00:13:41 the

00:13:45 solution of iodine and benzene

00:13:48 is red

00:13:50 that's number three

00:13:53 here it is

00:13:55 and it takes out some of the blue

00:13:59 you see

00:14:00 so that accounts for the color change in benzene

00:14:02 yes

00:14:03 now ethyl alcohol is one of those isn't it

00:14:06 yes

00:14:07 so it's the ether

00:14:08 ether

00:14:09 has about the same color I guess

00:14:11 a good deal of the same color

00:14:12 and that's number five

00:14:14 now what about the surprise

00:14:16 well

00:14:17 I had a

00:14:20 a

00:14:24 a

00:14:28 Perkin Elmer

00:14:32 I wanted to

00:14:34 investigate the

00:14:36 this red color

00:14:38 and the

00:14:40 the instrument

00:14:42 the spectrophotometer

00:14:49 operated out of the ultraviolet

00:14:52 so the eye is not sensitive

00:14:54 yes

00:14:56 but the

00:14:58 the astonishment was

00:15:02 that although this is a

00:15:04 a great, a very strong absorption

00:15:07 here is ten times the absorption

00:15:10 of the ultraviolet

00:15:11 yes

00:15:13 and that led to a

00:15:16 to a test

00:15:18 for a salvation

00:15:20 now that really was the first discovery wasn't it

00:15:23 of the charge transfer

00:15:24 yes it was

00:15:26 so this is one of my

00:15:36 this is way back to 1920

00:15:38 yes

00:15:39 well this made it evident

00:15:42 this is benzene

00:15:44 it has a different slope

00:15:46 the others evidently have

00:15:49 belong to a family of curves

00:15:52 they can use the same equations

00:15:55 but two different values to the

00:15:58 to the power

00:15:59 now what's next

00:16:01 what

00:16:06 it would be helpful if you leave

00:16:08 no, leave it going

00:16:10 oh, why

00:16:14 oh, ok

00:16:16 let's try it again

00:16:17 I think if you leave your hand up on the paper

00:16:19 it would be a little easier

00:16:21 1920

00:16:23 yes

00:16:24 well this made it evident

00:16:27 this is benzene

00:16:29 it has a different slope

00:16:31 the others evidently have

00:16:33 belong to a family of curves

00:16:36 they can use the same equations

00:16:39 but two different values to the

00:16:42 to the power

00:16:44 now was that

00:16:46 yes, yes

00:16:48 ok, I think you're holding

00:16:50 let's see which hand you're holding the paper

00:16:55 but the

00:16:56 you've got it right

00:16:57 the log

00:16:58 the plot against log t

00:17:00 gives straight lines except up near

00:17:03 in this place

00:17:05 there's another one here

00:17:08 here, this is it

00:17:10 ok, now the next one

00:17:12 keep the tape rolling

00:17:16 it shows how many systems

00:17:18 I kept adding

00:17:20 studying different systems

00:17:23 this is water, for example

00:17:26 has a different slope

00:17:28 now the slopes are very informative, aren't they

00:17:31 yes, they are

00:17:32 they tell the entropy of solution

00:17:34 yes, and the fact that they're straight lines

00:17:37 makes it possible to

00:17:39 pick out the

00:17:41 exact value

00:17:43 now here

00:17:45 here is

00:17:47 that's ethanol

00:17:48 ethanol

00:17:49 that's the one we just demonstrated

00:17:51 yes

00:17:52 and it has a different slope

00:17:53 here's benzene

00:17:55 that's why it is red instead of

00:17:59 and then here is

00:18:01 that's some acetylene

00:18:03 all these

00:18:04 now let me

00:18:06 these are straight here

00:18:08 until we get them

00:18:11 that might be good to do that again

00:18:15 if you would

00:18:16 see, we start with water down here

00:18:18 you pointed to that

00:18:19 then ethanol here

00:18:21 and there's benzene

00:18:23 and there's acetylene

00:18:25 and then after that

00:18:26 we're going to go up here

00:18:27 and talk about the s-shaped part

00:18:29 studying different systems

00:18:33 this is water, for example

00:18:37 has a different slope

00:18:39 now the slopes are very

00:18:49 you want to show the

00:18:51 it doesn't matter

00:18:52 it must be your left hand

00:18:54 I can see it

00:18:55 it's better if it's back where it is

00:18:57 because we don't want it prominent

00:19:00 the only problem

00:19:01 is that you sometimes hold the paper

00:19:03 with one hand and sometimes with the other

00:19:05 and we just have to match that

00:19:07 you're still rolling?

00:19:09 water, for example

00:19:14 I kept adding this

00:19:16 studying different systems

00:19:17 he's going to start over again now

00:19:18 here we go

00:19:19 this is water, for example

00:19:22 has a different slope

00:19:24 now the slopes are very informative, aren't they?

00:19:27 yes, they are

00:19:28 they tell the entropy of solution

00:19:30 yes, and the fact that they're straight lines

00:19:33 makes it possible to

00:19:35 pick out the exact value

00:19:39 now here

00:19:41 here is

00:19:43 that's ethanol

00:19:45 that's the one we just demonstrated

00:19:47 and it has a different slope

00:19:49 here's benzene

00:19:51 that's why it is red instead of

00:19:55 and then here is

00:19:57 that's mesitylene

00:19:59 all these

00:20:00 now when we

00:20:02 these are straight here

00:20:04 until we get up near

00:20:06 the melting point

00:20:11 we ought to make

00:20:13 we ought to make it plain that the

00:20:16 that it's the

00:20:18 valid solution that are straight

00:20:20 there may be a

00:20:23 change with temperature, for instance

00:20:26 in either

00:20:28 see, when they say

00:20:30 up to the melting point

00:20:31 you want to bring your finger up there

00:20:34 like that

00:20:37 you say

00:20:38 in the track you say it's straight

00:20:40 until you get up to the melting point

00:20:43 near the melting point

00:20:44 well, near the melting point

00:20:45 but anyway, to get your finger up there

00:20:50 we want to have your

00:20:52 hand holding the paper

00:20:53 pretty much the way it is on the screen

00:20:56 let's move it out this way a little bit

00:20:58 that's good

00:21:01 now we're going to start

00:21:03 again

00:21:05 shift over

00:21:07 there is

00:21:09 that's ethanol

00:21:10 ethanol

00:21:11 that's the one we just demonstrated

00:21:13 yes

00:21:14 and it has a different slope

00:21:15 here's benzene

00:21:17 that's why it is red instead of

00:21:21 and then here is

00:21:23 that's mesitylene

00:21:25 all these

00:21:26 now when we

00:21:28 these are

00:21:34 when you go up here

00:21:35 you change, that's it

00:21:36 with your right hand now

00:21:37 you follow it all the way up

00:21:39 straight here

00:21:41 until we get up near

00:21:43 the

00:21:45 melting point

00:21:47 and this has a

00:21:49 S shape

00:21:51 and that is

00:21:53 like the S shape of

00:21:55 of

00:21:57 a

00:22:09 a binary solution

00:22:11 I can recognize

00:22:13 this

00:22:21 could you hold the paper

00:22:23 with this hand

00:22:25 binary solution

00:22:27 I can recognize

00:22:29 that this

00:22:31 S shape

00:22:33 meant a liquid

00:22:35 curve

00:22:37 yes

00:22:39 this is one of my favorite

00:22:41 results because

00:22:43 it was absolutely opaque

00:22:45 so much

00:22:47 ID

00:22:49 but I had

00:22:51 in order to fix

00:22:53 this

00:22:55 this curve

00:22:57 I had to

00:23:09 you are now able to see

00:23:11 now then

00:23:13 the systems which are

00:23:15 are regular

00:23:17 violet, all violet

00:23:19 belong to a

00:23:21 another

00:23:25 to another

00:23:27 theory than

00:23:29 these others

00:23:31 well now then

00:23:33 all of these slopes

00:23:35 are points

00:23:37 the points fall on this line

00:23:45 these slopes

00:23:47 are points

00:23:49 fall on this line

00:23:51 and this is the problem of entropy

00:23:53 so these would be the violet solution

00:23:55 yes

00:23:57 these are all brown

00:23:59 or some other color

00:24:01 now that's very

00:24:03 very important to be able to

00:24:05 ok did we get that ok

00:24:09 ok

00:24:13 and then after the 45

00:24:15 degree line

00:24:17 these are the two

00:24:19 members

00:24:21 of the equation

00:24:23 for regular

00:24:25 solutions

00:24:27 and all of these points fall on

00:24:29 the 45 degree line

00:24:31 you see

00:24:33 solubility parameters

00:24:35 solubility parameters

00:24:37 yes

00:24:39 and these are the solubility

00:24:43 now these are not on the line

00:24:45 because they shouldn't be

00:24:47 the polar

00:24:51 and they have different attractions

00:24:53 for each other but not

00:24:55 for instance like acetone

00:24:57 would that be an example

00:24:59 yes

00:25:01 these are

00:25:05 the aromatics

00:25:07 aromatics

00:25:09 from toluene

00:25:11 to azimuthalene

00:25:13 these are

00:25:15 fluorocarbons

00:25:17 but these are

00:25:19 a long time puzzle

00:25:23 these are

00:25:25 this is carbon

00:25:27 this is cyclohexane

00:25:29 this is

00:25:31 monomethylcyclohexane

00:25:33 this is dimethyl

00:25:37 these are

00:25:41 straight chain paraffins

00:25:43 that are falling off the curve

00:25:45 they are falling off this curve

00:25:49 but they

00:25:51 diverge

00:25:53 more

00:25:55 as you get to the

00:25:57 shorter

00:26:03 line

00:26:05 these are all linear

00:26:07 these are

00:26:09 these like

00:26:11 iso-octane

00:26:13 have more than

00:26:15 more than

00:26:17 the two methyl groups

00:26:19 on the end

00:26:21 more methyl groups

00:26:23 iso-octane

00:26:25 has

00:26:27 five methyl groups

00:26:31 this point is octamethyl

00:26:33 tetracyloxane

00:26:37 the more

00:26:39 methyl groups

00:26:41 you have a

00:26:43 you have a copy

00:26:45 that shows that

00:26:47 they left

00:26:49 the methyl groups

00:26:51 out

00:26:53 and they

00:26:55 fall on a

00:26:57 straight line

00:27:01 this is the farthest away

00:27:03 and then

00:27:05 these next and these

00:27:07 next

00:27:09 all of this represented

00:27:11 I think

00:27:13 one of the earliest

00:27:15 recognitions of importance

00:27:19 Joel's telling me that

00:27:21 that he wants to point at

00:27:23 is octamethyl

00:27:25 or octamethyl tetracyloxane

00:27:29 I don't think we can change the

00:27:31 paper, but you're pointing where it belongs

00:27:33 yeah, I think

00:27:35 you're still rolling

00:27:37 let's do that for the second

00:27:39 the only copy we have

00:27:41 I can

00:27:43 put it on the

00:27:45 it wouldn't quite match

00:27:47 alright

00:27:49 yeah

00:27:51 five methyl groups

00:27:53 this point

00:27:55 is octamethyl

00:27:57 tetracyloxane

00:27:59 eight methyl groups

00:28:01 the more methyl groups

00:28:05 the more

00:28:07 they diverge

00:28:11 but now the number of

00:28:13 the methyl groups

00:28:16 falls on a

00:28:18 on a straight line

00:28:21 is that this straight line?

00:28:23 no

00:28:25 it ought to be a line

00:28:27 like that

00:28:29 on a line like that

00:28:31 all of this

00:28:33 represented

00:28:39 by use of entropy

00:28:41 brought it to

00:28:43 its correct form

00:28:45 this is

00:28:47 a plot

00:28:49 of non-polar

00:28:51 liquids

00:28:53 and there are

00:28:55 a number of non-polar liquids

00:28:57 and the

00:28:59 polarity

00:29:01 would make them steeper

00:29:05 therefore

00:29:07 here is a line

00:29:09 of

00:29:13 see you're holding the paper

00:29:15 in the middle with this hand

00:29:17 yeah

00:29:19 how many points at this slope

00:29:23 therefore

00:29:25 here is a line

00:29:27 of certain volume

00:29:29 it's a hundred liters

00:29:31 vapor

00:29:33 vapor volume

00:29:35 pretty well dilute gas

00:29:37 so you can apply the gas law

00:29:39 to it

00:29:41 it could be almost anything as long as it's pretty dilute

00:29:43 yes

00:29:45 and you're consistent

00:29:47 now the slope

00:29:49 at such a line

00:29:51 at the intersection

00:29:53 yes

00:29:55 is the entropy

00:30:03 now that

00:30:05 very important

00:30:07 is that this

00:30:09 that there

00:30:11 exists

00:30:13 a number of liquids

00:30:15 which have the same

00:30:17 entropy at the same

00:30:19 vapor volume

00:30:23 up and down

00:30:25 that's it

00:30:27 and

00:30:29 that's it

00:30:31 that's it

00:30:33 and that means

00:30:35 that they

00:30:37 have the maximum

00:30:39 disorder

00:30:41 yes

00:30:53 by your figure here

00:30:55 yes

00:30:57 molar volume behavior is a function

00:30:59 of temperature

00:31:03 Harry this is

00:31:05 let's see this is

00:31:07 ferroxylene and metaxylene

00:31:09 yes

00:31:11 showing how the molar volume changes with temperature

00:31:13 and absolutely

00:31:21 you know what

00:31:25 I don't have the same coat

00:31:27 I wore my suit coat

00:31:29 thinking I had my suit on

00:31:32 you think that

00:31:36 does my watch show

00:31:38 ferroxylene and metaxylene

00:31:40 showing how the molar volume changes

00:31:42 with temperature

00:31:47 well I've got

00:31:49 I think my sleeve

00:31:51 doesn't show

00:31:53 my shirt sleeve does but not mine

00:31:55 the point is

00:31:57 make here that

00:32:01 the ferroxylene

00:32:07 and the metaxylene

00:32:09 solid

00:32:11 have very different volumes

00:32:13 and yet

00:32:15 there's no evidence

00:32:17 that in this liquid state

00:32:19 they differ

00:32:21 I reach in with my left hand

00:32:23 and point at these curves

00:32:25 like that

00:32:27 oh that's good

00:32:29 that's good

00:32:39 like this

00:32:49 so this time I do the point

00:32:59 and I'm reading it

00:33:01 so I think I can follow

00:33:07 let me hear it

00:33:09 so

00:33:11 ferroxylene and metaxylene

00:33:13 showing

00:33:15 showing how the

00:33:17 ok

00:33:23 ferroxylene and metaxylene

00:33:25 yes

00:33:27 showing how the molar volume

00:33:29 changes with temperature

00:33:31 and absolutely

00:33:33 no manifold

00:33:47 I'm in the way

00:33:49 I think you're ok

00:33:51 is that alright now

00:33:53 you ok

00:33:57 I ring

00:33:59 ferroxylene and metaxylene

00:34:01 showing how the molar volume

00:34:03 changes with temperature

00:34:05 and absolutely

00:34:07 no manifestation of the

00:34:09 impending molar volume

00:34:11 change immediately before

00:34:13 the crystallization

00:34:15 point and as you point out

00:34:17 this

00:34:19 obviously indicates that there's

00:34:21 no preliminary

00:34:23 freezing

00:34:31 I checked

00:34:33 it looked ok

00:34:35 I checked

00:34:37 you may not feel it

00:34:39 sufficiently

00:34:41 that's the only one

00:34:43 but I think they're all ok

00:34:47 I think that's all

00:34:51 oh yeah

00:34:53 yeah

00:34:55 that's it

00:34:57 now we got the metals

00:34:59 I think it will be alright

00:35:01 if you hold it right up against your body

00:35:03 alright

00:35:05 ok we want to get tight in just on this metal

00:35:07 you got it

00:35:09 ok and with your finger point to it

00:35:11 yes

00:35:15 tight in on that

00:35:17 ok

00:35:19 I was in

00:35:21 real trouble

00:35:25 now point across

00:35:27 to the other metal here

00:35:29 this one

00:35:31 a little farther down

00:35:33 so you get a cleaner picture

00:35:35 there that's good

00:35:37 we're doing one at a time

00:35:39 so you don't have to see it

00:35:41 not quite a match

00:35:43 that's ok

00:35:49 ok

00:35:55 point on this side

00:35:57 that's it

00:35:59 the nickel's metal

00:36:01 is the angle alright

00:36:03 or should it be

00:36:05 hold on

00:36:07 nickel's metal is

00:36:09 the other side of it

00:36:11 is that right

00:36:13 is that the right side

00:36:15 you getting that

00:36:17 this is the back

00:36:19 that's the front

00:36:21 now do you want the Gibbs

00:36:23 you want the other picture

00:36:25 this is the Gibbs metal

00:36:27 no I don't have the other picture

00:36:29 oh

00:36:31 this is the Priestly metal

00:36:33 well

00:36:35 yeah

00:36:37 I think that it will only be this one

00:36:39 and it's so large

00:36:41 I think the shot will be ok

00:36:43 you got the other two

00:36:45 ok stop tape

00:36:51 no

00:36:53 you're not

00:36:55 doing it for the other metals

00:36:57 ok

00:37:11 I think we probably have that

00:37:13 I don't see the other thing

00:37:23 I think that's it

00:37:27 stop tape

00:37:33 watch his left hand

00:37:37 so we need to hold it with the left hand

00:37:41 ok you have speed

00:37:43 we have speed

00:37:45 ok I want to

00:37:49 tell me when to turn it over

00:37:51 I just want to hold that for a little bit

00:37:57 it's a nice picture isn't it

00:37:59 yes

00:38:27 ok

00:38:29 all done

00:38:37 but all of this represented I think

00:38:39 one of the earliest recognitions

00:38:41 of the importance of entropy

00:38:43 and understanding solution

00:38:45 behavior

00:38:47 let me read a sentence you wrote in your Priestly

00:38:49 lecture in 1965

00:38:51 and of course

00:38:53 you were stating in 1965

00:38:55 something you'd recognize back

00:38:57 I think in the early 20's

00:38:59 entropy

00:39:01 is the thermodynamic function

00:39:03 most closely related to structure

00:39:05 and maximum entropy

00:39:07 of mixing indicates that the molecules

00:39:09 of the mixture are in a

00:39:11 state of maximum disorder

00:39:13 that gave you

00:39:15 a norm to make these comparisons

00:39:17 and of course in addition

00:39:19 gave you the opportunity

00:39:21 to

00:39:23 that's where I

00:39:25 interrupted