John:] Mhm.
[Andrew:] And they're both double negative and double positive.
[John:] That's right.
[Andrew:] So it's C A S O four.
[John:] . So that's that's something that you've never done before an equation you've st... perhaps never even heard of calcium sulphate. But just from that little table which you'll get used to as work through them, you can work what would happen. So you can
[Andrew:] Mm.
[John:] work out what would happen for any of the any of the acids with any of the alkalis.
[Andrew:] Mm.
[John:] Erm do you want to try another one?
[Andrew:] Yeah yeah.
[John:] Yeah. It's the the the time to do another one is when you think, Oh yeah there's no problem here I've definitely got this. then it's a good idea just to do another one and make sure. Okay sh so erm let's try... mm say stay with erm sulphuric acid, so sulphuric acid plus... erm...
[Andrew:] Sulphuric er yeah.
[John:] Sulphuric acid plus what shall we have out of this lot.... Erm
[Andrew:] [whispering] []
[John:] how about ammonium... erm hydroxide.
[Andrew:] H... H... two S... O four
[John:] Yeah.
[Andrew:] plus what was it again? erm
[John:] Ammonium hydroxide.
[Andrew:] Ammonium N H four... er
[John:] O H
[Andrew:] Right. I know that's a positive... that's a double negative... the N H four a positive... and that is a negative. So again the H two and the O H
[John:] Right.
[Andrew:] make er H two O
[John:] Okay.
[Andrew:] [whispering] H O [] plus
[John:] What have you got left over?
[Andrew:] the S O four and the N H four that's a double negative and that's a single positive it's going to be... two N H four S O four... no erm [whispering] let me think about it again [] er...
[John:] what's wrong with
[Andrew:] S O four N H two N H four....
[John:] It's you you were
[Andrew:] Yeah.
[John:] you were right the first time.
[Andrew:] Right.
[John:] So it's N H four
[Andrew:] Two N H four I said.
[John:] You're going to have two lots of N H four right. Let's let's say we were doing Right now what do you mean by that? What does this two apply to?...
[Andrew:] Erm... the N H four so brackets
[John:] Let's
[Andrew:] with the two afterwards.
[John:] Right brilliant.
[Andrew:] So S O four bracket N H four two.
[John:] Right so it's the right way round N H four... N H four twice so N H four two
[Andrew:] [whispering] S O four. []
[John:] S O four.
[Andrew:] Right.
[John:] Erm when you put two H two O what did you mean? two H two O wherever it was there it is.
[Andrew:] Two waters.
[John:] Yeah and how many hydrogens all together?
[Andrew:] Er one oh no two four hydrogens.
[John:] And how many oxygens?
[Andrew:] Two.
[John:] Right so if you put the number in front, it's as though you've got brackets around the whole lot. I mean
[Andrew:] Mm.
[John:] really you should have brackets round the whole lot but we don't bother to put them.
[Andrew:] Yeah.
[John:] should do it's a bit sloppy in the notation convention.... So if you just wanted two hydrogens when you put it down here. If you just wanted two N H fours you'd put it down here. Okay?
[Andrew:] Yeah.
[John:] So I think you've definitely got that
[Andrew:] Right.
[John:] very well on that. Erm nitrates, sulphates and... what else any other 'ates that you've heard of?
[Andrew:] Erm nitrates, sulphates...
[John:] Okay now just stick with those.
[Andrew:] I'm just think I I'm just thinking.
[John:] Don't worry.
[Andrew:] Er...
[John:] There's there's one in there.
[Andrew:] Yeah I'm just thinking.
[John:] another ate. And it's not it's not the same as these as these it's not
[Andrew:] Chlorate.
[John:] Chlorate yes there is a chlorate. Erm there's one down there.
[Andrew:] Carbonate.
[John:] Carbonate which is not quite the salt... not the sort of thing you get from an acid normally like sulphuric, sulphuric acid give you the sulphate. What's the special thing about carbonates and acids? I mean is a carbonate... erm an alkali?...
[Andrew:] Erm... no.
[John:] What happens when you drip an acid on a carbonate?...
[Andrew:] Don't know.
[John:] Do you know any carbonates?... Are you warming up?
[Andrew:] I'll just I'll just
[John:] So what happens when you drip acid onto a carbonate? Do you know any carbonates.
[Andrew:] Not really no. Well I probably do but.
[John:] Okay er have you come across calcium carbonate?
[Andrew:] Yeah....
[John:] What's that look like?
[Andrew:] Erm...
[John:] Is it normally a solid or a liquid or what?
[Andrew:] a liquid? No no erm it's a solid....
[John:] Okay, what sort of rocks have you come across?
[Andrew:] Erm erm marble chippings.
[John:] Marble chippings okay so what happens when you drip acid onto marble chippings?
[Andrew:] Er you told me last week
[John:] [cough] [LAUGHTER]
[Andrew:] remember but I can't remember.
[John:] Er have you ever seen it done?
[Andrew:] No.
[John:] Er
[Andrew:] I may have been absent or something.
[John:] Right okay. What often happens when you drip acids onto things?
[Andrew:] They react.
[John:] React maybe it's carbonates they
[Andrew:] Effervesce
[John:] Yeah effervesce they fizz a bit. What's happening?
[Andrew:] Er they're producing gas they're giving off
[John:] Okay what gas?
[Andrew:] Carbon dioxide.
[John:] Right.
[Andrew:] Mm.
[John:] So acid plus carbonate gives?
[Andrew:] Er... carbon dioxide.
[John:] Right and probably a few other things.
[Andrew:] Yeah.
[John:] Let's see if we can work out what it is. So let's pick a nice simple acid. The choice is yours.
[Andrew:] Erm
[John:] Which is the easiest one to play with?
[Andrew:] H C L.
[John:] Yeah H C L good choice plus and we'll pick an easy carbonate, er we'll pick the one that we normally use... calcium carbonate.
[Andrew:] Which is C A... erm and carbonate is C O three C A C O... now that's a positive negative the calcium is a double positive double nega positive yeah. And the C O three is a double negative.
[John:] Right.
[Andrew:] Right hydrogen and the carbonate so there's going to be H brackets two C O three yeah?
[John:] Okay well maybe maybe. It's a good try.
[Andrew:] Erm the chlorine and the calcium it's a double positive Er
[John:] Ah you remembering anything? Go on carry on
[Andrew:] I could write two H C O three
[John:] Erm well what's the difference between H two C O three and
[Andrew:] Er
[John:] two H C O three.
[Andrew:] that's two of H C O three.
[John:] Right right
[Andrew:] H two is just two of H.
[John:] Right so there i they're not the same compound at all. You can't just
[Andrew:] No no.
[John:] swap one for the other. So what's what's happening with the chlorine then?
[Andrew:] Er two C A... yeah.
[John:] Okay. Now we usually write the metal first.
[Andrew:] Yeah.
[John:] So we'd have calcium chloride
[Andrew:] Yeah so I'll rearrange it
[John:] Okay how would you write that? Just rearrange that.... Right Okay well that's quite possibly what does happen. Now go to the C L, it's just one element, we don't need the brackets it wouldn't be wrong to write the brackets round it but we don't usually bother.
[Andrew:] No.
[John:] You can just write C A C L two
[Andrew:] Right.
[John:] for that. Now this thing H two C O three erm so you've tried the reaction, you've tried these different compounds
[Andrew:] Mm.
[John:] pull 'em apart shove 'em back together again see what you can make. And you've made this thing, hydrogen carbonate
[Andrew:] Yeah.
[John:] and calcium chloride. The calcium chloride's definitely going to get formed.... But we decided that you get carbon dioxide.
[Andrew:] Oh yeah.
[John:] Right so maybe this is an intermediate stage, we don't know but we know carbon dioxide comes out of it. What would happen if you took carbon dioxide out of this? What'do
[Andrew:] Mhm.
[John:] you know the formula for carbon dioxide?
[Andrew:] Er di is two isn't it?
[John:] Right good.
[Andrew:] So it's carbon which is C
[John:] Right.
[Andrew:] C O two.
[John:] Okay so just re write C O two underneath it.
[Andrew:] [whispering] C O two. []
[John:] Now if you took C O two out of that, what would you have left?
[Andrew:] You're left with H two O... er so it's
[John:] Right.
[Andrew:] H two O plus C O three
[John:] plus C O two. Right
[Andrew:] Yeah.
[John:] Yeah.
[Andrew:] plus C A
[John:] C L two. No you don't need the brackets
[Andrew:] Yeah.
[John:] it's better without the brackets they'd probably accept it with. Okay so this was worked out... not really knowing anything about what's going on here... we've got that and that go together what would happen well pretty good bet that you'd get this calcium chloride cos that seems to form pretty easily.
[Andrew:] Mhm.
[John:] the other reactions we've had.... calcium hydroxide hydrogen chloride you get calcium chloride formed and you got this thing well it's quite likely that this does form initially, but it doesn't last very long and it's not very stable and it
[Andrew:] Right.
[John:] splits up... splits up into carbon dioxide and water.
[Andrew:] Mm.
[John:] Erm and that's it we've... sorted out the reaction. So just going back to these 'ates, sulphate has got sulphur and oxygen in it, a carbonate has got what?
[Andrew:] Er carbon and
[John:] and
[Andrew:] oxygen.
[John:] A nitrate has got?
[Andrew:] Nitrogen and oxygen.
[John:] Now a chloride
[Andrew:] Chlorine and
[John:] Just the the metal and the chlorine so sodium chloride would just be N A and then C L. Chlorate would have...
[Andrew:] Chlorate... yeah chlorine and... oxygen.
[John:] That's it so there is a system behind all these weird names [LAUGHTER]
[Andrew:] Yeah.
[John:] there's a bit of a system. Erm once you sort of crack the code and get into it, things you've never heard of when they come up you when you know the system you think, Oh well I know what I know what it means by that. So if someone said erm bromate... or bromide say what's the difference between calcium bromide and calcium bromate, what the difference be?
[Andrew:] Bromide is just the... bromine with the
[John:] Yeah.
[Andrew:] metal, bromate is bromine with the oxygen.
[John:] Good so it might be it might be something like B R O three or B R O or B R O two something like but it would have oxygen to go with it. So you're building up now I think a good understanding of the... er terminology
[Andrew:] Right.
[John:] and a good understanding of the the systems and putting these numbers in the equations.
[Andrew:] Yeah.
[John:] So as you feel happier with that, you'll b more able to play with them. But unless you do play them
[Andrew:] forget it again.
[John:] exactly, it'll be cos we looked at this last week as you said at the end what happens dripping acid onto onto chips now... the things to know about acids,... bases and salts. A metal plus an acid what happens?
[Andrew:] A metal and plus an acid.
[John:] Drip metal onto an acid I'm sorry [LAUGHTER] acid onto a metal []. Right.
[Andrew:] think that might be a bit difficult er
[John:] It might be a bit awkward if you it might be highly reactive if you dropped molten metal onto it.
[Andrew:] Erm it reacts and produces carbon dioxide. Mm would it, no... a metal with an acid.
[John:] It's a metal erm...
[Andrew:] Erm it effervesces.
[John:] Right so there's a gas given off which is?
[Andrew:] Carbon dioxide
[John:] [pop]
[Andrew:] Hydrogen.
[John:] Okay right so there's a s there's a system to what's going on with the acids and it's not just one acid like hydrochloric most of the acids will do it some of them do it very readily some of them you have to get the conditions right often you have to get the temperature high to make it to make the reaction go but a metal plus an acid erm... there's a typical one zinc H two S O four gives zinc sulphate and the hydrogen.
[Andrew:] Yeah.
[John:] And you can think of that pretty easily if you look at your table erm just write down with the... charges on the the ions what H two S O four looks like.
[Andrew:] [whispering] H... two S O four. []
[John:] right erm what's the charge on that H?
[Andrew:] Positive.
[John:] Right good.
[Andrew:] Er double negative.
[John:] Yeah great how did you work that out?
[Andrew:] Er... the Hs are positive.
[John:] Right.
[Andrew:] Yeah and there's two of it so that
[John:] Good so that was I like that because you worked it out you didn't look it with table you
[Andrew:] Yeah.
[John:] Good. So it's H two S O four plus erm a metal erm... chose zinc then shall we try it no we'll use zinc.
[Andrew:] Yeah.
[John:] have you got it in here? No.
[Andrew:] No.
[John:] Okay we'll use erm
[Andrew:] Yeah zinc ion
[John:] Right.
[Andrew:] Z N two plus.
[John:] Right. thought it should be in there cos it's normally... Okay now all that happens here if you if you think of it going back to the picture with the the magnets or the electrostatic charges or or bonds whatever you like to think of it.
[Andrew:] Yeah.
[John:] You've got an S O four with two bonds on it and it's holding on to a hydrogen
[Andrew:] Yeah.
[John:] in each one. And the zinc comes along and pushes the hydrogen out, it says, Hang on I want that sulphate.
[Andrew:] Yeah.
[John:] and it displaces the hydrogen and that we that's why we describe it the the zinc displaces the hydrogen from the acid. So zinc sulphate gets formed the zil the zinc just goes in in place of that H two.
[Andrew:] So it becomes Z N S O four.
[John:] And the two Hs that got pushed out
[Andrew:] H two yeah?
[John:] Yeah. H two and the charge... erm now ah ah hang on yeah this is this one is a bit tricky because that is not a zinc ion that's zinc just on its own so it's just Z N.
[Andrew:] Right.
[John:] Erm it wants to be a Z N double positive and go with the sulphate
[Andrew:] Yeah.
[John:] if you like so it pinches the two positive charges off the hydrogen cos in these equations the charges must must balance as well so that if you just cross the double positive out... you need to you can't write it in but you need to remember that it wants to become a double positive given
[Andrew:] Yeah.
[John:] the chance. So the zinc comes along pushes the hydrogen out takes its two charges off it as well
[Andrew:] Right.
[John:] and you're left with H two. So that's the first sort of reaction with with acids. A metal plus an acid and most of the metals and most of the acids' ll give you hydrogen. Some of them you remember the table we had a long time ago showing the reactivity of different elements, particularly the metals when we were looking at metals. Erm some metals are much more reactive than others.... I mean some some metals with... an acid... a fairly weak acid will give you hydrogen, some metals will give you hydrogen just with s water, or with steam. And some of them it's it's hard to get them to go so but in general any of the fairly reactive acids and any of the fairly reactive metals they're going to give you a salt and hydrogen. So metal plus acid gives you a salt and hydrogen. And you can do that. Then we've got... a base plus an acid, what's the difference again between a base and an alkali?
[Andrew:] A base
[John:] Mm.
[Andrew:] is neutral... no a base [sigh]
[John:] Is an alkali a base?
[Andrew:] Yeah.
[John:] Yeah okay.
[Andrew:] A base
[John:] So what's so special about an alkali that's not quite a special about a base.
[Andrew:] Erm erm
[John:] An alkali is a base but a base isn't an alkali.
[Andrew:] [LAUGHTER]
[John:] Hey?
[Andrew:] Yeah.
[John:] Erm an alkali is contained in the base family but it's got a special property.
[Andrew:] Erm
[John:] It's a fairly simple physical property actually... but they're they're soluble.
[Andrew:] Right.
[John:] So
[Andrew:] Mm.
[John:] But this thing we've been doing with an acid and an alkali, most of the bases will do it as well,
[Andrew:] Yeah.
[John:] so let's try that one. Now the base is erm most of the oxides are bases the metal oxides so what would magnesium oxide look like? And what's going to happen if we get it to react with H two S O four? So try that one H two S O four... plus magnesium oxide what's that going to be?...
[Andrew:] M G... Oxide
[John:] Is?...
[Andrew:] So that's a double positive... a double negative that's a... positive... double negative... so... H two and the O so that's gonna be... that'll be a double positive because there's two of it wouldn't it?
[John:] It's it's well
[Andrew:] Yeah.
[John:] Erm
[Andrew:] You wouldn't write it like that but
[John:] you'd write it as a single positive okay now because there's a two
[Andrew:] But because there's two of it
[John:] down there you've got two
[Andrew:] Yeah.
[John:] negative two positive
[Andrew:] That's
[John:] hooks on it
[Andrew:] H two O plus S O four... erm that's a double negative so the goes there so... magnesium M G S O four
[John:] Let's have a look. Oh that's a [LAUGHTER] shame. []
[Andrew:] What?
[John:] [LAUGHTER] was going to say check it in the book but I gave you wrong one. [] Never mind.
[Andrew:] Okay I'll do the other one
[John:] Okay check it yeah okay try the other one then. Erm an easier one in fact. Erm magnesium oxide with hydrochloric acid.
[Andrew:] M G oxide which is O right with
[John:] Hydrochloric acid.
[Andrew:] H C L and that's a double positive
[John:] Right.
[Andrew:] double negative.
[John:] Good.
[Andrew:] That's a single positive
[John:] Right.
[Andrew:] that's a negative.
[John:] Right.
[Andrew:] Right.
[John:] And what's going to happen what was the first way you can see.
[Andrew:] Magnesium chloride
[John:] Well try the... the one you tried in the first equation
[Andrew:] Oh yeah.
[John:] we did.
[Andrew:] Oxygen and a hydrogen.
[John:] Right so what have we get we've got one O negative
[Andrew:] So that'll be H
[John:] O erm
[Andrew:] two O.
[John:] Yeah that's the H two O. Where did the two Hs come from you've only got one there?
[Andrew:] Er you'll add another.
[John:] Okay put a put a two in front now. And what's that going to give you?
[Andrew:] Two that's going to become a double.
[John:] So it's going to give you two Hs and two C Ls.
[Andrew:] Two C Ls so that'll be H two O plus magnesium chlorine so that's a... M G C L two
[John:] Brilliant go on see if that's well I'm saying so see if that's what it gives in the book.
[Andrew:] M G O
[John:] It just says it's aqueous but [clears throat] but I mean when it when it when it happens
[Andrew:] Yeah.
[John:] because magnesium chloride is soluble it'll be dissolved in the water and you'll finish up with a solution of magnesium chloride. That's it so... metal and acid gives what?
[Andrew:] A metal and an acid gives erm... er water and
[John:] This is the one that doesn't give water.
[Andrew:] Oh yeah er
[John:] What did the zinc do to the hydrogen?
[Andrew:] Carbon dioxide and
[John:] Hang on hang on metal and acid say think of the zinc and which acid was it we used H two S O four, what did the zinc do to the hydrogen?
[Andrew:] Er it pinched its
[John:] good go on it what did it do?
[Andrew:] Right it pinched its positives its electrons.
[John:] Right it pinched its place and it pinched its charge, it displaced it it pinched it out of its nice cosy relationship
[Andrew:] So you get hydrogen.
[John:] and it liberated the hydrogen okay. So that's an acid plus a metal, now an acid plus a base which is this one we've just done, a metal oxide the metal oxides are bases, er you can think of them as being alkaline, we call it basic but very very similar sort of thing to alkaline okay so what happens with a base and an acid?
[Andrew:] With a base and an acid
[John:] Well what happens with an acid and an alkali?
[Andrew:] Er [whispering] acid and alkali [] er it gives a water and sal.
[John:] Right great and what happens what seems to be happening with a base and an acid or an acid and a base?
[Andrew:] Erm gives off hydrogen... ah no gives off
[John:] It gives you well this is
[Andrew:] erm
[John:] this is one that you did here.
[Andrew:] It gives off water.
[John:] This is one you did here yeah you get water and?
[Andrew:] Er... er the metal chloride magnesium chloride
[John:] in this case in this case you got a chloride if you'd used sodium you would have got sodium chloride which is?
[Andrew:] Er... Oh right salt.
[John:] So this is magnesium chloride is also a?
[Andrew:] Er salt.
[John:] Right so we tried
[Andrew:] couldn't eat it though.
[John:] acid and a base
[Andrew:] Mm.
[John:] acid and a base and we get salt and water, try alkali and a base you get salt and water so they're very similar reaction, the base and the acid and the alkali and the acid. They're the same sort of thing they're neutralizing each other. And the other one with the carbonate what happened then? The one you
[Andrew:] Er.
[John:] worked out yourself.
[Andrew:] The carbon which one was that? erm cos there's so many of them now I'm getting a bit
[John:] I know and I'm trying to pile them up now and let you see the patterns so these
[Andrew:] The carbonate I can't remember what it is I'm getting confused I
[John:] okay Right you mentioned it a few minutes ago you suggested that this thing was formed.
[Andrew:] Which one wa I I can't remember what I sa I was saying a f a lot of things a few minutes ago.
[John:] Right okay okay carbonate. What's the er what's the symbol for carbonate?
[Andrew:] Er C C C C C O?
[John:] Yeah C O?
[Andrew:] Two.
[John:] Three.
[Andrew:] Three yeah.
[John:] C O three and what did you take out of that?
[Andrew:] An O... no C... ah [LAUGHTER]
[John:] Let's go back to where you did it here. What you did was you tried H C L plus calcium carbonate.
[Andrew:] Yeah.
[John:] Okay and you sorted this out very nicely... what was going to happen and what you'd have left over. Right so you got your calcium chloride out and then you got this H two C O three. Which we said do [tape change] left over.
[Andrew:] Erm er carbon dioxide.
[John:] Right so you looked at this H C L plus C A C O three quite messy.
[Andrew:] Yeah.
[John:] What can we get out of this? Mm can't see any water there can't see any H and O H.
[Andrew:] Yeah.
[John:] But there's our old friend calcium chloride right.
[Andrew:] Yeah.
[John:] You take calcium chloride out, what have you got left? You've got this H two C O three.
[Andrew:] Yeah.
[speaker001:] Hi.
[Andrew:] Thanks.
[speaker001:] Hi... some refreshment.
[John:] Lovely.
[speaker001:] Don't tell me you don't like them.
[Andrew:] There's not a lot is there?
[speaker001:] [LAUGHTER] Do you what more? You've you've been scratching then? Oh useless. [shouting] Come on Charlie out. []
[Andrew:] go on out out
[speaker001:] [shouting] Out. []
[Andrew:] out.
[John:] [shouting] he said he can't hear you with that on [] [LAUGHTER]
[Andrew:] Yeah he can.
[John:] Right. Got an ear problem?
[Andrew:] Erm well he split his tail the end of it.
[John:] Yeah I saw his tail was bandaged.
[Andrew:] So we had the end cut off and to stop him ripping the bandages off we
[John:] Ah.
[Andrew:] wrapped it up.
[John:] Mm.
[Andrew:] The vet wrapped it up but he also had a little thing on his ear so he cut that out as well and he's gonna wear the collar to stop him scratching his ear and to stop him biting his tail. cos he's
[John:] been in a fight has he
[Andrew:] No erm it was just it was just like a little er spot on his ear and the vet sent it off to find out what it was
[John:] Mm.
[Andrew:] and he cut it out and stitched it up so.
[John:] Right. Okay meanwhile back at the carbonates so you've sorted out your calcium chloride and you've got this horrible looking thing H two C O three.
[Andrew:] Right.
[John:] But we know... this is marble chippings you know you were getting this carbon dioxide off. How could you tell it was carbon dioxide what tests c... could you do to it?
[Andrew:] Erm... if it's carbon dioxide it'll react with lime water wouldn't it.
[John:] Yeah.
[Andrew:] Make clear lime water cloudy.
[John:] Right that's it makes it milky. And it will put out a glowing splint or something. So if there w well we've got to get carbon dioxide out of this somehow cos we know carbon dioxide is given off. So you're doing a bit of detective work here, what must be happening in this? Well let's take carbon dioxide out of that and what do you get? Well out of that you've got all the makings there of carbon dioxide and water. So
[Andrew:] Mm.
[John:] gives us the other thing that happens with them that er an acid plus a carbonate gives you carbon dioxide as well as a salt and water.
[Andrew:] Right.
[John:] And that's that's about it for the acids. It also brings in the bases the the basic the bases and the alkalis. If you know that lot just there, you can probably get through about ooh eighty percent of your chemistry.
[Andrew:] Yeah.
[John:] At least seventy five percent you can work out well what have we got we got an acid or a base or a carbonate or what, and does it fit any of the I mean there aren't many patterns, there's metal acid, what does that give?
[Andrew:] Metal and acid.
[John:] Yeah.
[Andrew:] Er carbon dioxide... no er oh I'm getting confused now there's that many of them that
[John:] I know I know I know but I want to just keep going round the lot.
[Andrew:] Metal and an acid
[John:] It might help if you write them.
[Andrew:] Nah, I don't think it is I l it's just remembering they're all different and I
[John:] Right they're all different but they're similar enough to be a bit confusing. So right okay okay
[Andrew:] It effervesces with it and it gives off... Oh shit
[John:] Okay right
[Andrew:] Can I look back and
[John:] No no no no no work it out
[Andrew:] Oh fucking hell.
[John:] work it out.
[Andrew:] It's getting too confusing I've got to try it cos if I just
[John:] yeah yeah no no you've
[Andrew:] keep on working it out I won't remember it.
[John:] So you've got what have we got we've got a metal the one we used was zinc
[Andrew:] Yeah.
[John:] Z N plus an acid let's use H C L
[Andrew:] H C L.
[John:] and what happened remember what happened what what did well what what's going to get formed with zinc... and chlorine about?
[Andrew:] Zinc chloride.
[John:] Right okay. Take zinc chloride out of that take the zinc and the chlorine away and what have you got left with?
[Andrew:] Hydrogen.
[John:] Okay.
[Andrew:] Yeah.
[John:] So you didn't remember it you worked it out. Now you you're very keen on remembering everything... you can't remember everything
[Andrew:] Yeah because if I work it out I'll just know that i it made so and so but I won't know that it gave off that I'll just remember that it made like zinc chloride or something I won't remember if i I'll just remember the symbol I won't even remember the symbols but I'll just know that I can work it out if I needed to. Not I won't remember the answer.
[John:] Okay I mean the question on the paper might well be, What happens when a metal reacts with an acid.
[Andrew:] Yeah.
[John:] Not any particular one so then you've got to think well I don't know can't remember well let's try it what would happen let's try zinc maybe you'll vaguely remember we tried zinc and hydrochloric
[Andrew:] Mm yeah.
[John:] What would happen well you're almost certainly going to get the zinc chloride and what have you got left, hydrogen ah. So what happens with any acid and any metal with a mes a metal and an acid you're going to get a salt and hydrogen given off. So this is
[Andrew:] Yeah.
[John:] this is your way of working back rather than try and remember every little detail because a lot of them are similar, easy to get confused between them but you think well hey what would happen, what happens with an acid and a base, what happens with an acid and an alkali, now those two are virtually identical they they are more or less identical. What what
[Andrew:] Mm.
[John:] happens there?...
[Andrew:] With an acid and a base.
[John:] Well the easiest one perhaps is what happens with an acid and an alkali.
[Andrew:] Erm you get a water and a salt.
[John:] Right now you didn't need to go did you need to go back to remember any
[Andrew:] No.
[John:] specific ones?
[Andrew:] No.
[John:] No and the same thing happens with a base
[Andrew:] Water and salt.
[John:] Water and a salt. And then the other thing is what happens with a carbonate and an acid?
[Andrew:] Erm carbon dioxide.
[John:] Right and?
[Andrew:] Er hydrogen no [whispering] carbon dioxide [] water.
[John:] Yeah and?
[Andrew:] And? [LAUGHTER]
[John:] [LAUGHTER] you've you've worked it you've worked it out over here and yeah and. What did you do you got this horrible looking thing and we said oh that doesn't happen because we know we've got carbon dioxide
[Andrew:] Oh er you mean
[John:] But you'd already taken out
[Andrew:] It made Yeah I know it made that but I thought you just wanted to know what it gave off.
[John:] Oh okay what every everything that's made so
[Andrew:] It's calcium chloride.
[John:] Right so there's a salt and the carbon dioxide
[Andrew:] And the a
[John:] and the water.
[Andrew:] Water.
[John:] So if you want to just sort of remember them all, as a table... we've got sort of say acid... plus... metal and see what happens see what's given off, well we get a salt a lot of the time don't we and we
[Andrew:] Yeah.
[John:] get water a lot of the time so erm salt,... water,... hydrogen,... carbon dioxide.
[Andrew:] Yeah.
[John:] Can you remember what happens with the metal?
[Andrew:] Erm
[John:] acid and the metal what did we get?
[Andrew:] Acid and metal it gives off... hydrogen.
[John:] Right okay so it's hydrogen and?
[Andrew:] Erm... salt.
[John:] Right. Brilliant. Acid plus an alkali that's about the easiest one.
[Andrew:] That's er salt and water.
[John:] Right. Acid plus alkali gives you salt... and water.
[Andrew:] Yeah.
[John:] And.
[Andrew:] Acid and a base.
[John:] Good.... And that gave you what?
[Andrew:] Er salt and water.
[John:] Right and acid and perhaps the most awkward one the carbonate. Which gave?
[Andrew:] Right er hydrogen
[John:] The carbonate carbonate carbonate
[Andrew:] Oh yeah carbon... dioxide
[John:] Dioxide okay.
[Andrew:] Yeah carbon dioxide and the water that was it I was thinking I saw the H two yeah
[John:] and and the water yeah and the water and the
[Andrew:] and salt.
[John:] salt.
[Andrew:] Right.
[John:] Okay so that's your... table of what goes on. Now you can look at that and sort of chant it out to yourself and learn that as a table or learn it visually or vaguely remember some of it and fill in the gaps by going back, What happened when we tried when we dripped ac acid on a metal?
[Andrew:] Yeah.
[John:] Hydrogen. What happened when we dripped acid on marble chippings on a carbonate? What did happen?
[Andrew:] Er marble chippings on effervesces it gives off carbon dioxide.
[John:] Carbon dioxide okay what happens with the old standards the alkalis?
[Andrew:] Er water and a salt.
[John:] Yeah and the same for the bases.
[Andrew:] Right.
[John:] So I reckon you've got that all sorted out. You know the sys that I mean that's the system this is say this is the key to a good getting on for eighty percent
[Andrew:] Yeah.
[John:] of the chemistry you need. Erm you'll be able to look at it and say, Well is it a is it an acid and a base, acid alkali, acid metal, acid carbonate. If it is even if you've never heard of them before you know sort of funnium carbonate or something
[Andrew:] Yeah.
[John:] You're going to think well I know what will happen, we'll get if you drip hydrochloric acid on it you'd get funnium chloride [LAUGHTER] water and [LAUGHTER] carbon dioxide. []
[Andrew:] Yeah. Right.
[John:] You'd need to know
[Andrew:] Yeah.
[John:] what the valency is to make up this formula you could do the same if it was if someone told you it was an some unknown So if it's an unknown compound and I drip Let's say it was unknown compound and I dripped hydrochloric acid on... and I got carbon dioxide given off... yeah
[Andrew:] Yeah.
[John:] and I got calcium chloride and water formed what was it that I was dripping onto?
[Andrew:] Er and you got calcium
[John:] I got I got carbon dioxide given off
[Andrew:] Yeah.
[John:] so it must have been?...
[Andrew:] Erm... a carbonate.
[John:] It must have been Good it must have been some sort of carbonate, and the salt that was formed was from the hydrochloric acid was... calcium chloride, so it must have been?
[Andrew:] Calcium carbonate.
[John:] So I mean if I I might have magnesium carbonate... and I drop hydrochloric acid on
[Andrew:] Yeah.
[John:] what would I get?...
[Andrew:] [whispering] Magnesium carbonate []
[John:] Magnesium carbonate drop hydrochloric acid onto that.
[Andrew:] Magnesium hydroxide
[John:] Magnesium... salt of hydrochloric acid?
[Andrew:] It's it's all too much I'm getting a bit confused now it's
[John:] Okay okay okay go back so what you need is a when you get when you get
[Andrew:] I'm I'm trying to do too much at once now it's
[John:] Okay okay When you get confused when you get lost you've got to go back and find your direction again so carbonates carbonates
[Andrew:] Yeah but it's not it's not, Oh I don't what direction I'm heading in. I'm trying to do too many things at once and I'm getting, Oh oh is it. and this kind of thing it's getting er I just think I'm going to end up more confused by trying to do it all at once than if I concentrate on one thing at a time. Cos I'm going to be getting it mixed in future now.
[John:] okay let's say let's say we're looking at carbonates
[Andrew:] Yeah.
[John:] Right we're we're dripping this acid on a carbonate erm and you know you've worked out you've remembered, Carbon dioxide and water and a salt. but what on earth is the salt? Well they all give a salt. Which is the easiest one to remember for working out the salt out of these four here?
[Andrew:] Which is the easiest one to remember
[John:] The easiest equation if I said, Write down the equation for one of these. which one would you go for as being the easiest the one you're most sure about?
[Andrew:] Er... er the acid and an alkali.
[John:] Right acid and alkali okay so try it. H C L plus an alkali... C A O H... is that is that balanced what's C A?
[Andrew:] Er double positive.
[John:] C A double positive okay so how many O Hs will we need to go with that?
[Andrew:] Two.
[John:] Right good cos the O H is only a single negative. S
[Andrew:] You don't need brackets at the end do you?
[John:] S erm I need if I just put... C A O H two
[Andrew:] Yeah.
[John:] it would only be two Hs
[Andrew:] Right.
[John:] cos they're separate elements. Like
[Andrew:] Yeah.
[John:] each capital letter starts a new element and that would mean one C A one O and two Hs but what I is... one C A and two O Hs which is two
[Andrew:] Right.
[John:] Os and two Hs yeah?
[Andrew:] Yeah.
[John:] So I've got that lot and what's the salt? Forget about all the rest of it, we know it gives water okay.
[Andrew:] Calcium chloride.
[John:] Right now calcium carbonate... C A C O three, is that balanced up? What do we need how many do we need that's a double positive what about C O three?
[Andrew:] Er
[John:] Well have a look where's the C O three gone?... Okay
[Andrew:] Erm.
[John:] And that is a double negative so that's balanced.... Well you you wrote the equation out you worked out what was happening, that... and the you need two of those... So those two got together and the salt again was?... Yeah.
[Andrew:] Yeah.
[John:] You're you're looking at the carbonate trying to work out what on earth goes on here what is the salt when you drop hydrochloric acid onto the carbonate. Don't know but I can remember what happens with the alkali and the acid, you get calcium chloride, er it's the same. The salt is the same all the way through here. whether you're dropping it on the putting the acid to the... the alkal the the metal, the alkali, the base or the carbonate, the salt is always a salt of the acid. So hydrochloric acid always gives you the chloride, sulphuric acid always gives you the sulphate, nitric
[Andrew:] Yeah.
[John:] acid always gives you the nitrate.
[Andrew:] Yeah.
[John:] Okay and that's the so that pattern... straight the way through for all these four reactions it doesn't matter which one you do. So the salt you can remember it through going back to the acid plus alkali reaction, it's the same one you get there. Right. The base... acid base it's exactly the same, there's no difference, you're going to get the same salt and the and the water. Carbonate it's the same again just chuck in the extra C O two.
[Andrew:] Right.
[John:] And perhaps the most difficult one to remember is the easiest of the lot, the acid plus the metal cos there's none of the usual stuff, no salt no water just the hydrogen coming off.
[Andrew:] Yeah.
[John:] But it's you can I know you think it's a lot to take in
[Andrew:] Yeah.
[John:] but if once you can see it as a pattern, all this lot fit together and you're not If you learn those four reactions separately a month apart or something yeah? You're learning the same information over and over again, this lot you're learning the whole lot once it's it's as though every time you learned a word, you had to learn your alphabet all over again
[Andrew:] Right.
[John:] and didn't realize that the A made the same sound in this word as it does in that. I know it doesn't in most but but there is enough of a a tie up
[Andrew:] Mm.
[John:] to make it easier to learn that way. Now... do you still feel that it is too much for you to take all that lot in in one go, or do you think it's all it's it's it's gu it's
[Andrew:] A little bit yeah.
[John:] you know
[Andrew:] Yeah.
[John:] gelling together a bit.
[Andrew:] No I think what it is I understand it now but if you ask me in a couple of weeks
[John:] Right.
[Andrew:] I'm not going to be sure wheth whether an acid and a carbonate
[John:] Well I'll ask you every week.
[Andrew:] I might say yeah
[John:] I'll ask you every week.
[Andrew:] can I just say something but I might get an acid and a carbonate mixed up with an acid and a metal. Or
[John:] Okay.
[Andrew:] an acid and a metal with an acid and a carbonate.
[John:] But but but if you write the formula down let's say let's say you get it all wrong and I say, What happens if you have an acid and an alkali? and you say, Well I know they all give a salt so that's a safe bet, so I'll say they give a salt. erm they all give a water apart from the one that's just with the metal right, so water's a good bet. And I think this gives carbon dioxide. Let's say you're doing acid plus alkali and for some reason you think, Oh well I think it gives carbon dioxide. So I say, Okay where does your carbon dioxide come from then. Acid H C L and the standard alkali acid alkali reaction we use, what do we normally pick for the alkali? What's
[Andrew:] Er
[John:] the well known one we keep choosing?
[Andrew:] er sodium hydroxide.
[John:] Right all the alkalis, that we're using anyway, all the hydroxides are alkaline. So what's going to happen there?... They go together the chlorine and sodium go together to make the sodium chloride and the H and the O H go together and make the water. You've got no chance of making C O three out of that you haven't got the C anywhere.
[Andrew:] Yeah.
[John:] So if you want to make sorry C O two if you want to make C O two out of something you're going to at least have to have a C in it somewhere.
[Andrew:] Right yeah.
[John:] And which one of this lot has got the C in? Is it the metal, the alkali, the base or the carbonate?
[Andrew:] Carbonate.
[John:] Carbonate. Not only has it got the C it's got the C O three, take the O out of it to go with the H and we've got that C O two out. So it's a combination of sort of working at of working and that?
[Andrew:] Yeah.
[John:] to give the water. Stick to the nice simple ones like H C L
[Andrew:] Yeah.
[John:] What's going to happen? N A... plus H C L?... A straight forward metal plus an acid, what happens here?
[Andrew:] N A plus H C L right that's a metal
[John:] A me a metal plus an acid.
[Andrew:] Erm gives off hydrogen.
[John:] Right. Everyone of these, the big the one thing they've all got is a salt. So what's the salt from there?
[Andrew:] Er the... N A C L.
[John:] N A C L and what have you got left over?
[Andrew:] Er hydrogen.
[John:] H that's it. So we take twice we take two of it so that we get H two
[Andrew:] Yeah.
[John:] So with this system you'll remember bits, you'll forget bits, the bits you don't remember you can now work them out from the patterns. And each time you work it out, it's more it it becomes more er one you remember rather than one you have to work out. Till eventually I mean you ere doing it with these As you were going through here you weren't looking at this table you were working some of them out you were saying, Oh that'll be a double positive that'll be a double double negative these'll go together. The more you use it the more the system becomes natural to you.
[Andrew:] Yeah.
[John:] And you think well of course it would wouldn't it you know you're trying to you get to the stage you can believe me you get to the stage quite quickly where you can't understand why other people don't see it. [LAUGHTER] Look it's obvious this one's a double positive and that's a double negative so they're going to go together and you're left with H and O H which is going to make the water it's obvious isn't it.
[Andrew:] Yeah.
[John:] Okay so... try if you can can do you think you can do that, you can try to take those four reactions out of one group and see how related they are?
[Andrew:] Yeah.
[John:] What's what's the big thing that's common to all of them?
[Andrew:] Erm they all make a salt.
[John:] Right they all make the salt, they all make it in the same way Hydrochloric acid would make?
[Andrew:] Er water and a salt. Hydrochloric
[John:] yeah hydrochloric acid what sort of a salt would it make?
[Andrew:] Er er well mixed with what alkali?
[John:] Well say if it's mixed with erm sodium hydroxide.
[Andrew:] Er su er sulphur sulphur hydroxide
[John:] Hydrochloric hydrochloric acid... hydrochloric
[Andrew:] Er
[John:] Hydrochloric acid okay.
[Andrew:] I'm thinking about too much I just can't I'm getting totally confused now. Yeah I kn
[John:] Right right look at the pictures then don't okay stop thinking of hydrochloric acid, think of H C L. H C L
[Andrew:] Yeah but it's still making me confused I'm thinking about too much at once it's making it worse.
[John:] Okay. How how can we simplify it? Erm to work out
[Andrew:] I think I think I'm trying to do too much at once I'm going to be really confused next week.
[John:] You've decided. [LAUGHTER]
[Andrew:] No I've not decided but I know I am I've done this thing before it's
[John:] Right how much should we take out of this just to learn and concentrate on for all of next week?
[Andrew:] It's not that you're asking me, Oh well what happens if you. and I I've thought about it and I've thought about so many of them today I can't I'm getting confused at which one it is. Because you've asked me about so many of them.
[John:] Right well we're only we're looking at four different types so if I ask you which one
[Andrew:] Yeah I know it's only four different types of
[John:] Right
[Andrew:] of these
[John:] you think now
[Andrew:] but you're using so many different chemicals that it's getting more and more confusing
[John:] Alright so we'll stick to one acid H
[Andrew:] Yeah.
[John:] H C L
[Andrew:] Yeah but if you just said an acid and a so and so, but you're saying a H C L and a and it's I know
[John:] Okay
[Andrew:] I know it's still an acid but the way it's thinking about it's making me confused.
[John:] Okay okay right so an acid and an alkali what do we get?
[Andrew:] Erm a water a salt.
[John:] Right now if the acid happens to be hydrochloric acid with the C L on the end... when it makes the salt, have a look at that one,
[Andrew:] Yeah.
[John:] what's the salt going to be there?
[Andrew:] Er Chlor a C L and N A.
[John:] That's it so it's N A C L. The salts of H C L are something C L.
[Andrew:] Yeah.
[John:] Hydrochloric acid makes the chlorides.
[Andrew:] Yeah.
[John:] Yeah?
[Andrew:] Mm.
[John:] If we'd have used if we'd so that was hydrogen chloride makes the chlorides. Hydrogen sulphate H two S O four gives you the sulphates the ones that end in and what does hydrogen nitrate, nitric acid what does that one give you?
[Andrew:] Er H N O three ni
[John:] So this this let's say we're using N H
[Andrew:] Sodium nitrate is it?
[John:] Yeah it's sodium nitrate. So nitric acid because it's hydrogen nitrate gives you the nitrates. Sulphuric acid gives you the sulphates.
[Andrew:] Yeah.
[John:] Hydrogen chlorine chlori chloride H C L gives you the chlorides.
[Andrew:] Mm.
[John:] Erm we'll do I'll just get you to write that out in words and then we'll have a break
[Andrew:] Yeah.
[John:] and a a little stroll around the room or something
[Andrew:] Yeah.
[John:] because
[Andrew:] it's coming up to time now anyway so we might as well forget the break.
[John:] [LAUGHTER] Okay what time did I get here then?
[Andrew:] Quarter past.
[John:] Yeah okay then. So hydrochloric acid hydrogen... chloride
[Andrew:] Yeah.
[John:] Right plus sodium hydroxide... now what all that happens is that these two change places.
[Andrew:] Yeah.
[John:] So we then get sodium chloride and hydrogen hydroxide.
[Andrew:] Yeah.
[John:] Hydrogen hydroxide H O H well we usually write that H two O.
[Andrew:] Mm.
[John:] So if you think of the sort of the word patterns, hydrogen chloride sodium hydroxide gives you sodium chloride and hydrogen hydroxide.
[Andrew:] Yeah... mm yeah.
[John:] It's perhaps perhaps easier to see it as the as the N As and the O Hs though okay or if we did it with sulphuric acid we'd have hydrogen sulphate plus sodium hydroxide... what's that going to give us? Again they just change round they swap places
[Andrew:] Mm.
[John:] to give us sodium sulphate and hydrogen hydroxide again.
[Andrew:] Yeah.
[John:] Water H O H water. Nitric acid hydrogen nitrate plus sodium chloride... again these two... swap places and we get the sodium nitrate and hydrogen hydroxide again.
[Andrew:] Yeah.
[John:] H O H water.... That's the that's the pattern that all the acids are following. Write their names write write it like this H C L N A O H
[Andrew:] Yeah.
[John:] swap them round and there's the answer
[Andrew:] Right
[John:] That's done it. Hydrogen sulphate sodium hydroxide swap them round sodium sulphate hydrogen hydroxide hy we never say hydrogen hydroxide it's simpler to say water but if you write it as H O H then you think, Ah we've got the two Hs and the O there. Water.
[Andrew:] Mm.
[John:] And that's that's it that's the pattern for all of them for all those four reactions. So that'll
[Andrew:] Right.
[John:] the salt. Erm have you got any of your books with you?
[Andrew:] Yeah.
[John:] Erm have you got your chemistry course book that you're working from?
[Andrew:] We're we're not really working from it we're
[John:] Mm.
[Andrew:] it's just a book we have.
[John:] Okay.
[Andrew:] The
[John:] Well if you can get that we'll have a look at that and I want you to try some of these equations in it. And I want you to try them in groups so that acid alkali
[Andrew:] Yeah.
[John:] I think I reckon you could you could just do that without looking at your book couldn't you.
[Andrew:] Yeah.
[John:] Yeah?
[Andrew:] Yeah.
[John:] If someone said, Okay nitric acid and calcium hydroxide. as long as you were using this chart to work out which are single negative and double negative, what's going to happen to that one? You've got nitric acid
[Andrew:] Yeah.
[John:] hydrogen nitrate plus calcium hydroxide
[Andrew:] Yeah.
[John:] is going to give you well these two the metal and the hydrogen just swap round each time. So it's going to give you calcium nitrate and the old hydrogen hydroxide again. you you can you can look at I mean it's easier with your formula if you've got H N O three and C A O H twice... C A and that's going together. You'll need two of these... because we want two O Hs to go with those two O Hs.
[Andrew:] Yeah.
[John:] And you'll want two N O three's to go with that C A. So any of these I reckon you could work out any any acid with any alkali you could work it out.
[Andrew:] Yeah.
[John:] So have a look through your book have a very quick glance at erm if you can just at... an acid alkali one, at one side of an equation co try not to read it cover it up... write it down and leave it for a few minutes till you've forgotten if you did accidentally see what was on the other side till you've forgotten it. Erm
[Andrew:] Right.
[John:] write a few of those down, all the same type, all acids and alkali and then you just you can just bomb through those. Then try some... with bases. Yeah try a few of those erm that one... really
[Andrew:] Yeah.
[John:] you could work out any one of those at all any metal with any acid because the metal just comes in pushes the hydrogen out. So if it was hydrogen sulphate, sulphuric acid, it'll push the hydrogen out and become zinc sulphate and liberate the hydrogen. If it was hydrogen nitrate the nitric acid the zinc would push the hydrogen out and make a zinc nitrate.... Erm the carbonate perhaps the most awkward one
[Andrew:] Yeah.
[John:] but you've worked that out yourself I like that because you [cough] you went for the salt see you knew you were doing... exactly what I was saying sort of forming the pattern
[Andrew:] Yeah.
[John:] But you you don't want to you don't want to see that you're doing it that way.
[Andrew:] Yeah.
[John:] [cough] so went straight for the calcium chloride, this is the page where you did it.... Right quite an awkward one that I gave you. Hydrogen chloride calcium carbonate you put your your double and single negatives on. Well we're going to get a salt cos they all give salts. There's your calcium chloride what have we get left over we've got this we've got hydrogen carbonate and that was really should have been your answer but then you know carbon dioxide came out... so you just took it out and you got water left over.
[Andrew:] Yeah.
[John:] So that gives you this fits with this pattern acid carbonate they all give a salt... apart from the hydrogen one they all give water as well and this one gives a C O two.
[Andrew:] Yeah right.
[John:] So I do want you to try to build up as many of those as you can. Think I think the acid alkali there's no problem.
[Andrew:] Oh yeah I know but all I was saying was that much of different things
[John:] Right.
[Andrew:] in one lesson within a space of fifteen minutes
[John:] Right.
[Andrew:] that in one or two weeks time I'm going to be thin I'm going to be slightly mixed up.
[John:] Right well learn them this way then learn only the sodium hydroxide right
[Andrew:] Yeah.
[John:] and erm oh calcium hydroxide is perhaps a more interesting one but you pick one of them that you're happy with and take it through here so what would happen with let's see I mean you wouldn't actually drip sodium an acid onto sodium if you've got any sense. [LAUGHTER] Okay.
[Andrew:] Yeah I know
[speaker001:] boom.
[John:] But you should get roughly the same reaction. Erm so maybe we could we've been using sodium a lot try calcium because it's interesting cos it's got a double one a double positive negative is it?
[Andrew:] Mm.
[John:] Right. So... take them through there acid plus calcium, acid plus alkali calcium hydroxide... acid plus base calcium oxide. So the alkali any alkaline use C A O H twice, for the base C A O calcium oxide and for the carbonate C A C O three, the metal just calcium. Okay?
[Andrew:] Yeah.
[John:] So you can work through those with each of the acids. So go through with H C L.
[Andrew:] Right.
[John:] Okay.
[Andrew:] Yeah.
[John:] And just go straight through that what happens then go through again with whichever one you want to do next H two S O four? Yeah and then go through again with nitric acid. In each case you you did it this is what I like you went straight for it you went straight for the salt... on the most difficult one the carbonate. Right it's going to be calcium chloride. You got that out and you found this horrible hydrogen carbonate thing left over.
[Andrew:] Mm.
[John:] So you can do you can use exactly the same system you used on that for working out each one... and see what happens. Now are you happy with that that you can do that or do you think that's sort of overloading you?
[Andrew:] No that's fine.
[John:] I I th I'm quite sure that you can go through that because you're recognizing the patterns much more now, you're accepting more things as, Oh yeah, you don't need to tell me that I know it.
[Andrew:] Yeah.
[John:] I can feel this coming back much more rather than, Tell me that again. Why is is called a chloride? Why is is called a sulphate?
[Andrew:] Right.
[John:] So you recognize these patterns.
[Andrew:] Yeah.
[John:] Okay?
[Andrew:] Yeah.
[John:] Erm now next week you were saying something about you'd like one on Easter Monday, I won't actually be here.
[Andrew:] Mhm yeah.
[John:] Erm
[Andrew:] Some time next week I mean
[John:] You want one some time next week.
[Andrew:] I mean whatever days you give.
[John:] Right now
[Andrew:] Apart from Saturday or Sunday.
[John:] I was very pleased that you'd had a good go at that
[Andrew:] Yeah.
[John:] you'd misunderstood
[Andrew:] Yeah.
[John:] Now can you write out either now or just before I or when I've gone what you're going to do
[Andrew:] take a piece of paper Yeah I just wanna write down what you
[John:] So what are you what are you going to do?
[Andrew:] Erm
[John:] Can you remember what you're going to do?
[Andrew:] learn some of these.
[John:] Right taking calcium as the metal,... you want to write equations... for each of the four types of reaction.... Do you remember what those four types where? Or any
[Andrew:] Er
[John:] of those four types.
[Andrew:] yeah.
[John:] Go on.
[Andrew:] Er bases,
[John:] Right.
[Andrew:] alkalis,
[John:] Yeah.
[Andrew:] carbonates,
[John:] Right.
[Andrew:] erm
[John:] and the most simple one which is the hardest to remember cos it's so obvious.
[Andrew:] Yeah [LAUGHTER] erm... oh shoot what was it?
[John:] Taking calcium did we say? Yeah.
[Andrew:] Yeah.
[John:] As the
[Andrew:] Metals metals.
[John:] Just the metal
[Andrew:] Yeah.
[John:] Just the metal plus the acid.
[Andrew:] Right.
[John:] Okay? So go through use calcium go through each of the four reactions
[Andrew:] Mm. Yeah.
[John:] So use calcium hydroxide which is written on there, as the
[Andrew:] Mhm.
[John:] alkali, calcium oxide as the base, calcium itself as the metal, calcium carbonate as the carbonate. we got four types of reaction using first H C L okay so write that in using first H C L then H N O three then H two S O four.
[Andrew:] Right.
[John:] And they're all they 're they're all patterns within lots of similarities, by going through it a few times like that and when you when you've done that go through again say and with and everywhere you could write the whole lot out again
[Andrew:] Yeah.
[John:] and everywhere you've got an a C A you could put an M G and everything would fit because it's C A double positive M G double positive.
[Andrew:] Right.
[John:] You could go through again and you could put sodium instead of that M G but where you had things like M G O H twice you'd just have N A O H so you 'd have a have to do a little bit of changing about. Are you happy with that?
[Andrew:] Yeah.
[John:] You can do that. And don't forget for each for each of the acids. Yeah so it's first four H C L then H N O three then H two S O four.
[Andrew:] Yeah.
[John:] Okay?
[Andrew:] Right.
[John:] Now erm for next oh something else as well I'm not sure whether you sign this or I do it erm right what's the date is it about twenty eighth?
[Andrew:] Twenty ninth.
[John:] You can read it if you've got time.
[Andrew:] [LAUGHTER] Yeah.
[John:] I always re I wouldn't sign
[Andrew:] right.
[John:] anything without reading it. Erm what it says
[Andrew:] Yeah. I'll just read it thank you.
[John:] Okay. That's the big point there.... But you don't have to sign
[Andrew:] Yeah.
[John:] there's no compulsion to sign
[Andrew:] Oh yeah
[John:] at all by the way if you don't want anyone to It will be someone who doesn't know you will try to code up that tape into hieroglyphics which is
[Andrew:] Yeah.
[John:] then stored digitally just the
[Andrew:] Yeah.
[John:] words not your voice or anything.
[Andrew:] Just the words right.
[John:] And the
[Andrew:] Just sign it here.
[John:] It's the erm the way you stress words the way for example the way I will repeat words quite a
[Andrew:] Yeah.
[John:] bit. [LAUGHTER] And the way
[Andrew:] And the way you use and what use them for.
[John:] The way people
[Andrew:] Where I'd say right meaning I understand kind of thing but I'm not saying that's right I mean right.
[John:] Yeah people say that a lot right
[Andrew:] Yeah.
[John:] yeah yeah got it yeah yeah [LAUGHTER]
[Andrew:] Yeah Yep
[John:] All this sort of yep you wouldn't find it in the dictionary
[Andrew:] No.
[John:] it goes in now. Yep it's what people say when they
[Andrew:] It will do now in a couple of years time.
[John:] Erm okay that's great. Now erm at the moment I've got a lot to fit in
[Andrew:] I feel sorry for the poor person who has to translate it.
[John:] for next week. Oh she's very good actually she
[Andrew:] Yeah.
[John:] batters away all day putting the stuff in erm she's she trained well she
[Andrew:] I'm pretty dubious to me.
[John:] trained as a linguist. Ah but she's she's she is
[Andrew:] Yeah.
[John:] interested in it this is
[Andrew:] Yeah.
[John:] the thing. She is interested in accents and she'll listen to it and think, Ah that's someone who comes from Liverpool, er not a very not a very scouse accent but because they say
[Andrew:] I don't know you know I've been on holiday and people think I've got an amazingly strong
[John:] And you think, No I haven't. It's
[Andrew:] No I haven't they even a they even say my dad's got an accent whereas
[John:] Yeah.
[Andrew:] I would say ee hasn't.
[John:] ee hasn't.
[Andrew:] Yeah.
[John:] Erm but she will you know she'll notice that you you don't say bath and grass
[Andrew:] Yeah.
[John:] you know bath and grass. [LAUGHTER]
[Andrew:] Yeah.
[John:] Things like this.
[Andrew:] scone and scone.
[John:] well one doesn't say I don't think one says scone any more. There are good
[Andrew:] Mm there are people who have done.
[John:] Yes.
[Andrew:] Strange.
[John:] There are good things have come out if as well like
[Andrew:] Yeah.
[John:] erm I mean I did a teaching initial for foreign language course at the the university
[Andrew:] Mm.
[John:] and the thing what we found out there was sort of up to date English usage. I think I'll just take those sheets I said I would give you. So you used to say in business letters things like I should be grateful if.
[Andrew:] Mm.
[John:] Nobody really says that any more they say I would be, they don't bother saying I should
[Andrew:] Mm.
[John:] they say I would.
[Andrew:] Would.
[John:] so
[Andrew:] I mean I got that with my interview at I should be grateful if you would
[John:] Mm or
[Andrew:] I've ne I don't think I've ever heard anyone aver say it.
[John:] Well it's it's quite correct
[Andrew:] I would be grateful.
[John:] It's grammatical
[Andrew:] or I will be grateful.
[John:] Yeah it's grammatically correct
[Andrew:] Yeah.
[John:] but soon it will be appearing in a dictionary as, A bit over-formal, a bit archaic, use it if you like in a business letter but most people would prefer
[Andrew:] it's way down the I mean all these people go, Oh it's people aren't using the english language properly but if you look at the english language two hundred years ago
[John:] Exactly.
[Andrew:] it was nothing like what it is today. It's developed it changes its form and it's
[John:] Yeah.
[Andrew:] like a life-form it's
[John:] Right. they go on about Shakespeare and Chauce Chaucer but if you spoke to them the way Chaucer used to speak they wouldn't understand a [LAUGHTER] word you were saying [].
[Andrew:] they wouldn't understand Whereas we can just about understand Chaucer.
[John:] Yeah so as you say it's a it's a developing thing and the only
[Andrew:] a life-form it's growing it's spreading.
[John:] Yeah new words words come in erm you know I'm well pleased [LAUGHTER]
[Andrew:] Yeah.
[John:] That's wicked.
[Andrew:] Yeah.
[John:] It's really wicked, Oh
[Andrew:] Like a lot of old slang words from you know like a hun fifty or so back years ago are now proper words now.
[John:] Yeah they're accepted and the the language developing is developing more quickly than that so they want to get the stuff into dictionaries
[Andrew:] Yeah.
[John:] you know and
[Andrew:] I suppose it helps nowadays with things like tape recorders and so on.
[John:] And computers
[Andrew:] Yeah.
[John:] so because they will thousands
[Andrew:] You can store it easily You can use a database.
[John:] Thousands yeah exactly from all over the country and they'll put these together and they'll say well in do you know about eighty percent of our interviews people are saying yep. Nobody actually says, Oh yes I agree dear chap. [LAUGHTER] they say yep yep yep
[Andrew:] Yeah
[John:] Mhm mhm [LAUGHTER].
[Andrew:] It's not a word but
[John:] It's
[Andrew:] it will be one day.
[John:] It is a word cos it's something that people use
[Andrew:] Yeah.
[John:] a lot.
[Andrew:] It's not a recognized word.
[John:] They use it a lot more than other words that are in the dictionary but no one 's ever heard of so they want to get usage.
[Andrew:] Right.
[John:] Anyway I'd better make sure I remember that. You okay for that?
[Andrew:] Yeah.
[John:] that? 0
[Andrew:] Er somebody'll be in
[John:] Right.
[Andrew:] most evenings.
[John:] Have you any ideas now what will be a good day for you next week and what will not be a good day?
[Andrew:] Er any day apart from Monday of course
[John:] Right.
[Andrew:] er Tuesday I've got my maths tutor so apart from Saturday and Sunday
[John:] And you'll be ava you'll finish this you'll be available during the day time won't you?
[Andrew:] Yeah oh yeah that's fair enough.
[John:] So I can probably give about sort of
[Andrew:] Two o'clock if you want.
[John:] Yeah something like
[Andrew:] Yeah one o'clock two o'clock.
[John:] I've got a two o'clock slot on Tuesday next week erm
[Andrew:] Wednesday, Thursday, Friday.
[John:] Yeah I'll I'll check what I've got booked where and then I'll I'll get in touch you for next week. Er
[Andrew:] As long as it doesn't cause too much disruption for you.
[John:] [sigh] It doesn't. Erm
[Andrew:] Yeah.
[John:] I've got some students at the moment erm
[Andrew:] I suppose with Easter most people do stay I mean [tape ends]