[Script Info]
Title: 
[Events]
Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
Dialogue: 0,9:59:59.99,9:59:59.99,Default,,0000,0000,0000,,
Dialogue: 0,0:00:00.45,0:00:02.55,Default,,0000,0000,0000,,In this video, I want to\Ncover several topics
Dialogue: 0,0:00:02.55,0:00:03.65,Default,,0000,0000,0000,,that are all related.
Dialogue: 0,0:00:03.65,0:00:05.85,Default,,0000,0000,0000,,And on some level, they're\Nreally simple, but on a whole
Dialogue: 0,0:00:05.85,0:00:07.88,Default,,0000,0000,0000,,other level, they tend to\Nconfuse people a lot.
Dialogue: 0,0:00:07.88,0:00:10.11,Default,,0000,0000,0000,,So hopefully we can\Nmake some headway.
Dialogue: 0,0:00:10.11,0:00:12.40,Default,,0000,0000,0000,,So a good place to start-- let's\Njust imagine that I have
Dialogue: 0,0:00:12.40,0:00:15.46,Default,,0000,0000,0000,,some type of container here.
Dialogue: 0,0:00:15.46,0:00:18.13,Default,,0000,0000,0000,,Let's say that's my container\Nand inside of that container,
Dialogue: 0,0:00:18.13,0:00:21.43,Default,,0000,0000,0000,,I have a bunch of\Nwater molecules.
Dialogue: 0,0:00:21.43,0:00:24.07,Default,,0000,0000,0000,,It's just got a bunch\Nof water molecules.
Dialogue: 0,0:00:24.07,0:00:25.55,Default,,0000,0000,0000,,They're all rubbing against\Neach other.
Dialogue: 0,0:00:25.55,0:00:27.92,Default,,0000,0000,0000,,It's in its liquid form,\Nthis is liquid water.
Dialogue: 0,0:00:27.92,0:00:30.34,Default,,0000,0000,0000,,and inside of the water\Nmolecules, I
Dialogue: 0,0:00:30.34,0:00:33.05,Default,,0000,0000,0000,,have some sugar molecules.
Dialogue: 0,0:00:33.05,0:00:35.79,Default,,0000,0000,0000,,Maybe I'll do sugar in\Nthis pink color.
Dialogue: 0,0:00:35.79,0:00:40.69,Default,,0000,0000,0000,,So I have a bunch of sugar\Nmolecules right here.
Dialogue: 0,0:00:40.69,0:00:43.04,Default,,0000,0000,0000,,I have many, many more water\Nmolecules though.
Dialogue: 0,0:00:43.04,0:00:44.29,Default,,0000,0000,0000,,I want to make that clear.
Dialogue: 0,0:00:44.29,0:00:49.42,Default,,0000,0000,0000,,I have many, many more water molecules in this container that we are dealing with.
Dialogue: 0,0:00:49.42,0:00:55.66,Default,,0000,0000,0000,,Now in this type of situation,\Nwe call, we call the thing that there's
Dialogue: 0,0:00:55.66,0:01:00.44,Default,,0000,0000,0000,,more of, the solvent.
Dialogue: 0,0:01:00.44,0:01:03.35,Default,,0000,0000,0000,,So in this case, there's more\Nwater molecules and you can
Dialogue: 0,0:01:03.35,0:01:07.99,Default,,0000,0000,0000,,literally just view more as\Nthe number of molecules.
Dialogue: 0,0:01:07.99,0:01:10.01,Default,,0000,0000,0000,,I'm not going to go into a whole\Ndiscussion of moles and
Dialogue: 0,0:01:10.01,0:01:13.14,Default,,0000,0000,0000,,all of that because you may or\Nmay not have been exposed to
Dialogue: 0,0:01:13.14,0:01:15.67,Default,,0000,0000,0000,,that yet, but just imagine\Nwhatever there's more of,
Dialogue: 0,0:01:15.67,0:01:17.74,Default,,0000,0000,0000,,that's what we're going\Nto call the solvent.
Dialogue: 0,0:01:17.74,0:01:24.63,Default,,0000,0000,0000,,So in this case, water\Nis the solvent.
Dialogue: 0,0:01:24.63,0:01:30.03,Default,,0000,0000,0000,,And whatever there is less of, so the more water is the solvent and in that case, that is the\Nin this case, that is the
Dialogue: 0,0:01:30.03,0:01:32.73,Default,,0000,0000,0000,,sugar-- that is considered\Nthe solute.
Dialogue: 0,0:01:32.73,0:01:36.29,Default,,0000,0000,0000,,this is the solute, so the sugar.
Dialogue: 0,0:01:36.29,0:01:37.64,Default,,0000,0000,0000,,It doesn't have to be sugar.
Dialogue: 0,0:01:37.64,0:01:40.32,Default,,0000,0000,0000,,It could be any molecule that\Nthere's less of, in the water,
Dialogue: 0,0:01:40.32,0:01:41.57,Default,,0000,0000,0000,,in this case,sugar.
Dialogue: 0,0:01:41.57,0:01:45.75,Default,,0000,0000,0000,,is the solute
Dialogue: 0,0:01:45.75,0:01:49.62,Default,,0000,0000,0000,,And we say that the sugar has\Nbeen dissolved into the water.
Dialogue: 0,0:01:49.62,0:02:03.50,Default,,0000,0000,0000,,sugar,has been dissolved, dissolved into, into the water
Dialogue: 0,0:02:03.50,0:02:06.42,Default,,0000,0000,0000,,And this whole thing right here,\Nthe combination of the
Dialogue: 0,0:02:06.42,0:02:10.23,Default,,0000,0000,0000,,water and the sugar molecules,\Nwe call a solution.
Dialogue: 0,0:02:10.23,0:02:14.14,Default,,0000,0000,0000,,We call this whole\Nthing a solution.
Dialogue: 0,0:02:14.14,0:02:16.87,Default,,0000,0000,0000,,And a solution has a solvent\Nand the solute.
Dialogue: 0,0:02:16.87,0:02:18.16,Default,,0000,0000,0000,,The solvent is water.
Dialogue: 0,0:02:18.16,0:02:21.11,Default,,0000,0000,0000,,That's the thing doing the\Ndissolving and the thing that
Dialogue: 0,0:02:21.11,0:02:23.22,Default,,0000,0000,0000,,is dissolved is the sugar.
Dialogue: 0,0:02:23.22,0:02:24.29,Default,,0000,0000,0000,,That's the solute.
Dialogue: 0,0:02:24.29,0:02:27.95,Default,,0000,0000,0000,,Now all of this may or may not\Nbe review for you, but I'm
Dialogue: 0,0:02:27.95,0:02:32.87,Default,,0000,0000,0000,,doing it for a reason-- because\NI want to talk about, I want to talk about
Dialogue: 0,0:02:32.87,0:02:34.37,Default,,0000,0000,0000,,the idea of diffusion, diffusion
Dialogue: 0,0:02:39.96,0:02:43.49,Default,,0000,0000,0000,,And the,the idea is actually\Npretty straightforward.
Dialogue: 0,0:02:43.49,0:02:46.79,Default,,0000,0000,0000,,If I have, let's say,let's same\Nthe same container.
Dialogue: 0,0:02:46.79,0:02:49.60,Default,,0000,0000,0000,,Let me do it in a slightly\Ndifferent container here, just
Dialogue: 0,0:02:49.60,0:02:50.64,Default,,0000,0000,0000,,to talk about diffusion.
Dialogue: 0,0:02:50.64,0:02:52.18,Default,,0000,0000,0000,,We'll go back to water\Nand sugar--
Dialogue: 0,0:02:52.18,0:02:54.07,Default,,0000,0000,0000,,especially back to water.
Dialogue: 0,0:02:54.07,0:02:58.57,Default,,0000,0000,0000,,Let's say we have a container\Nhere and let's say it just has
Dialogue: 0,0:02:58.57,0:03:00.83,Default,,0000,0000,0000,,a bunch of-- let's say it just\Nhas some air particles in it.
Dialogue: 0,0:03:00.83,0:03:03.56,Default,,0000,0000,0000,,It could be anything-- oxygen\Nor carbon dioxide.
Dialogue: 0,0:03:03.56,0:03:07.88,Default,,0000,0000,0000,,So let me just draw a couple\Nof air molecules here.
Dialogue: 0,0:03:07.88,0:03:11.06,Default,,0000,0000,0000,,So let's say that that is a\Ngaseous-- just for the sake of
Dialogue: 0,0:03:11.06,0:03:12.59,Default,,0000,0000,0000,,argument-- gaseous oxygen.
Dialogue: 0,0:03:12.59,0:03:14.90,Default,,0000,0000,0000,,So each of this is an O2--\Neach of those, right?
Dialogue: 0,0:03:14.90,0:03:16.90,Default,,0000,0000,0000,,And let's say that this is the\Ncurrent configuration, that
Dialogue: 0,0:03:16.90,0:03:19.71,Default,,0000,0000,0000,,all of this is a vacuum here\Nand that there's some
Dialogue: 0,0:03:19.71,0:03:20.22,Default,,0000,0000,0000,,temperatures.
Dialogue: 0,0:03:20.22,0:03:22.49,Default,,0000,0000,0000,,So these water molecules,\Nthey have some
Dialogue: 0,0:03:22.49,0:03:25.28,Default,,0000,0000,0000,,type, some type of kinetic energy.
Dialogue: 0,0:03:25.28,0:03:29.62,Default,,0000,0000,0000,,They're moving in some type of\Nrandom directions right there.
Dialogue: 0,0:03:29.62,0:03:34.76,Default,,0000,0000,0000,,So my question is, what is going\Nto happen, what is goign to happen in this type
Dialogue: 0,0:03:34.76,0:03:35.81,Default,,0000,0000,0000,,of container?
Dialogue: 0,0:03:35.81,0:03:38.71,Default,,0000,0000,0000,,Well, any of these guys are\Ngoing to be randomly bumping
Dialogue: 0,0:03:38.71,0:03:39.77,Default,,0000,0000,0000,,into each other.
Dialogue: 0,0:03:39.77,0:03:43.03,Default,,0000,0000,0000,,They're more likely to bump into\Nthings in this down-left
Dialogue: 0,0:03:43.03,0:03:45.12,Default,,0000,0000,0000,,direction than they are in\Nthe up-right direction.
Dialogue: 0,0:03:45.12,0:03:47.97,Default,,0000,0000,0000,,So if this guy was happening\Nto go in this down-left
Dialogue: 0,0:03:47.97,0:03:50.11,Default,,0000,0000,0000,,direction, he's going to bump\Ninto something and then
Dialogue: 0,0:03:50.11,0:03:52.07,Default,,0000,0000,0000,,ricochet into the up-right\Ndirection.
Dialogue: 0,0:03:52.07,0:03:53.48,Default,,0000,0000,0000,,But in the up-right\Ndirection, there's
Dialogue: 0,0:03:53.48,0:03:55.04,Default,,0000,0000,0000,,nothing to bounce into.
Dialogue: 0,0:03:55.04,0:03:57.99,Default,,0000,0000,0000,,So in general, everything is\Nmoving in random directions,
Dialogue: 0,0:03:57.99,0:04:00.25,Default,,0000,0000,0000,,but you're more likely\Nto be able to move in
Dialogue: 0,0:04:00.25,0:04:01.00,Default,,0000,0000,0000,,the rightward direction.
Dialogue: 0,0:04:01.00,0:04:02.50,Default,,0000,0000,0000,,When you go to the left, you're\Nmore likely to bump
Dialogue: 0,0:04:02.50,0:04:04.13,Default,,0000,0000,0000,,into each other, into something.
Dialogue: 0,0:04:04.13,0:04:06.09,Default,,0000,0000,0000,,So it's almost common sense.
Dialogue: 0,0:04:06.09,0:04:09.55,Default,,0000,0000,0000,,Over time, if you just let this\Nsystem come to some type
Dialogue: 0,0:04:09.55,0:04:11.58,Default,,0000,0000,0000,,of equilibrium-- I'm not\Ngoing to go into detail
Dialogue: 0,0:04:11.58,0:04:12.34,Default,,0000,0000,0000,,on what that means.
Dialogue: 0,0:04:12.34,0:04:14.34,Default,,0000,0000,0000,,You can watch the thermodynamics\Nvideos if you'd
Dialogue: 0,0:04:14.34,0:04:15.47,Default,,0000,0000,0000,,like to see that.
Dialogue: 0,0:04:15.47,0:04:18.00,Default,,0000,0000,0000,,You'll eventually see the\Ncontainer will look
Dialogue: 0,0:04:18.00,0:04:19.14,Default,,0000,0000,0000,,something like this.
Dialogue: 0,0:04:19.14,0:04:20.20,Default,,0000,0000,0000,,I can't guarantee it.
Dialogue: 0,0:04:20.20,0:04:22.50,Default,,0000,0000,0000,,There's some probability it\Nwould actually stay like this,
Dialogue: 0,0:04:22.50,0:04:25.92,Default,,0000,0000,0000,,but very likely that those five\Nparticles are going to
Dialogue: 0,0:04:25.92,0:04:27.97,Default,,0000,0000,0000,,get relatively spread out.
Dialogue: 0,0:04:27.97,0:04:32.79,Default,,0000,0000,0000,,This is diffusion and so it's\Nreally just the spreading of
Dialogue: 0,0:04:32.79,0:04:36.94,Default,,0000,0000,0000,,particles or molecules from\Nhigh concentration to low
Dialogue: 0,0:04:36.94,0:04:39.14,Default,,0000,0000,0000,,concentration areas, right?
Dialogue: 0,0:04:39.14,0:04:41.42,Default,,0000,0000,0000,,In this case, the molecules are\Ngoing to spread in that
Dialogue: 0,0:04:41.42,0:04:43.78,Default,,0000,0000,0000,,direction from a high\Nconcentration to a low
Dialogue: 0,0:04:43.78,0:04:45.13,Default,,0000,0000,0000,,concentration area.
Dialogue: 0,0:04:45.13,0:04:47.92,Default,,0000,0000,0000,,Now you're saying, Sal,\Nwhat is concentration?
Dialogue: 0,0:04:47.92,0:04:51.06,Default,,0000,0000,0000,,And there's many ways to measure\Nconcentration and you
Dialogue: 0,0:04:51.06,0:04:54.12,Default,,0000,0000,0000,,can go into molarity and\Nmolality and all of that.
Dialogue: 0,0:04:54.12,0:04:57.83,Default,,0000,0000,0000,,But the very simple idea is, how\Nmuch of that particle do
Dialogue: 0,0:04:57.83,0:04:59.90,Default,,0000,0000,0000,,you have per unit space?
Dialogue: 0,0:04:59.90,0:05:02.78,Default,,0000,0000,0000,,So here, you have a lot of those\Nparticles per unit space
Dialogue: 0,0:05:02.78,0:05:04.55,Default,,0000,0000,0000,,and here you have very\Nfew of those
Dialogue: 0,0:05:04.55,0:05:05.85,Default,,0000,0000,0000,,particles per unit space.
Dialogue: 0,0:05:05.85,0:05:09.23,Default,,0000,0000,0000,,So this is a high concentration\Nand that's a low
Dialogue: 0,0:05:09.23,0:05:09.97,Default,,0000,0000,0000,,concentration.
Dialogue: 0,0:05:09.97,0:05:12.74,Default,,0000,0000,0000,,So you could imagine other\Nexperiments like this.
Dialogue: 0,0:05:12.74,0:05:17.00,Default,,0000,0000,0000,,You could imagine a solution\Nlike-- let's do
Dialogue: 0,0:05:17.00,0:05:18.25,Default,,0000,0000,0000,,something like this.
Dialogue: 0,0:05:18.25,0:05:21.57,Default,,0000,0000,0000,,let me make
Dialogue: 0,0:05:21.57,0:05:22.82,Default,,0000,0000,0000,,Let's say I have\Ntwo containers.
Dialogue: 0,0:05:22.82,0:05:25.44,Default,,0000,0000,0000,,let's see two container.
Dialogue: 0,0:05:25.44,0:05:27.23,Default,,0000,0000,0000,,Let's go back to the\Nsolution situation.
Dialogue: 0,0:05:27.23,0:05:29.72,Default,,0000,0000,0000,,This was a gas, but I started\Noff with that example so let's
Dialogue: 0,0:05:29.72,0:05:31.43,Default,,0000,0000,0000,,stay with that example.
Dialogue: 0,0:05:31.43,0:05:35.53,Default,,0000,0000,0000,,So let's say that I have a door\Nright there that's larger
Dialogue: 0,0:05:35.53,0:05:38.37,Default,,0000,0000,0000,,than either the water or\Nthe sugar molecules.
Dialogue: 0,0:05:38.37,0:05:41.30,Default,,0000,0000,0000,,On either side, I have a bunch\Nof water molecules.
Dialogue: 0,0:05:41.30,0:05:52.02,Default,,0000,0000,0000,,I have a bunch of water molecules on either side, just like that on either side
Dialogue: 0,0:05:52.02,0:05:53.30,Default,,0000,0000,0000,,So I have a lot of\Nwater molecules.
Dialogue: 0,0:05:53.30,0:05:55.65,Default,,0000,0000,0000,,So if I just had water molecules\Nhere-- they're all
Dialogue: 0,0:05:55.65,0:05:58.69,Default,,0000,0000,0000,,bouncing around in random\Ndirections-- and so the odds
Dialogue: 0,0:05:58.69,0:06:01.89,Default,,0000,0000,0000,,of a water molecule going this\Nway, equivalent to what odds of a
Dialogue: 0,0:06:01.89,0:06:04.59,Default,,0000,0000,0000,,water molecule going that way,\Nassuming that both sides have
Dialogue: 0,0:06:04.59,0:06:06.57,Default,,0000,0000,0000,,the same level of water\Nmolecule, otherwise the
Dialogue: 0,0:06:06.57,0:06:07.51,Default,,0000,0000,0000,,pressures would be different.
Dialogue: 0,0:06:07.51,0:06:10.07,Default,,0000,0000,0000,,But let's say, you know that the top\Nof this is the same
Dialogue: 0,0:06:10.07,0:06:11.17,Default,,0000,0000,0000,,as the top of this.
Dialogue: 0,0:06:11.17,0:06:12.73,Default,,0000,0000,0000,,So there's no more pressure\Ngoing in one
Dialogue: 0,0:06:12.73,0:06:13.79,Default,,0000,0000,0000,,direction or another.
Dialogue: 0,0:06:13.79,0:06:17.24,Default,,0000,0000,0000,,So you know if,it for whatever reason, a\Nbunch of more water molecules
Dialogue: 0,0:06:17.24,0:06:18.77,Default,,0000,0000,0000,,were going in the rightward\Ndirection, then all of a
Dialogue: 0,0:06:18.77,0:06:20.76,Default,,0000,0000,0000,,sudden this would fill up with\Nmore water and we know that
Dialogue: 0,0:06:20.76,0:06:22.62,Default,,0000,0000,0000,,that isn't likely to occur.
Dialogue: 0,0:06:22.62,0:06:28.20,Default,,0000,0000,0000,,So this is,you know, this is just a solution, with or , this is just two containers of waters\Nof water.
Dialogue: 0,0:06:28.20,0:06:30.34,Default,,0000,0000,0000,,Now let's put some\Nsolute in it.
Dialogue: 0,0:06:30.34,0:06:33.23,Default,,0000,0000,0000,,Let's dissolve some solute in it\Nand let's say we do all the
Dialogue: 0,0:06:33.23,0:06:35.63,Default,,0000,0000,0000,,dissolving on the\Nleft-hand side.
Dialogue: 0,0:06:35.63,0:06:40.62,Default,,0000,0000,0000,,So we put some sugar molecules\Non the left-hand side.
Dialogue: 0,0:06:40.62,0:06:42.91,Default,,0000,0000,0000,,And these are small enough to\Nfit through this little pipe.
Dialogue: 0,0:06:42.91,0:06:44.28,Default,,0000,0000,0000,,right, that's just one assumption\Nthat I'm making.
Dialogue: 0,0:06:44.28,0:06:45.12,Default,,0000,0000,0000,,So what's going to happen?
Dialogue: 0,0:06:45.12,0:06:47.71,Default,,0000,0000,0000,,All of these things have some\Ntype of kinetic energy.
Dialogue: 0,0:06:47.71,0:06:52.63,Default,,0000,0000,0000,,They're all bouncing , they're all bouncing around.
Dialogue: 0,0:06:52.63,0:06:56.25,Default,,0000,0000,0000,,Well, over time,you know, the water's\Ngoing back and forth.
Dialogue: 0,0:06:56.25,0:06:57.60,Default,,0000,0000,0000,,This water molecule\Nmight go that way.
Dialogue: 0,0:06:57.60,0:07:00.04,Default,,0000,0000,0000,,That water molecule might go\Nthat way, but they net out each
Dialogue: 0,0:07:00.04,0:07:03.81,Default,,0000,0000,0000,,other out, but over time one of\Nthese big sugar molecules
Dialogue: 0,0:07:03.81,0:07:06.52,Default,,0000,0000,0000,,will be going in just the\Nright direction to go
Dialogue: 0,0:07:06.52,0:07:08.47,Default,,0000,0000,0000,,through--maybe you know maybe this guy's,\Ninstead of going that
Dialogue: 0,0:07:08.47,0:07:10.38,Default,,0000,0000,0000,,direction, he starts off going\Nin that direction.
Dialogue: 0,0:07:10.38,0:07:15.63,Default,,0000,0000,0000,,He goes just through this,throught this,uhm throught this tunnel\Nconnecting this two
Dialogue: 0,0:07:15.63,0:07:18.05,Default,,0000,0000,0000,,containers and he'll end\Nup there, right?
Dialogue: 0,0:07:18.05,0:07:20.32,Default,,0000,0000,0000,,And this guy will still\Nbe bouncing around.
Dialogue: 0,0:07:20.32,0:07:23.57,Default,,0000,0000,0000,,There's some probability he goes\Nback, but there's still
Dialogue: 0,0:07:23.57,0:07:25.42,Default,,0000,0000,0000,,more particles,more sugar particles\Nhere than there.
Dialogue: 0,0:07:25.42,0:07:31.35,Default,,0000,0000,0000,,So there's still more\Nprobability that one of, so these
Dialogue: 0,0:07:31.35,0:07:33.35,Default,,0000,0000,0000,,guys will go to that side\Nthan one of these guys
Dialogue: 0,0:07:33.35,0:07:34.34,Default,,0000,0000,0000,,will go to that side, that one of these guys will go to that side,
Dialogue: 0,0:07:34.34,0:07:36.98,Default,,0000,0000,0000,,So you can imagine if you're\Ndoing this with gazillions of
Dialogue: 0,0:07:36.98,0:07:40.65,Default,,0000,0000,0000,,particles-- I'm only doing it\Nwith four-- over time, the
Dialogue: 0,0:07:40.65,0:07:43.44,Default,,0000,0000,0000,,particles will have spread out\Nso that their concentrations
Dialogue: 0,0:07:43.44,0:07:44.55,Default,,0000,0000,0000,,are roughly equal.
Dialogue: 0,0:07:44.55,0:07:46.95,Default,,0000,0000,0000,,So that maybe you'll have\Ntwo here over time.
Dialogue: 0,0:07:46.95,0:07:49.43,Default,,0000,0000,0000,,But if, but when you're only dealing\Nwith three or four or five
Dialogue: 0,0:07:49.43,0:07:51.38,Default,,0000,0000,0000,,particles, there's some\Nprobability it doesn't happen,
Dialogue: 0,0:07:51.38,0:07:53.24,Default,,0000,0000,0000,,but when you're doing it with a\Ngazillion and they're super
Dialogue: 0,0:07:53.24,0:07:56.81,Default,,0000,0000,0000,,small, it's a very, very,\Nvery high likelihood.
Dialogue: 0,0:07:56.81,0:07:59.59,Default,,0000,0000,0000,,But anyway, this whole process--\Nwe went from a
Dialogue: 0,0:07:59.59,0:08:02.46,Default,,0000,0000,0000,,container of high concentration\Nto a container
Dialogue: 0,0:08:02.46,0:08:06.08,Default,,0000,0000,0000,,of low concentration and the\Nparticles would have spread
Dialogue: 0,0:08:06.08,0:08:08.53,Default,,0000,0000,0000,,from the low concentration\Ncontainer to the high
Dialogue: 0,0:08:08.53,0:08:09.59,Default,,0000,0000,0000,,concentration container.
Dialogue: 0,0:08:09.59,0:08:11.13,Default,,0000,0000,0000,,So they diffused.
Dialogue: 0,0:08:11.13,0:08:12.82,Default,,0000,0000,0000,,This is diffusion.
Dialogue: 0,0:08:12.82,0:08:16.17,Default,,0000,0000,0000,,This is diffusion
Dialogue: 0,0:08:16.17,0:08:18.88,Default,,0000,0000,0000,,And just so that we learn some\Nother words that tend to be
Dialogue: 0,0:08:18.88,0:08:21.80,Default,,0000,0000,0000,,used with the idea of\Ndiffusion-- when we started
Dialogue: 0,0:08:21.80,0:08:24.26,Default,,0000,0000,0000,,off, this had a higher\Nconcentration.
Dialogue: 0,0:08:24.26,0:08:26.72,Default,,0000,0000,0000,,The left-hand side container\Nhad higher concentration.
Dialogue: 0,0:08:26.72,0:08:33.11,Default,,0000,0000,0000,,Higher concentration, higher concentration
Dialogue: 0,0:08:33.11,0:08:34.13,Default,,0000,0000,0000,,It's all relative, right?
Dialogue: 0,0:08:34.13,0:08:37.48,Default,,0000,0000,0000,,It's higher than this guy,higher concentration
Dialogue: 0,0:08:37.48,0:08:39.50,Default,,0000,0000,0000,,And this right here had\Na lower concentration.
Dialogue: 0,0:08:39.50,0:08:42.80,Default,,0000,0000,0000,,Lower concentrarion
Dialogue: 0,0:08:42.80,0:08:44.45,Default,,0000,0000,0000,,And there are words\Nfor these things.
Dialogue: 0,0:08:44.45,0:08:47.65,Default,,0000,0000,0000,,This solution with a high\Nconcentration is called a
Dialogue: 0,0:08:47.65,0:08:50.33,Default,,0000,0000,0000,,hypertonic solution.
Dialogue: 0,0:08:50.33,0:08:51.73,Default,,0000,0000,0000,,Let me write that in yellow.
Dialogue: 0,0:08:51.73,0:08:58.33,Default,,0000,0000,0000,,Hyoer, Hypertonic solution
Dialogue: 0,0:08:58.33,0:09:01.12,Default,,0000,0000,0000,,Hyper, in general, meaning\Nhaving a lot of something,
Dialogue: 0,0:09:01.12,0:09:02.62,Default,,0000,0000,0000,,having too much of something.
Dialogue: 0,0:09:02.62,0:09:05.92,Default,,0000,0000,0000,,And this lower concentration\Nis hypo, hypotonic
Dialogue: 0,0:09:05.92,0:09:13.72,Default,,0000,0000,0000,,Hypotonic solution,lower concentration
Dialogue: 0,0:09:13.72,0:09:16.66,Default,,0000,0000,0000,,You might have heard maybe one\Nof your relatives, if they
Dialogue: 0,0:09:16.66,0:09:20.73,Default,,0000,0000,0000,,haven't had a meal in awhile\Nsay, I'm hypoglycemic.
Dialogue: 0,0:09:20.73,0:09:22.23,Default,,0000,0000,0000,,That means that they have\Nnot-- they're feeling
Dialogue: 0,0:09:22.23,0:09:22.91,Default,,0000,0000,0000,,lightheaded.
Dialogue: 0,0:09:22.91,0:09:24.80,Default,,0000,0000,0000,,There's not enough sugar in\Ntheir bloodstream and they
Dialogue: 0,0:09:24.80,0:09:26.73,Default,,0000,0000,0000,,want to pass out so\Nthey want a meal.
Dialogue: 0,0:09:26.73,0:09:29.93,Default,,0000,0000,0000,,If you just had a candy bar,\Nmaybe you're hyperglycemic--
Dialogue: 0,0:09:29.93,0:09:32.93,Default,,0000,0000,0000,,or maybe you're just\Nhyper in general.
Dialogue: 0,0:09:32.93,0:09:35.58,Default,,0000,0000,0000,,But, so, you know, so these are just good\Nprefixes to know, but
Dialogue: 0,0:09:35.58,0:09:38.65,Default,,0000,0000,0000,,hypertonic-- you have\Na lot of the solute.
Dialogue: 0,0:09:38.65,0:09:40.51,Default,,0000,0000,0000,,You have a high concentration.
Dialogue: 0,0:09:40.51,0:09:44.50,Default,,0000,0000,0000,,And then in hypotonic, not too\Nmuch of the solute so you have
Dialogue: 0,0:09:44.50,0:09:46.01,Default,,0000,0000,0000,,a low concentration.
Dialogue: 0,0:09:46.01,0:09:47.13,Default,,0000,0000,0000,,These are good words to know.
Dialogue: 0,0:09:47.13,0:09:51.22,Default,,0000,0000,0000,,So in general, diffusion-- if\Nthere's no barriers to the
Dialogue: 0,0:09:51.22,0:09:54.79,Default,,0000,0000,0000,,diffusion like we had here, you\Nwill have the solute go
Dialogue: 0,0:09:54.79,0:09:58.82,Default,,0000,0000,0000,,from a high concentration or\Nhypertonic solution if they
Dialogue: 0,0:09:58.82,0:10:03.49,Default,,0000,0000,0000,,can travel to a hypotonic\Nsolution, to a hypo, where the
Dialogue: 0,0:10:03.49,0:10:05.52,Default,,0000,0000,0000,,concentration is lower.
Dialogue: 0,0:10:05.52,0:10:08.48,Default,,0000,0000,0000,,Now let's do an interesting\Nexperiment here.
Dialogue: 0,0:10:08.48,0:10:10.93,Default,,0000,0000,0000,,We've talked about diffusion and\Nso far we've been talking
Dialogue: 0,0:10:10.93,0:10:14.53,Default,,0000,0000,0000,,about the diffusion of\Nthe solute, right?
Dialogue: 0,0:10:14.53,0:10:17.77,Default,,0000,0000,0000,,And in general-- and this is not\Nalways the case-- if you
Dialogue: 0,0:10:17.77,0:10:19.78,Default,,0000,0000,0000,,want to be as general as\Npossible, the solute is
Dialogue: 0,0:10:19.78,0:10:22.40,Default,,0000,0000,0000,,whatever you have less of,\Nthe solvent is whatever
Dialogue: 0,0:10:22.40,0:10:23.51,Default,,0000,0000,0000,,you have more of.
Dialogue: 0,0:10:23.51,0:10:26.60,Default,,0000,0000,0000,,And the most common solvent\Ntends to be water, but it
Dialogue: 0,0:10:26.60,0:10:27.52,Default,,0000,0000,0000,,doesn't have to be water.
Dialogue: 0,0:10:27.52,0:10:28.87,Default,,0000,0000,0000,,It could be some type\Nof alcohol.
Dialogue: 0,0:10:28.87,0:10:31.39,Default,,0000,0000,0000,,It could be a...you, know it could be mercury.
Dialogue: 0,0:10:31.39,0:10:34.88,Default,,0000,0000,0000,,It could be a whole set of\Nmolecules, but water in most
Dialogue: 0,0:10:34.88,0:10:38.13,Default,,0000,0000,0000,,biological or chemical systems\Ntends to be the
Dialogue: 0,0:10:38.13,0:10:39.46,Default,,0000,0000,0000,,most typical solvent.
Dialogue: 0,0:10:39.46,0:10:41.92,Default,,0000,0000,0000,,It's what other things\Nare dissolved into.
Dialogue: 0,0:10:41.92,0:10:46.38,Default,,0000,0000,0000,,But what happens if we have a\Ntunnel where the solute is too
Dialogue: 0,0:10:46.38,0:10:51.06,Default,,0000,0000,0000,,big to travel, but water is\Nsmall enough to travel?
Dialogue: 0,0:10:51.06,0:10:55.37,Default,,0000,0000,0000,,Let's think about\Nthat situation, let's think about the situation
Dialogue: 0,0:10:55.37,0:10:57.09,Default,,0000,0000,0000,,In order to think about it,\NI'm going to do something
Dialogue: 0,0:10:57.09,0:10:58.83,Default,,0000,0000,0000,,interesting.
Dialogue: 0,0:10:58.83,0:11:02.67,Default,,0000,0000,0000,,Let's say we have a\Ncontainer here,let's say
Dialogue: 0,0:11:02.67,0:11:03.95,Default,,0000,0000,0000,,Actually, I won't even\Ndraw a container.
Dialogue: 0,0:11:03.95,0:11:07.19,Default,,0000,0000,0000,,Let's just say we have an\Noutside environment that has a
Dialogue: 0,0:11:07.19,0:11:09.26,Default,,0000,0000,0000,,bunch of water.
Dialogue: 0,0:11:09.26,0:11:12.63,Default,,0000,0000,0000,,This is the outside environment\Nand then you have
Dialogue: 0,0:11:12.63,0:11:13.88,Default,,0000,0000,0000,,some type of membrane.
Dialogue: 0,0:11:13.88,0:11:19.40,Default,,0000,0000,0000,,you have some type of membrane here, that's a membrane
Dialogue: 0,0:11:19.40,0:11:22.04,Default,,0000,0000,0000,,Water can go in and out\Nof this membrane.
Dialogue: 0,0:11:22.04,0:11:23.19,Default,,0000,0000,0000,,So it's semi-permeable.
Dialogue: 0,0:11:23.19,0:11:26.52,Default,,0000,0000,0000,,Well, it's permeable to water,\Nbut the solute cannot go
Dialogue: 0,0:11:26.52,0:11:27.11,Default,,0000,0000,0000,,through the membrane.
Dialogue: 0,0:11:27.11,0:11:28.68,Default,,0000,0000,0000,,So let's say that the\Nsolute is sugar.
Dialogue: 0,0:11:28.68,0:11:33.06,Default,,0000,0000,0000,,So we have water on\Nthe outside and
Dialogue: 0,0:11:33.06,0:11:36.13,Default,,0000,0000,0000,,also inside the membrane.
Dialogue: 0,0:11:36.13,0:11:39.38,Default,,0000,0000,0000,,So these are little small\Nwater molecules.
Dialogue: 0,0:11:39.38,0:11:43.95,Default,,0000,0000,0000,,This is a membrane right here.
Dialogue: 0,0:11:43.95,0:11:46.52,Default,,0000,0000,0000,,And let's say that we have some\Nsugar molecules again--
Dialogue: 0,0:11:46.52,0:11:47.56,Default,,0000,0000,0000,,I'm just picking on sugar.
Dialogue: 0,0:11:47.56,0:11:48.76,Default,,0000,0000,0000,,It could have been anything.
Dialogue: 0,0:11:48.76,0:11:51.05,Default,,0000,0000,0000,,So we have some sugar molecules\Nhere that are just a
Dialogue: 0,0:11:51.05,0:11:55.95,Default,,0000,0000,0000,,little bit bigger-- or they\Ncould be a lot bigger.
Dialogue: 0,0:11:55.95,0:11:57.75,Default,,0000,0000,0000,,Actually, they're a lot bigger\Nthan water molecules.
Dialogue: 0,0:11:57.75,0:11:59.70,Default,,0000,0000,0000,,You have a bunch of-- and I only\Ndraw four, but you have a
Dialogue: 0,0:11:59.70,0:12:01.21,Default,,0000,0000,0000,,gazillion of them, right?
Dialogue: 0,0:12:01.21,0:12:03.47,Default,,0000,0000,0000,,You have that much more\Nwater molecules.
Dialogue: 0,0:12:03.47,0:12:05.32,Default,,0000,0000,0000,,I'm just trying to show you have\Nmore water molecules than
Dialogue: 0,0:12:05.32,0:12:06.29,Default,,0000,0000,0000,,sugar molecules.
Dialogue: 0,0:12:06.29,0:12:07.64,Default,,0000,0000,0000,,And this membrane is\Nsemi-permeable.
Dialogue: 0,0:12:13.14,0:12:15.21,Default,,0000,0000,0000,,Permeable means it allows\Nthings to pass.
Dialogue: 0,0:12:15.21,0:12:18.07,Default,,0000,0000,0000,,Semi-permeables means it's\Nnot completely permeable.
Dialogue: 0,0:12:18.07,0:12:20.65,Default,,0000,0000,0000,,So semi-permeable-- in this\Ncontext, I'm saying I allow
Dialogue: 0,0:12:20.65,0:12:22.44,Default,,0000,0000,0000,,water to pass through\Nthe membrane.
Dialogue: 0,0:12:22.44,0:12:28.85,Default,,0000,0000,0000,,So water can pass,\Nbut sugar cannot.
Dialogue: 0,0:12:28.85,0:12:30.10,Default,,0000,0000,0000,,Sugar is too large.
Dialogue: 0,0:12:35.90,0:12:39.22,Default,,0000,0000,0000,,So if we were to zoom in on the\Nactual membrane itself--
Dialogue: 0,0:12:39.22,0:12:40.58,Default,,0000,0000,0000,,maybe the membrane\Nlooks like this.
Dialogue: 0,0:12:40.58,0:12:41.98,Default,,0000,0000,0000,,I'm going to zoom in\Non this membrane.
Dialogue: 0,0:12:44.53,0:12:48.62,Default,,0000,0000,0000,,So it has little holes in the\Nmembrane, just like that.
Dialogue: 0,0:12:48.62,0:12:51.27,Default,,0000,0000,0000,,And maybe the water molecules\Nare about that size.
Dialogue: 0,0:12:51.27,0:12:53.82,Default,,0000,0000,0000,,So they can go through\Nthose holes.
Dialogue: 0,0:12:53.82,0:12:56.25,Default,,0000,0000,0000,,So the water molecules can go\Nback and forth through the
Dialogue: 0,0:12:56.25,0:13:01.52,Default,,0000,0000,0000,,holes, but the sugar molecules\Nare about that big.
Dialogue: 0,0:13:01.52,0:13:04.99,Default,,0000,0000,0000,,So they cannot go through\Nthat hole.
Dialogue: 0,0:13:04.99,0:13:07.28,Default,,0000,0000,0000,,They're too big for this opening\Nright here to go back
Dialogue: 0,0:13:07.28,0:13:08.83,Default,,0000,0000,0000,,and forth between them.
Dialogue: 0,0:13:08.83,0:13:12.68,Default,,0000,0000,0000,,Now what do you think is going\Nto happen in this situation?
Dialogue: 0,0:13:12.68,0:13:14.33,Default,,0000,0000,0000,,So first of all, let's\Nuse our terminology.
Dialogue: 0,0:13:14.33,0:13:15.72,Default,,0000,0000,0000,,Remember, sugar is our solute.
Dialogue: 0,0:13:15.72,0:13:17.12,Default,,0000,0000,0000,,Water is our solvent.
Dialogue: 0,0:13:17.12,0:13:18.93,Default,,0000,0000,0000,,Semi-permeable membrane.
Dialogue: 0,0:13:18.93,0:13:21.40,Default,,0000,0000,0000,,Which side of the membrane\Nhas a higher or lower
Dialogue: 0,0:13:21.40,0:13:24.33,Default,,0000,0000,0000,,concentration of solute?
Dialogue: 0,0:13:24.33,0:13:25.69,Default,,0000,0000,0000,,Well, the inside does.
Dialogue: 0,0:13:25.69,0:13:27.06,Default,,0000,0000,0000,,The inside is hypertonic.
Dialogue: 0,0:13:32.37,0:13:33.54,Default,,0000,0000,0000,,The outside has a lower
Dialogue: 0,0:13:33.54,0:13:34.85,Default,,0000,0000,0000,,concentration so it's hypotonic.
Dialogue: 0,0:13:44.85,0:13:47.68,Default,,0000,0000,0000,,Now, if these openings were big\Nenough, based on what we
Dialogue: 0,0:13:47.68,0:13:51.33,Default,,0000,0000,0000,,just talked about-- these guys\Nare bouncing around, water is
Dialogue: 0,0:13:51.33,0:13:53.70,Default,,0000,0000,0000,,travelling in either direction,\Nand equal
Dialogue: 0,0:13:53.70,0:13:56.52,Default,,0000,0000,0000,,probability or-- actually\NI'm going to talk
Dialogue: 0,0:13:56.52,0:13:58.36,Default,,0000,0000,0000,,about that in a second.
Dialogue: 0,0:13:58.36,0:14:01.66,Default,,0000,0000,0000,,If everything was wide open, it\Nwould be equal probability,
Dialogue: 0,0:14:01.66,0:14:03.78,Default,,0000,0000,0000,,but if it was wide open, these\Nguys eventually would bounce
Dialogue: 0,0:14:03.78,0:14:06.45,Default,,0000,0000,0000,,their ways over to this side and\Nyou'd probably end up with
Dialogue: 0,0:14:06.45,0:14:08.50,Default,,0000,0000,0000,,equal concentrations\Neventually.
Dialogue: 0,0:14:08.50,0:14:10.71,Default,,0000,0000,0000,,And so you would have your\Ntraditional diffusion, where
Dialogue: 0,0:14:10.71,0:14:13.13,Default,,0000,0000,0000,,high concentration\Nof solute to low
Dialogue: 0,0:14:13.13,0:14:14.53,Default,,0000,0000,0000,,concentrations of solute.
Dialogue: 0,0:14:14.53,0:14:17.35,Default,,0000,0000,0000,,But in this case, these\Nguys-- they can't
Dialogue: 0,0:14:17.35,0:14:18.33,Default,,0000,0000,0000,,fit through the hole.
Dialogue: 0,0:14:18.33,0:14:20.16,Default,,0000,0000,0000,,Only water can go\Nback and forth.
Dialogue: 0,0:14:20.16,0:14:25.18,Default,,0000,0000,0000,,If these guys were not here,\Nwater would have an equal
Dialogue: 0,0:14:25.18,0:14:28.78,Default,,0000,0000,0000,,likelihood of going in this\Ndirection as they would be
Dialogue: 0,0:14:28.78,0:14:33.94,Default,,0000,0000,0000,,going in that direction, a\Ncompletely equal likelihood.
Dialogue: 0,0:14:33.94,0:14:40.09,Default,,0000,0000,0000,,But because these guys are on\Nthe right-hand side of-- or in
Dialogue: 0,0:14:40.09,0:14:42.29,Default,,0000,0000,0000,,this case, on the inside\Nof our membrane.
Dialogue: 0,0:14:42.29,0:14:47.00,Default,,0000,0000,0000,,This is our inside of our\Nmembrane zoomed up-- it's less
Dialogue: 0,0:14:47.00,0:14:50.44,Default,,0000,0000,0000,,likely because these guys\Nmight be in the approach
Dialogue: 0,0:14:50.44,0:14:55.23,Default,,0000,0000,0000,,position of the holes-- that's\Nslightly less likely for water
Dialogue: 0,0:14:55.23,0:14:58.11,Default,,0000,0000,0000,,to be in the approach position\Nfor the holes so it's actually
Dialogue: 0,0:14:58.11,0:15:02.72,Default,,0000,0000,0000,,more probable that water could\Nenter than water exit.
Dialogue: 0,0:15:02.72,0:15:04.18,Default,,0000,0000,0000,,And I want to make\Nthat very clear.
Dialogue: 0,0:15:04.18,0:15:07.15,Default,,0000,0000,0000,,If these sugar molecules were\Nnot here, obviously it's
Dialogue: 0,0:15:07.15,0:15:09.83,Default,,0000,0000,0000,,equally likely for water to\Ngo in either direction.
Dialogue: 0,0:15:09.83,0:15:12.73,Default,,0000,0000,0000,,Now that these sugar molecules\Nare there, these sugar
Dialogue: 0,0:15:12.73,0:15:15.29,Default,,0000,0000,0000,,molecules might be on\Nthe right-hand side.
Dialogue: 0,0:15:15.29,0:15:18.20,Default,,0000,0000,0000,,They might be blocking-- I guess\Nthe best way to think
Dialogue: 0,0:15:18.20,0:15:20.43,Default,,0000,0000,0000,,about it is blocking the\Napproach to the hole.
Dialogue: 0,0:15:20.43,0:15:22.06,Default,,0000,0000,0000,,They'll never be able to go\Nthrough the hole themselves
Dialogue: 0,0:15:22.06,0:15:24.49,Default,,0000,0000,0000,,and might not even be blocking\Nthe hole, but they're going in
Dialogue: 0,0:15:24.49,0:15:25.72,Default,,0000,0000,0000,,some random direction.
Dialogue: 0,0:15:25.72,0:15:29.58,Default,,0000,0000,0000,,So if a water molecule was\Napproaching-- it's all
Dialogue: 0,0:15:29.58,0:15:31.36,Default,,0000,0000,0000,,probabilistic and we're dealing\Nwith gazillions of
Dialogue: 0,0:15:31.36,0:15:34.61,Default,,0000,0000,0000,,molecules-- it's that much more\Nlikely to be blocked to
Dialogue: 0,0:15:34.61,0:15:35.36,Default,,0000,0000,0000,,get outside.
Dialogue: 0,0:15:35.36,0:15:37.62,Default,,0000,0000,0000,,But the water molecules from the\Noutside-- there's nothing
Dialogue: 0,0:15:37.62,0:15:40.17,Default,,0000,0000,0000,,blocking them to get in so\Nyou're going to have a flow of
Dialogue: 0,0:15:40.17,0:15:41.48,Default,,0000,0000,0000,,water inside.
Dialogue: 0,0:15:41.48,0:15:44.31,Default,,0000,0000,0000,,So in this situation, with a\Nsemi-permeable membrane,
Dialogue: 0,0:15:44.31,0:15:45.70,Default,,0000,0000,0000,,you're going to have water.
Dialogue: 0,0:15:45.70,0:15:49.28,Default,,0000,0000,0000,,You're going to have a net\Ninward flow of water.
Dialogue: 0,0:15:49.28,0:15:51.43,Default,,0000,0000,0000,,And so this is kind\Nof interesting.
Dialogue: 0,0:15:51.43,0:15:56.90,Default,,0000,0000,0000,,We have the solvent flowing from\Na hypotonic situation to
Dialogue: 0,0:15:56.90,0:15:59.60,Default,,0000,0000,0000,,a hypertonic solution,\Nbut it's only
Dialogue: 0,0:15:59.60,0:16:01.21,Default,,0000,0000,0000,,hypotonic in the solute.
Dialogue: 0,0:16:07.65,0:16:11.62,Default,,0000,0000,0000,,But water-- if you flip it the\Nother way-- if you've used
Dialogue: 0,0:16:11.62,0:16:15.29,Default,,0000,0000,0000,,sugar as the solvent, then you\Ncould say, we're going from a
Dialogue: 0,0:16:15.29,0:16:19.47,Default,,0000,0000,0000,,high concentration of water to\Na low concentration of water.
Dialogue: 0,0:16:19.47,0:16:20.37,Default,,0000,0000,0000,,I don't want to confuse\Nyou too much.
Dialogue: 0,0:16:20.37,0:16:23.09,Default,,0000,0000,0000,,This is what tends to confuse\Npeople, but just think about
Dialogue: 0,0:16:23.09,0:16:24.04,Default,,0000,0000,0000,,what's going to happen.
Dialogue: 0,0:16:24.04,0:16:27.26,Default,,0000,0000,0000,,No matter in what situation,\Nthe solution is going to do
Dialogue: 0,0:16:27.26,0:16:30.00,Default,,0000,0000,0000,,what it can to try to\Nequilibriate the
Dialogue: 0,0:16:30.00,0:16:30.68,Default,,0000,0000,0000,,concentration.
Dialogue: 0,0:16:30.68,0:16:32.08,Default,,0000,0000,0000,,To make the concentrations\Non both
Dialogue: 0,0:16:32.08,0:16:33.71,Default,,0000,0000,0000,,sides as close as possible.
Dialogue: 0,0:16:33.71,0:16:35.15,Default,,0000,0000,0000,,And it's not just some magic.
Dialogue: 0,0:16:35.15,0:16:36.16,Default,,0000,0000,0000,,It's not like the\Nsolution knows.
Dialogue: 0,0:16:36.16,0:16:38.30,Default,,0000,0000,0000,,It's all based on probabilities\Nand these things
Dialogue: 0,0:16:38.30,0:16:41.05,Default,,0000,0000,0000,,bumping around, but in this\Nsituation, water is more
Dialogue: 0,0:16:41.05,0:16:43.79,Default,,0000,0000,0000,,likely to flow into\Nthe container.
Dialogue: 0,0:16:43.79,0:16:46.70,Default,,0000,0000,0000,,So it's actually going to go\Nfrom the hypotonic side when
Dialogue: 0,0:16:46.70,0:16:50.46,Default,,0000,0000,0000,,we talk about low concentration\Nof solute to the
Dialogue: 0,0:16:50.46,0:16:53.69,Default,,0000,0000,0000,,side that has high\Nconcentrations of solute, of
Dialogue: 0,0:16:53.69,0:16:57.32,Default,,0000,0000,0000,,sugar-- and actually, if this\Nthing is stretchable, more
Dialogue: 0,0:16:57.32,0:17:01.67,Default,,0000,0000,0000,,water will keep flowing\Nin and this membrane
Dialogue: 0,0:17:01.67,0:17:04.42,Default,,0000,0000,0000,,will stretch out.
Dialogue: 0,0:17:04.42,0:17:08.42,Default,,0000,0000,0000,,I won't go to too much detail\Nhere, but this idea of water--
Dialogue: 0,0:17:08.42,0:17:12.47,Default,,0000,0000,0000,,of the solvent-- if in this\Ncase, water is the solvent--
Dialogue: 0,0:17:12.47,0:17:15.15,Default,,0000,0000,0000,,of water as a solvent\Ndiffusing through a
Dialogue: 0,0:17:15.15,0:17:18.50,Default,,0000,0000,0000,,semi-permeable membrane,\Nthis is called osmosis.
Dialogue: 0,0:17:22.57,0:17:25.17,Default,,0000,0000,0000,,You've probably heard learning\Nby osmosis-- if you put a book
Dialogue: 0,0:17:25.17,0:17:27.20,Default,,0000,0000,0000,,against your head, maybe it'll\Njust seep into your brain.
Dialogue: 0,0:17:27.20,0:17:28.00,Default,,0000,0000,0000,,Same idea.
Dialogue: 0,0:17:28.00,0:17:29.50,Default,,0000,0000,0000,,That's where the word\Ncomes from.
Dialogue: 0,0:17:29.50,0:17:33.57,Default,,0000,0000,0000,,This idea of water seeping\Nthrough membranes to try to
Dialogue: 0,0:17:33.57,0:17:35.60,Default,,0000,0000,0000,,make concentrations\Nmore equal.
Dialogue: 0,0:17:35.60,0:17:38.37,Default,,0000,0000,0000,,So if you say, well, I have high\Nconcentration here, low
Dialogue: 0,0:17:38.37,0:17:39.49,Default,,0000,0000,0000,,concentration here.
Dialogue: 0,0:17:39.49,0:17:43.02,Default,,0000,0000,0000,,If there was no membrane here,\Nthese big molecules would
Dialogue: 0,0:17:43.02,0:17:48.08,Default,,0000,0000,0000,,exit, but because there's this\Nsemi-permeable membrane here,
Dialogue: 0,0:17:48.08,0:17:48.68,Default,,0000,0000,0000,,they can't.
Dialogue: 0,0:17:48.68,0:17:52.40,Default,,0000,0000,0000,,So the system just\Nprobabilistically-- no magic
Dialogue: 0,0:17:52.40,0:17:56.09,Default,,0000,0000,0000,,here-- more water will enter\Nto try to equilibriate
Dialogue: 0,0:17:56.09,0:17:57.16,Default,,0000,0000,0000,,concentration.
Dialogue: 0,0:17:57.16,0:18:01.97,Default,,0000,0000,0000,,Eventually-- if maybe there's a\Nfew molecules out here-- not
Dialogue: 0,0:18:01.97,0:18:06.44,Default,,0000,0000,0000,,as high concentration here--\Neventually if everything was
Dialogue: 0,0:18:06.44,0:18:08.97,Default,,0000,0000,0000,,allowed to happen fully, you'll\Nget to the point where
Dialogue: 0,0:18:08.97,0:18:11.12,Default,,0000,0000,0000,,you have just as many--\Nyou have just as high
Dialogue: 0,0:18:11.12,0:18:13.65,Default,,0000,0000,0000,,concentration on this side as\Nyou have on the right-hand
Dialogue: 0,0:18:13.65,0:18:16.50,Default,,0000,0000,0000,,side because this right-hand\Nside is going to fill with
Dialogue: 0,0:18:16.50,0:18:19.38,Default,,0000,0000,0000,,water and also probably become\Na larger volume.
Dialogue: 0,0:18:19.38,0:18:21.52,Default,,0000,0000,0000,,And then, once again, the\Nprobabilities of a water
Dialogue: 0,0:18:21.52,0:18:23.60,Default,,0000,0000,0000,,molecule going to the right and\Nto the left will be the
Dialogue: 0,0:18:23.60,0:18:25.92,Default,,0000,0000,0000,,same and you'll get to some\Ntype of equilibrium.
Dialogue: 0,0:18:25.92,0:18:29.91,Default,,0000,0000,0000,,But I want to make it very\Nclear-- diffusion is the idea
Dialogue: 0,0:18:29.91,0:18:33.13,Default,,0000,0000,0000,,of any particle going from\Nhigher concentration and
Dialogue: 0,0:18:33.13,0:18:35.74,Default,,0000,0000,0000,,spreading into a region that has\Na lower concentration and
Dialogue: 0,0:18:35.74,0:18:36.95,Default,,0000,0000,0000,,just spreading out.
Dialogue: 0,0:18:36.95,0:18:41.24,Default,,0000,0000,0000,,Osmosis is the diffusion\Nof water.
Dialogue: 0,0:18:41.24,0:18:44.21,Default,,0000,0000,0000,,And usually you're talking about\Nthe diffusion of water
Dialogue: 0,0:18:44.21,0:18:47.01,Default,,0000,0000,0000,,as a solvent and usually it's\Nin the context of a
Dialogue: 0,0:18:47.01,0:18:51.26,Default,,0000,0000,0000,,semi-permeable membrane, where\Nthe actual solute cannot
Dialogue: 0,0:18:51.26,0:18:53.53,Default,,0000,0000,0000,,travel through the membrane.
Dialogue: 0,0:18:53.53,0:18:55.80,Default,,0000,0000,0000,,Anyway, hopefully you've\Nfound that useful and
Dialogue: 0,0:18:55.80,0:18:57.88,Default,,0000,0000,0000,,not completely confusing.