Make INSTANT Ice Cream! | Live Experiments with Jon Chase | Head Squeeze

[@21ninesco]

This video was awesome! I always see people add salt to ice in a container to make ice-cream, but I never really knew why they did it or how it worked. This video finally explained it really clearly. Thanks!

[@Cr125stin]

Hey I just made this for my mom and pops. They wanted some ice cream we were out and a few minutes later we had some! It came out great and super simple ! It was less that 10 min and we where eating. Thanks for the video

[@Mcryan2002]

awesome just tried it tastes awesome!

[@TheHuesSciTech]

You're spot on, it takes energy to go from a solid into a liquid. "Latent heat of fusion" is the term. It's 334 Joules per gram of water to freeze/melt. To shift liquid water by 1 degrees C, it's about 4.2 Joules. That means that there's 334 J / (4.2 J / K) = 79 degrees C "worth of extra coldness" (loosely speaking) in ice than in water. It takes a lot of energy to rip every single water molecule away from all its neighbours in the crystal.

[@mariyamharoon7961]

soo cool

[@angrycheez]

it does speed up the heat tranfer rate... the salt reduces the freezing point of water (hence the ice actually melts (it stays the same temperature) now as a liquid it has maximum surface area coverage in the bag (as ice there were pockets of air which greatly reduced the heat transfer rate). This high transfer rate makes it "feel" colder, but the actual temperature is the same with or without salt.

[@bucketslash11]

i love this guy, he is always so enthusiastic about the experiments :D

[@LEDiceGlacier]

The ice-cream tastes gorgeous. Nice one Jon.

[@mariyamharoon7961]

omg i tryed it and it worked soo cool

[@zsoltvarga4498]

I will try this! :D

[@noeandsomenumbers]

I did this, the bag pop'ed and we tasted some salty ice cream xD Time to try again.

[@pramitbanerjee]

at 0 degrees both can happen. The state changes depending on how the heat is being transferred, i.e energy must be supplied to the ice to melt it, which is what happens here.

[@marianopicco]

Antifreeze comes graded, you'll see in the bottle for which temperature its good for... usually around -10 degrees unless you buy a really good one cos you're in semi arctic parts of the world where they need lower temperatures, but it's more expensive

[@TheHuesSciTech]

Everything said in the video is correct. The energy of the system did not vanish, it went into melting a large portion of the ice. Once you factor in the latent heat of fusion, the energy mismatch disappears. As mentioned in my other posts on this video, the latent heat of ice is huge -- ice at 0°C has the same thermal energy as hypothetical supercooled water at *-80°C*. Even stealing all that energy from the milk and salt water, there's still not enough energy around to melt all the ice.

[@GaiusGaiusGaius]

love you Jon!!!

[@SEThatered]

Yes. Ice cubes have 0° on the surface where melting occurs, in the center in may be much colder. So when you lower the melting point, the solution now can conduct that inner temperature of ice cubes through liquid, and also have a bigger contact area for heat transfer: much more than a solid block of ice could have. Non salty water will always stay above 0° it's just physics law.

[@TheHuesSciTech]

Once its smoothly frozen, the crystal structure is fixed I believe. This is why store-bought ice-cream doesn't crystallize (except that thin layer on the lid, which actually melts and gets refreezed).

[@emeraldstars345]

We did this at school --- best chemistry experiment ever!!! Haha! :)

[@musanyamutamba3068]

Worked perfectly

[@FoxvoxDK]

LoL, I love how he says "th" as "fh" like "fhanks" and "fhousand". :D Also, yay ice cream! :O

[@BigDave41UK]

You're great Jon

[@Veronica-vn8te]

I did this in Grade 2, but with jars

[@marklewis662]

Have you thought about using dry ice for ice cream?

[@yanghuidt72]

What if you put in crushed up dry ice with more salt what would happen

[@JoshDangIt]

Black guy + British accent = best voice ever!

[@TheHuesSciTech]

All spot on, except its 334 *kilo*joules per kilogram. So you're off by a factor of 1000, which yields a temperature change of 79.8. That works out to a final temperature of -59.8, but of course, only some of the ice melts, it stops melting when -20 is reached. End result: ice/water mixture at -20.

[@Xtoffer87]

From the video, what i understood was salt allows the ice to turn back into water while retaining its temperature.

[@Muhovc]

Yeah, it stays at 0°C (or around 0°C) because the heat capacity of ice is different than water's. So at 0°C, ice becomes a mixure of ice and water ant the heat capacity of this mixture also changes with temperature. I agree with your last post, I don't see how it disagrees with anything I wrote.

[@angrycheez]

check out a video from minutephysics about temperature and how it hot/cold it feels. It covers some basics of thermodynamics which will help explain the vid above.

[@TheHuesSciTech]

It may seem unintuitive, but that's exactly what happens. 0 degrees C ice + salt --> -20 degrees C salty water. Where does the "magic coldness" come from? It turns out that you don't just need to get water to 0 degrees C to make it freeze. You need to take out the latent heat of fusion of water, so 0 degrees C ice has a lot less thermal energy in it than 0 degrees C water. That's why ice doesn't instantaneously turn to water when it warms up, the cube hang around for a long time.

[@ChunderThunder1]

It didn't make it colder, it just turned it into a liquid and allowed it to transfer heat a lot easier, due to there no longer being pockets of air. The ice was that temperature all along, the thermometer only said -2 degrees at the start because the air stopped it from getting an accurate reading.

[@nielsosdebbaut]

The question that he should had answered is,why the temperature of the molten ice is colder then when it was frozen. Since you didn't extracted any heat from it. The temperature still dropped. Is it because that it takes energy to go from a solid into a liquid? but only because of that, a drop of 20 degrees seems a lot.

[@Muhovc]

Why do you have milk inside a washing detergent bottle?

[@Muhovc]

I agreed to have been mistaken about this in the previous comments. It does not need to be mentioned in a basic explanation since it's impact is smaller than the ice to water (and it's also the opposite). Our conversation made me want to do an experiment - mix ice with Antifreeze solution for the car

[@Aline_Studio]

Hello head squeeze! Why does teeth get white when you brush them?

[@TheHuesSciTech]

Cheers, but there's no mention of freezing point depression, or latent heat of fusion there.

[@dplocksmith91]

no agar thickener?

[@YarshNBDP]

I remember doing this in my 8th grade science class, good times

[@xBris]

5 Minutes isn't quite what I'd call "instant" but nice trick anyways ;) And congrats to the quarter million!

[@coleslaw1107]

The thing is that in Britain we use °C when something's cold and °F when its hot

[@getrippednubz]

We did this in honors chem last year as our final lab

[@TheFirstInterceptor]

250000 subscribers and their video's aren't watched that much o.O nice job james and co :p I am still watching since the beginning.

[@fredd218]

What happens if you use 1% or 2% milk?

[@TheHuesSciTech]

(1/2) Heat capacity doesn't work that way. Suppose you have a 1kg block of ice in a pot at 0K, and put energy into it. Draw a graph with energy added on the x axis, temperature on the Y axis. It'll go up until it reach 0°C, and then stay there as the ice melts. Then it'll go up again. Specific heat capacity is the gradient of that curve, which is a function of temperature and state (and material). Latent heat of fusion is the amount of energy spent stuck at 0°C. Hopefully you can see that...

[@rudrabows]

Why salt make the ice colder?

[@TheeDrunkunMunky]

I was saying a rough temerature but if you wanna get technical the triple point of water is 0.01°C

[@Muhovc]

1. Ice at -2°C is a very warm ice. And from the video it looks like it wasn't melting yet, so the temperature is very unplausable. 2. Salty water has a smaller heat capacity. Which means it heats up faster than a non-salty water. Since the energy and mass in the bag are constant and the mass and energy of salt are small and W=m*C*T and C of water is 30% bigger than C of salty water --> The salty water now needs more energy to maintain the temperature and it takes it from the "ice cream".

[@Howlites]

We did this at school once :D we had cocoa powder in afterwards :3

[@dommycool100]

i must try this!!!!!!!!!

[@Chasn555]

That is so cool

[@UltimatePwnageNL]

so actually the ice already was -20c but you only measured -2 because it was conducting poorly. right? so when you added the salt it started conducting much better because of it's liquid form.

[@HailAzeez]

Nice

[@TheHuesSciTech]

1. I concede that perhaps you're right, but it's not important. Even *if* the ice was -0.01°C to start with, you'd still get -20°C salty water/ice slush after adding the salt. 2. I'm not sure I follow your point here. The salty water will be maintained at -20°C as long as there's still ice and enough salt there. The heat capacity of the salty water is therefore unimportant if its temperature is constant. Its only role is as 1. a heat conductor from the icecream and 2. a product of the solution).

[@chronousnemesis]

I knew and then made this when I watch some science show hosted by Neil Buchanan. Instead of plastic I used bowl to do it

[@UpsideDownMon]

congrats head squeeze

[@JamezOsborne]

I made it

[@Cinnamon-Pancake97]

Trying it

[@StuartMarchetti]

Same thing my grandfather has been doing for years, except he uses an electric motor, gallon size container, and leaves the janky Ziploc bags at the store.

[@Muhovc]

So, let's say the Ice has the energy of 1 and temperature of 270K (-3°C). Adding salt and mixing it decreases it's freezing point a bit thus speeding up the change of state. If all the ice in the bag were to change into water (ignoring others factors), then since the ratio of heat capacity of ice vs water is 1:2, the temperature would drop to 135K (-138°C). Including the factor of Salty water vs Water 7:10, the temperature of Ice would be 192°C (-80°C).

[@EcceJack]

Well, fridge wouldn't really work. If you meant freezer, it's mainly because if you just put it in like that, it would be surrounded by a lot of air, which conducts heat very poorly, so it would take a lot longer to freeze. This is almost exactly the same reason as why a beer bottle wrapped in damp kitchen towel(s) and put in a freezer for a few minutes cools down much more quickly than without the damp kitchen towel.

[@267MD267]

Cool

[@SnownelVEVO]

Now I just need vanilla... ... and sugar, and milk... ... maybe I should just go buy some ice cream.

[@TheHuesSciTech]

No, ice at 0 degrees C has *much* less energy than water at 0 degrees C. 105 Joules to cool 1g of room temperature water to 0 degrees, a further *334* Joules to freeze it to 0 degrees ice. Salt water has a lower melting point than water, around -20 degrees C apparently. That means that when you add the salt, one of two things can happen: a) it all melts to salt water b) it becomes salt/ice mixture at -20 degrees C. There isn't nearly enough energy around to achieve (a), so only (b) can happen.

[@kleankilz201]

250000 people are gonna make this some time this month :D

[@Muhovc]

This creates a huge temperature potential between the ice bag and milk thus the flow of heat from milk to ice is very big - so milk freezes faster. This flow also increases the temperature of the 'salty water ice" by a bit. I just proved, that you are correct. Well played. I still disagree with the starting temperature of ICE (but just by commons sence) and with his measuring method (first measuring ice, later measuring ice cream). Thermal balance has not been established yet.

[@andrewndavis]

I did this with liquid nitrogen and it tasted awsome

[@ronmaest]

Spending $1 gets me more ice cream and alot faster at that!

[@RoloFilms]

Not really instant, but still pretty cool! :D

[@TheHuesSciTech]

So because your explanation makes no mention of the latent heat of ice, I'm wondering why your explanation doesn't also apply to the addition salt to plain, liquid water. Are you saying that adding salt to 0.01°C water would cause it to cool down to -20°C (or -19°C)? If not, where does the fact that we're starting with ice factor specifically into your explanation?

[@TheHuesSciTech]

(2/2) ...taking the gradients (heat capacities) before and after melting and taking their ratio isn't at all meaningful. In particular, temp * heat capacity != energy, so is not conserved -- none of this ratio stuff makes sense -- but what you can do is look at two points on the curve and ask "how much energy is released/absorbed if I move from A to B?" In this particular reaction, because we're staying pretty close to 0°C, the latent heat of fusion really dominates proceedings.

[@gimpdoctor8362]

this is like ice cream for icecreamjunkies

[@TheHuesSciTech]

Also, a touch of history: back before the invention of refrigeration, they'd get chunks of glacier/ice from up north, and ship it back to warmer climates. They keep it in well-insulated rooms, but it's absurd to claim that the ice was actually colder than 0 degrees C when its surface was constantly, slowly melting. Maybe the centre of an ice cube can hold -20 degrees C from when it was in the freezer 5 minutes ago, but not here. Then ppl would add salt, and make ice cream that way. Explain?

[@MitchDenham]

Would this work on a larger scale? Say, 10x larger?

[@beckjones2665]

red top in america. and the point is that you can make it at home. i cant get liquid nitrogen

[@TheHuesSciTech]

(3/2) I must admit that I am fairly deliberately sidestepping the question of exactly what the correct way of factoring in the different heat capacity of salt water vs water is. But I am nevertheless completely sure that it has no important role in the basic explanation of this phenomenon. (It would be important in doing precise calculation of exactly how much ice melted, etc.)

[@dommycool100]

how exciting! -_-

[@Muhovc]

Hmm..I checked, and the difference of heat capacity of ice vs water is 2:1. So this is the dominant reason - the change of the state of water. (adding salt to 0.01°C water will increase it's temperature a bit, but more importantly, lower it's freezing point so my previous post is just the opposite). So if you find&replace the words from my previous points: Water to Ice and Salty water to Water, my claim then holds.

[@hiddensquid42069]

just use dry-ice. It way colder and it just evaporates out the ice cream.

[@Muhovc]

He's measuring the temperature of the ice-cream in the end, not ice. The reason why ice cream has -20°C is because the water around it changed it's heat capacity (added salt) and because of this it ice has to: 1: "steal" surrounding energy to maintain it's temperature (make ice cream colder). or 2: "drop its own temperature". Both things happen. Since the change of heat capacity is only 30%, temperature drop of ice is 30% at best (but is likely less or it even rose due to energy from milk)

[@christianmoriarty2668]

damn now i want ice cream

[@tkbadgirl]

I gotta go get some ice. ^_^

[@k421838]

he didnt show his ice cream in a bowl .. wonder if it looked any good?

[@predator412569]

where i live there are no caps 0.o

[@SEThatered]

It doesn't. It just speeds up the heat transfer rates.

[@samuelaplin4808]

Not quite instant, But awesome never less.

[@bocefusboy]

Lol in America the label for whole is red, not blue.

[@VOLKAERIN]

Dude. That was easy.

[@wh0586]

hmm, what is easier and cheaper to get a hold of if you live in certain areas of the world, a whole load of liquid nitrogen or salt and ice..

[@hiddensquid42069]

Just use dry ice. It way colder and it just evaporates out the ice cream.

[@cheekyspoon9085]

In England we don't have 2%. Its full,semi or low fat.

[@rohinmukherjee5280]

I made ice cream in one minute. I started by opening my freezer.

[@TheHuesSciTech]

Jon was measuring the temperature using a thermometer, not a human hand. The thermometer does indeed need to equilibrate with the ice, yes, but when he took the reading, it was a solid, steady -1 degrees C, not asymptotically travelling to a different temperature. Having water to conduct heat out of the ice cream is a bonus, but not the critical phenomenon here. And again, there's no contradiction here. -1, or 0 degrees C ice, mixed with salt, yields -20 degrees C salty slushy ice. No problems.

[@SEThatered]

You cannot make "an ice colder" without the use of a fridge. Salt is merely lowering the melting point, but it is not an endothermic reaction by any means. Just pour some salt in a room temperature water and see if it got any colder, genius.

[@roanballeur6079]

How do you mean 90% of the subscriber, would that be me eating a cone of ice cream whilst missing half of my left arm?

[@wowwar2]

who makes ice cream in what looks like an abandoned warehouse

[@googleboughtmee]

I watched all that and they didn't actually show the result

[@Tacobellmotel]

Something I've seen before, but it's cool nonetheless.

[@pugman205]

its an LDV Convoy van with a shed load of paintballs having been fired at it.

[@Muhovc]

Video is still wrong though. It sais the temperature of Ice went from -2 to -20 and the temperature of milk went from about 10 to -20. What he's saying is that the energy of the system somehow wanished. And that can not hapen. Energy from milk got sucked in to ice - thus warming up the ice. Please do reply and correct me, this is getting interesting.

[@makaylad13]

We made this in 6th grade at school! :D

[@itsiggythemaster2633]

Same here its so delicious