They didn't specify this, but it becomes a supercritical fluid

me too... I can finally sleep well now

dont know if you guys gives a damn but if you are bored like me atm you can watch pretty much all the latest series on instaflixxer. Have been streaming with my brother for the last months =)

@Johnathan Jesse yup, been using InstaFlixxer for years myself :D

I came here because of the same confusion...😅😊

Yes, water.

@@MrKnutriis in supercritical water!

So trueeeee....

I bet most of the profs have never seen it with their own eyes.

I agree. Watched a bunch and this one takes the cake.

but it's not a superfluid, it's just CO2

Super heated fluid 🤩

저도 그렇게 생각해요 발젭님

doesn't matter, cause the annomaly is usually between solid and liquid phase.

whats the difference between an anomalous fluid and normal fluid?

@@Hambxne depends on the definition. On this specific case, it means that the molar volume of ice is bigger than water. Usually, in a solid phase the molecules are more tightly bound, therefore, the molar volume is usually smaller for the solid phase, on water, it's the opposite, that's why ice floats on water!

@@MrNabows ahhh okay so its just a fancy way to talk about density after phase changes, awesome! thank you for the concise breakdown!

Mr. N. Anyway the graphic is incorrect , if he is showing critical phase, it has to show has , the graf of a critical CO2 , not from water , big mistake

I believe supercritical is the mixture of gaseous and liquid state. That is the phase boundary where both the states are in physical equilibrium

hey can u pls tell what actually happened AT CRITICAL POINT ?

So at first we had a clear separation between the liquid and vapour. Then when the temp and pressure is raised to the critical point, the boundary between the 2 phases disappear. So, at the critical point the liquid and vapour have the same density and that’s why we can’t distinguish between the vapour and the liquid.

@@mysterywoman8158 thnkuuu

@@preetibhall its okay

I would like the answer

technically it's just a fluid as both gases and liquids are fluids

it will probably boil away

Probably closing the bleeding valve

As it’s shown in the film, it took some trial and error to get the amount of dry ice right in order to get a useful liquid-vapour-mixture to start with. Too little dry ice may result in a pure gas phase already at room temperature and then it turned out to be difficult to observe a phase boundary between liquid and gas phase on the way to the supercritical state. On the other hand, too much dry ice could result in a too quick pressure rise already when the CO2 in the pressure chamber goes to its initial equilibrium state (before the heating plate is turned on). Therefore, it is important to have an automatic pressure relief valve, which opens at a predefined pressure, as one of several safety measures when conducting experiments like this.

Medielab HVL does it need to be trial and error? the remaining critical constant not so much talked about is critical volume (molar volume at T_cr and P_cr), I think if we knew the volume of cylinder and and a relation between volume of solid CO2 and supercritical fluid CO2 for a particular number of moles, then it will be predetermined what amount of dry ice will go into the cylinder. i am just a high school kid, btw, does the remaining volume of cylinder at the start(just after putting dry ice), that's get filled with air, affect the state?

afriso

It is acryl glass with a thickness of 30 mm. They have to be replaced regularly because the material becomes opaque after several runs of the experiment. You also have to be careful when drilling the holes for the bolts. Acryl is a bit brittle and higher drilling speeds may lead to some cracking of the material.

Is there any way to buy the vessel? I mean for educational purposes in such a small scale...

The pressure would rapidly drop, and as a result, the temperature too, causing initially a violent jet of CO2 out of the vessel as it expands, then rapidly forming liquid CO2 droplets and vapour (depending on the room temperature, size of the CO2 chamber, and size of the opening) as it cooled rapidly. It would almost certainly condense moisture in the air rapidly too. The vapour/liquid could also rapidly solidify into dry ice crystals , since the expansion from 70+ bar to 1 bar would likely result in lower than ambient temperatures in the CO2. It would instantly fall below the critical pressure and temperature.

@@onetrickhorsewould it cause a drop in temperature? The highly pressurised gas being released into 1 atm will just expand very quickly out into the surroundings but should stay at the same temperature, and it would just turn into co2 vapour

@@theweirdwolf1877 indeed, so the release of the CO2 from high pressure to low pressure undergoes expansion that relates to Boyle's law, which states that P1*V1 = P2*V2, in other words, as the pressure drops from P1 to P2, the volume increases proportionally. Because the thermal energy in a fixed volume V1 is the same as the thermal energy in the volume V2, the thermal energy is spread over a larger volume, which results in the drop in temperature though expansion for that new volume.