Why don't oil and water mix? - John Pollard
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- Опубліковано 15 жов 2024
- View full lesson: ed.ted.com/less...
Salt dissolves in water; oil does not. But why? You can think of that glass of water as a big, bumpin' dance party where the water molecules are always switching dance partners -- and they'd much rather dance with a salt ion. John Pollard explains how two chemistry principles, energetics and entropy, rule the dance floor.
Lesson by John Pollard, animation by Andrew Foerster.
This guy went so deep into the analogy that I have no idea how it actually works.
exactly
+SpectreD41 Basically he pointed out that the oil molecules are way more bigger than water molecules, so they cannot join together.
+Minh Phạm Which isn't true.
+Professor Tenebrae so how does that works?
salem hjouj It's a mix of density, the size of the molecules in this case is what affects density, and the fact that parts of the oil molecule are 'hydrophobic'. This is essentially what he's saying.
The non-polar, larger oil molecules would mix with water, but they attract themselves and repel water due to these hydrophobic properties, then the lower density causes it to float to the top. This is why when you add emulsifier to a mix of oil and water which removes oils hydrophobic tendencies by introducing even more polar molecules. Ones that attracted to oil, and water, causing it to rip the oil apart into smaller parts to mix with the water. Different emulsifiers of different strengths do this in different ways. www.aocs.org/Membership/FreeCover.cfm?ItemNumber=19406
I've learned some pretty advanced stuff with simplified analogy, but this is way too metaphorical for me to extract any hard science information.
The dance is a metaphor for how water molecules interact in the liquid phase. The available ways water molecules arrange through random motion is dictated heavily by the hydrogen-bonding interactions. Any event that organizes water molecules or disrupts the H-bonding network reduces the "entropy" of that system. The entropy is the measure of how many different configurations, through random motion, a system adopts....and entropy always favors states where more configurations are available. For water, this is the H-bonding dance configurations. Oil has an attractive force with water but disrupts the overall H-bonding dance...or lowers the entropy. This is unfavored by random motion so the oil molecules are pushed out. Entropy is why they do not mix.
***** Your more advanced explanation is good Xavier. In the analogy of the video, the number of microstates available is related to the ability of the molecules to dance with each other. Water molecules have many more options for "dance moves" with themselves than if oil is mixed in. It isn't the attractive forces that is the issue but the available ways to arrange and distribute energy through interactions that causes the separation...hence they are not good dance partners meaning the entropy is higher when they separate. Thanks for your contribution! Most of the criticism of the video seems to come from people who do not understand the underlying idea. Most people think the separation arises from attractive forces, not entropy.
Exactly...wAAAAy too much. now i can not even imagine the look on my chemistry sirs face if i give him this in a viva......LOL
John Pollard
The point being, your metaphor gets in the way. You keep having to explain what the metaphor refers to, which means the metaphor isn't working.
What?
How could you dumb down something so much to the point where you don't understand anything
Tijana Bojic so did you take any chemistry class? If you didn't then just know that it is not how they mix. The video is really dumb
Maybe this video was meant to be shown to sixth graders or something.
Either you're all really stupid, or just dicks toward younger kids
I didn't say anything bad about kids, I just said this video is probably meant to be used by science teachers who are introducing chemistry or something. However, I'm not sure why they have to do this entire story and couldn't just give it to us straight.
Grave Digger It isn't "how", the question answered here is "why".
teacher:do you know why water and oil are not mixing?
student:because oils are terrible dancer
Paul John Aguilar lol
Agreed
You forgot the third dialogue.
teacher: Get out.
And/Or
teacher: Bring your parents to see me tomorrow.
@Paul John Aguilar and, they have giant ball gown dresses 👗
Yeet
The writer was all "They're square dancing", the animator however decided, "Screw that, it's a disco."
AHAHAHHAAAHAHHAH
AHAHAHHAAAHAHHAH
AHAHHAHHAHAAA
no
with DJ ENTROPY at 2:34
Well, the analogy wasn't wrong at all but I just understood something because I was previously reading about it, but those who don't really know did get confused because well... Practically nothing was explained here.
True ,I watched the video to enhance what I learned but I got out of it more confused than ever.
I am watching this for the second time and agree that he should have been more literal and less childish, but it actually is helpful if you know the concept already and can take into account oil as disrupting entropy and salt as increasing it. Just the technique employed here wasn't very satisfactory.
i dont mind analogies but this... this is too MUCH!
That is not analogy check the term in dictionary and to much is a term that is used only for the professional team. In chemistry lab they have measures- therefore to much term can not be used in chemistry. They have eprubets that measures everything So what is your comment point?
Ya take that Nam, read a dictionary nerd.
We got him @Emma we'll never let someone speak their opinion
You made simple thing complex.
"Water and oil don't mix because they just don't make good dance partners." WHAT THE FUCK.
Vianca Varma omg that comment killed me 😂😂😂
Vianca Varma omg that comment killed me 😂😂😂
Vianca Varma
Purpose of the dance part: Constant entropy
What they mean by bad dancers: They reduce entropy (the polarity keeps them from molecularly bonding with water so the closest they can get is to make small oil clusters spaced out in the water)
Maybe chocolate milk explains it better. There isn't a chocolate milk molecule; there is chocolate syrup and milk but not a combined molecule (not a solution but a mixture). So basically the syrup clumps move around until they recluster. You can of course artificially mix them by shaking/stirring it but that's besides the point.
Result: The oil is moved away to make more possible water combinations (entropy)
That's what I got out of it, someone correct me if I'm wrong. I'd rather be told the right thing and look like an idiot then go on believing lies.
Nathan Edwards your understanding of the concept is valid don't worry
This is more of a metaphor than an analogy. The difference is that, in an analogy, you explain something, then compare it to something else to make it easier to understand. In a metaphor, you just say something figurative and the person listening has to already know what you're talking about in order to understand.
So, in my point of view, it isn't very efficient to make an "educational metaphor", which is what this video essentially is.
I love how creative this is. It shows us a different way of thinking. It's like taking book knowledge and grasping it with your mind. It helps you to not memorize, but really learn how things work :)
this video was garbage, the analogy went so deep i didnt learn anything except that oil wears a dress and water doesnt want to dance because of it
Earls Log Capuchin omg I am dying! 😂😂😂
LMFAOOO
hello there General Kenobi!
It's boring
😬🤣🤣
I think this would have been much more simpler if you went into actual detail as opposed to telling a children's story
true smh..
Yeah I appreciate it.
I don't mind when analogies are used to help describe scientific concepts, but this is just too much.
if you hate metaphors here is a short answer
the oil molecules are too big to mix with the water molecules
Nice
even that isn’t the reason water doesn’t mix with oil... salt molecules are much bigger than water molecules but they still mix. basically, it’s like magnetism; water molecules are like magnets and they have poles, yet oil does not. since oil has no poles for water to be attracted to, water stays away from the oil, and therefore doesn’t mix.
@@anonymouscheesepie3768 Nicer
The reason this video is so weird is because it’s trying to explain why we should believe mixing oil and water is a more ordered state than having them separate. It’s totally unintuitive but apparently it’s true. It takes work to mix oil and water and heat is released when they separate - even though it looks more random to the eye when they are mixed it is actually more random the other way.
@@anonymouscheesepie3768 Polarity is not the reason either, we just tell kids that because it is easier to explain that way. The real reason is much more non-intuitive: oil "orders" water and creates a more ordered structure akin to ice.
Sorry, but in this video the analogies got way out of hands and basically no real science is left in this video
I didn't know you watched this stuff.
Your description is incorrect on many levels. First, the attractive forces between molecules is not "magnetic", it is based on the distribution of electrons at any given time. Second, there are attractive forces between water and oil molecules which is the energetics. So that is also incorrect. The reason they do not mix is because there are more ways they can configure in space and distribute energy when unmixed. That is entropy and it is the driving force for them not mixing.
there ist definitely too much party in my glass of water
I cant even understand what are you talking about,I hope that you can just use the pro terms.......
I think the people who are interested in this video already got a certain level of chemistry knowledge.
Agreeably
I kno after 5 years..
@@mNandhu7 😂😂😂😂
very stupid analogy.
it said nothing about ion attractions or polarity.
+My Herpes Itch yeah! I was expecting a long explanation of electronegativity and polarity
+linouch ette but thats such an wishy washy chemist explanation too. I thought it started off so good with entropy but... meh...
+linouch ette but thats such an wishy washy chemist explanation too. I thought it started off so good with entropy but... meh...
The reason attractions and polarity were not emphasized is because they are not behind the reason that oil and water do not mix
If you really want more answers view the full lesson like the video says. There's a link in the description.
I loved this. As I watched this, it made me laugh because I could see the interactions between molecules happen in a dynamic way, and I could also relate it to the lessons I've been taught in chemistry. This is easy for less experienced people to understand and for more experienced people to see their knowledge applied in a different perspective.
Now, can you please explain this in chemistry? 😩😭
There is a elementary school chemistry. When you don’t understand the chemistry than what shall we do
Wait for it to rain
*reads title*
Oh I already know this but I'm watching it anyway
*watches video*
Ok I definitely didn't know /this/
I like how he used dancing to explain why oil and water don't mix.
Love the animation, too.
I don't get that super weird explaination
It actually sucks
@@bhaktaskitchen3510 r. I already know why they don't mix from chemistry class
The analogy is meant to create a visual for what entropy is on the molecular level (which is often misunderstood). Basically what the video is stating is that the mixed state of oil and water is of lower entropy than the unmixed state. So the non-mixing is driven by entropy not by the strength of attractive forces between molecules. The analogy is meant describe entropy which is not so easy when configurational stability leads to separation.
Oil floats on water.
Step 1: Wait for it to rain.
Step 2: Cover yourself in oil.
Step 3: Fly.
:)
Building off of what Sebastian posted, ΔH refers to the energetics, ΔS refers to the entropy and ΔG is a term that combines the two to make an overall prediction. With salt+water, ΔH is + meaning it is not favored by energetics so entropy (or configurations through random motion as the vid describes) is what drives salt to dissolve. For oi+water, the ΔH is nearly zero so it is the entropy that drives the two to separate...hence the analogy.
Those damn analogies.
"I'm not gonna tell you: The universe is like a ball on a spring. It's not" - Richard Feynman
Hydrophobicity is a word used to describe that things do not mix with water but it does not explain why they do not mix. Describing the polarity of molecules isn't actually needed to explain why they do not mix but I do appreciate the suggestion and that could be part of another video which applies polarity concepts to other observable things. Thanks.
Oil floats on water
1.Wait for rain
2.Cover yourself on oil
3.fly
This doesn't deserve this much hate, the analogy is good and the idea of the dance floor is brilliant. Kudos to John Pollard and Andrew Foerster
Obviously he's doing something right to have been used by TED Ed while you guys sit here and comment all day lol
What the heck you just said im so confuse
Maybe turn that 'to have' into 'because it has' cuz your comment is otherwise nonsense 😝
John Pollard just subbed my chem class, star struck?
Yeah I think I could have handled a little more science
Logan Carr yeah
Guys, basically, water molecules are moving. When sugar is mixed with water, the sugar breaks into small pieces and gets dragged by other water molecules, thus dissolving. The movement between water molecules is crucial, however oil molecules disruppt that, so water pushes the oil up to keep the bond. That is why they never mix
I think you are one of the few people who saw this video and actually seems to get it. Thanks.
"The problem is that the oil molecules are wearing gigantic ball gowns"
Oohhh, I see
They are a way to state that the oil molecules take up a lot of space on the dance floor. This is important because the size of oil molecules is an important factor to why the entropy is lowered when they enter water. There size disrupts the h-bonding network of water which is why they are, through random motion, pushed out. The dress analogy is meant to amplify their size. Good question.
*Oil Floats on water Flashbacks*
Yes, that is a more correct statement. The process is driven by entropy. I would say that the it is through random motion that the ions move into the water and do not reform the lattice. So, higher kinetic energy ions have sufficient energy when randomly colliding with water molecules to enter the h-bonding network and be solvated like you describe. That is a higher entropy state which means the probability of moving back to the lattice is very low. Good thinking kohyihung!
I don't see how anyone can not get lost somewhere along the analogy. When you're telling the analogy, you should explain what real-world concept each part of the analogy represents either during or after the analogy.
I think you missed what I meant by 'literally'. The molecules don't dance in the sense of having legs, arms and heads and moving around on a discofloor, oil molecules don't wear dresses and entropy isn't a disk jockey.
My point was that the analogy seemed to be more in focus than the principles it was trying to explain.
Great metaphor! It helped me apply scientific terms I am a bit familiar with in order to understand this topic.
so the answer I have to write in exam is they don't mix because they just don't make great partners
this was dumbed down too much I really could not understand... and I usually get it at the 1st watch
Kevin Everything 😂
I think the reason there are a lot of dislikes may be because a lot of people carry the misconception that polarity is an explanation for why they do not mix...which is incorrect. Entropy is the driving force for their separation so using polar/nonpolar would not be correct. The video is meant to use an analogy to illustrate entropy which is a tough concept.
Lesson learned: Water likes thin dancers, not *fat oily dancers*.
"salt dissolves in water"
step one: cover yourself in salt
step two: wait for it to rain
step three: disappear from existence
I came here to learn about chemistry. Instead, I learned nothing.
Well, the explanation is proper scientifically speaking. The parallel analogy is just a way to illustrate some of the concepts. The idea comes down to the fact that oil doesn't dissolve in water due to the mixed state being of lower entropy than the unmixed state. The analogy is meant to stress aspect of what entropy is for non-experts (which is commonly misunderstood).
This explanation gets lost in it's own analogy. Really terrible, sorry.
These adverts are killing my by the day
So... According to this, salt mixes with water because it can dance good and oil doesn't mix with water because it wears a huge gown and can't dance properly?
The emulsifier would be a molecule that can engage in the H-bonding dance with water AND effectively dance with oil. Using the analogy, the emulsifier would reduce the frustration that the water experiences with the large and poorly dancing oils being around AND reduces the bad feelings the oils have by being segregated by pulling them onto the dance floor in small groups to dance. The emulsifier is an extremely versatile dancer that helps oil and water mix. Again, it is driven by entropy.
If anyone wants to know how it actually works:
Short version- Water and oil create different types of bonds, so they can't mix.
Long version- Water creates a type of bond called hydrogen bond. In a hydrogen bond, the atom connected to the hydrogen (in this case, the oxygen) has a high electronegativity (it pulls electrons hard), which leaves the hydrogen effectively electronless, and therefore positive, while the oxygen gets two extra electrons and becomes negative.
NaCl (salt) is made out of positive Na ions and negative Cl ions. when they are in water the Na ions are attracted to the negative oxygen and the Cl ions are attracted to the positive hydrogens, so they seperate and mix with the water.
Oil, on the other hand, is held together by van der waals forces, which are affected by the number of electrons in a molecule and are not affected a lot by charge.
Soap creates both hydrogen bonds and van der waals interactions, so it can bond with both oil and water, so it can play the middleman and let oil dissolve in water.
Seriously TED, I already knew how this works and I had very little idea what you were talking about in the video.
Your explanation is actually incorrect. Your descriptions of the energetic aspects of the intermolecular interactions are good but the attractive forces are not why oil and water do not mix. You are missing the entropy part which is really the driving force for them not mixing. The video is meant to draw an analogy towards the entropic separation of the compounds. You have a common misconception that the attractive forces are what drive the separation. That is not true so Ted got it right here.
Good to know. I would have gotten that from the video if they just said that instead of drawing a convoluted analogy. It tells you something about a video when you learn more from the comments than the video itself.
BTW- incorrect ≠ incomplete. Since the energistics part is relevent and true, but not enough, that makes my explanation incomplete.
Ted Ed makes a mixture of knowledge and humor along with visual graphics which makes us grasp the concept and understand it at one glance. Thank you Ted Ed.
This one was a little too ELI5 for my tastes, the animation was nice however
Then you did not understand what energetics and entropy are. The analogy of them not being good dance partners is pointing out that oil molecules crowd water molecules within the hydrogen bonding network. Then through random motion, the water molecules push out the oils as there are more configurations (ways to dance) when they are out of the water (or dance floor).
This is the weirdest explanation ever. Seriously, what?
The problem is that the waters are not more attracted to each other than the oil. That is a misconception. The two are nearly equal in attraction and in fact because the water molecules are also attracted to the oil, it is the organizing of the water molecules around the oil molecules that is a reduction in entropy. The squeezing out is because to accommodate the larger oil, the water h-bonding is disrupted and through random motion the oil is squeezed out.
terrible lol.... only makes sense if you already understand lots of chemistry i think
Jordan Weir no just 13 yr old physics
I would be open to a better analogy. And I would also argue that it is true that building anthropomorphic explanations is not really scientific but they can be useful in building connections for tough concepts like entropy.
made no sense at all, water, salt and oil at a nightclub?
Well you see, when hydrochloric acid attempts to rob water in an ally way after the dance, the water pulls out its mace, which happens to be another dance club entirely, and spray his attacker in the hypothetical eyes.
I'm a chemist .. this cracked me up! I LOVED the oil ladies!! Snobs ... I would have explained it a little differently ... when two different substances are mixed together, as it was explained to me, when they are similar, like if they are polar or ionic (like salt), they "mix" because one substance can replace another at the molecular level, because they're similar thus they "dissolve" and can no longer be seen as separte. Oil and water are very different - oils are not polar and are made up of very long chains, where water is small and polar - so an oil molecule cannot replace and displace a water molecule next to itself so they stay separate and it never dissolves ... if I could use my hands and arms to explain, it would help!
TED-Ed too much of animation is distracting and makes it hard to make sense( science) out of it.
Animation helps some people understand the theory.
I actually agree that anthropomorphic descriptions are not directly scientific. But, they can be useful bridges to explaining more complex ideas like entropy. The scientific explanation could simply be put that they do not because because the mixed state is of lower entropy than the unmixed state. But to understand that (and this is directed towards younger students) you have to have an understanding of what entropy is and how it described as configurational stability can lead to separation.
if i write water and oil dont mix because they dont make great dance partners.... i will definitely fail with teacher laughing at my paper along with students
step 1. oil floats on water
step 2. wait for it to rain
step 3. cover yourself in oil
step 4. fly
not once did you even mention polarity and non-polarity.....
To sum it up:water has more mass and is denser than oil so oil floats on water
worst ted ed video I've watched
Faraz Ahmed more like special ed
Best ted ed video ever!
@@lionelmessi8380 more like that ain't even a little funny
Funniet I would say.🤣
The analogies in this video are top level
It's kinda amusing to see everyone in the comments being frustrated over the same thing as I am :D :D
This video got so oversimplified that it was actually harder for me to understand it. The entire time I had to convert the analogy into real scientific terms
Actually that is not why salt dissolves in water. The ions are actually more attracted to themselves than the water molecule based on an energetics argument alone salt would not dissolve. Therefore it is the number of configurations available to the salt ions when interacting in water (or the entropy increase) that is the driving force. But, what you say does explain how the ions interact through random motion when dissolved. It just doesn't explain why they dissolve. Good thinking!
*reads the title*
Me: Oh okay, it's gonna be interesting
*after watching the video*
Me: hmm...So that's what it is. Pfft Who am i kidding I did not Understand anything
May 2021 "Heaven Stairway" Incident
This is a bit silly. No mention of differing densities or hydrophylic/hydrophobic effects.
4:05 the guy at the back is a GREAT DANCER !
loved the metaphor...
I like your thinking Kiiastagan and you are correct. In this case (with oil and water) the entropic contribution to the change in free energy (which will be positive in this case) is dominant. The energetic contribution to the free energy turns out to not be the driving force for the separation which is the point of the video and analogy. You are right...it is stat mech and your english is not bad!
Simple. Oil has much density than water, that's why you can't mix oil to water.
There are many liquids which have different densities that do mix, so you are not correct.
Oh so that means that, every oil has a different density?
Don't take it a bad way, I'm trying to learn :P
No, it just means that the density difference is not what makes them not mix. Ethanol and water have different densities but mix very well.
No, it has to do with the intermolecular forces between water molecules and oil molecules.
I think the key is that oil does not ionize like salts do. Water is polar, so it dissolves compounds that ionize, especially into small ions like elements, better than something that doesn't. Water will weakly dissolve something polar, but if it ionizes, the charges are much stronger.
So since oil doesn't ionize and is non-polar, it's very inert in water and easily separated.
I have no damn of what so ever this guy is talking about. Only thing I understand is the title of the video.
It's due to emulsions. Oil and Water naturally separate out. When Oil is in Water, there are emulsifier molecules. The head of the emulsifier is hydrophilic and negatively charged, this means it likes water but hates oil. Where as the tail of the emulsifier is hydrophobic, meaning it hates water, but loves oil. Also oil droplets can't join together in water :)
DJ ENTROPY :)
Yes I understand what you are saying. I would add though that the explanation is built into the analogy but agree with you that an additional explanation that is non-anthropomorphic (non-analogy) could be expanded on. This video was meant as an intro to the topic. If you check out my UA-cam channel, I have a straight scientific explanation on a vid called "Let's Think about mixing...". And to others this is not "leeching"..because this TedEd video is mine as well! Thanks for your comments!
love the analogies great way to teach by relating to something most people do every week :)
Actually, the oil molecules do literally disrupt the hydrogen bonding network and that is behind why there is an entropy decrease if oil mixes. So, the oil molecules literally do disturb the dance.
Wow this is an amazing example I love it 😀
Substances with different densities can mix...it happens all the time. Ethanol and water mix very well and they have different densities.
Very Bad Analogy! Time has been wasTED.
Very funny joke
It should be noted that while the entropy of the system tends to go down when mixing oil and water at room temperature there is also strong temperature dependence to the entropy. As a result in hot water the entropy would go up upon mixing. The strong temperature dependence of the entropy however belies a strong temperature dependence of the energetics as well such that dissolution is opposed by energetics in hot water (and no the polarity of the two substances did not change). The final result is that oil is pretty insoluble over all temperatures, but at low temperatures it is opposed by entropy and favored by energy, but at high temperatures it is favored by entropy and opposed by energy. That is to say the heat capacity has a role to play as well!
Hank Ash Great comments Hank. Another way to think about what you are saying is to consider the dH of mixing which in general for "oil" and water is almost zero and the T effects (when thinking about the dG of mixing) are predominantly impacted by the difference in dH not dS. You can assume that in general the dS differences are greater over liquid water temps than dH. This is why the mixing does changes slightly over T changes but the entropy difference between the 2 states in the deciding factor. Thanks for contributing!
Very dissatisfying .
Im pretty sure it's the other way around, water molecules are polar so they attract each other, oil molecules are not polar so they are displaced as water ones get together. Salt's ions have strong attraction and this force can break into water.
So salts are ... Asian people????
hah!
LOL Asian people that come to America "never come back"
That is racist!!!!!!!
Ok, then here is your answer. The entropy of the system is higher when the oil and water do not mix vs. if they mix. The ball gown analogy is meant to emphasize the size of the oil molecules with reference to the water molecules. This is an important concept as the drop in entropy upon mixing is due to the crowding of water molecules leading to a lowering in the number of configurations because of disruption of the hydrogen bonding network. Watch it again and now think about it some more.
This was like a video not made by TED-Ed. It was horrible.
The ball gown is a lipid layer that it charged so I can't let molecules in or join others. Whereas a table salt or sodium chloride is much smaller and not charged carbon bound molecule that easily enters the uncharged surface layer of water
This is a stupid example
I think the thing to pay attention to is that the attractive forces between the ions and water and the oils molecules and water are not what is causing each to mix or not mix. It is the random motion that in the case of salt favors mixing (analogous to the components of air). The harder concept is that the same idea causes oil and water to separate. The dance analogy is meant to illustrate that aspect. Hope this makes more sense.