Boiling Water in Less Than 30 Seconds? - Vapor Pressure Experiment

[inventorr77]

MrCensorman: Yes you are correct. There is a point of 'equilibrium' where the air will stop being released from the water based on the vacuum level. Up to a point, as the vacuum pressure is increased more air will be removed.

[MrCensorman]

i think it gets to a certain point where it take the air out of the water am i correct?

[DonMecanico]

why are vacuums measured in "inches of Mercury" i cant find the answer anywhere. Impressing video, thank you.

[inventorr77]

@DonMecanico Please search a bit harder and you will surely find the answer you are looking for. You can start by searching for wikipedia and Vacuum mercury

[monsi23]

got a question, can u isolate a vacuum pressure, for instance u pump out air and simply close the valve, will the vacuum stay there for ever?

regards

[josephdupont]

So dry your cloths with this! or your vegetables.

[mongooseman897]

wow its not boiling the negative presure is causing it to bubbel change the vaccume o a pump to apply pressure and the water will compress into a slid NOT ICE a solid form of water ( if the glass doesnt shatter ) you my friend are an idiot

[g4m3r43v3r]

So applying very high pressure on water will turn it in to ice?

[AdminOnDuty]

@g4m3r43v3r

Regarding turning water to ice with pressure, research "Ice X Lattice" (which is Ice Ten with roman numeral) ;-)

[MrTerryKay]

Is there a way of harnessing this idea to make an energy efficient cuppa?

[tangnatalaga]

Actually the vapor should be very cold because when a substance change for liquid to gas, a lot of heat isbeing removed which is how refrigeration works. If you use only very little water in the jar you would have produced refrigeration.

[ItsRyanStudios]

is that that cool vacuum pump you connect to your faucet?

thanks

[airsoftmaniac911]

no u make it bubble not boil

[aucorr]

what is he law of this experiment?

[joshualaprade]

The boiling point of water at 29.5" (atmospheric

pressure at sea-level) is 100 degC. Reducing the pressure down to

28" will minimally change the boiling point of the water to

approximately 99 degC. Thus, unless you happen to be heating the

water to this temperature, the water is not really boiling. If you performed this same experiment with only a few inches of water in the jar at the same pressure, you would see jack happen.

[joshualaprade]

Thats out-gasing is it not? The boiling bubbles are a lot smaller and out-gasing occurs first until all the gas is released. I would be curious to see if later in the video the large bubbling stops and the vacuum needs to be increased to attain the same result with much smaller bubbles.

And no food cannot be prepared this way because the reason for boiling is to bring the temperature above 170F to kill bacteria and parasites.

[hyunseob900]

Are certain foods prepared this way?

[gopsr69]

If water boils in vacuum is that why there is no water in space , because there is vacuum and all of it vapourised ?

[zippity739]

its not really boiling the atoms are jumping

[soccom8341576]

It's probably a better way to make distilled water.

[00011theman]

well im dont sure but idk if u can cook food with it

[brainjammed]

I can't see why you wouldn't be able to degas silicone with this set up. I'm not sure why it isn't a very popular method considering the hight cost of degassing vacuum pumps. You only need 28 inches Hg to degas silicone and this creates a stronger vacuum than that.

[spagboll616]

thanx

[brainjammed]

I tried it. It works really well. I ordered a aspirator like in this video from EBay, an adapter for the faucet and some 3/8" internal diameter braided Vinyl hose from Home Depot and last but not least " Food Saver " brand Canisters you can buy from a Kitchen department (pack of 3 sizes). The hose fits very well at both ends so that's all you need. You can do the second mix of the silicone/catalyst directly in the canister as unused peels out later. It REALLY expands so go >3 times the size

[brainjammed]

The canisters have a one way valve so it will hold the pressure until you press a button at the top. There's a cap on the inside of the lid that may pop off if you let the air back in too quickly so either let the air in slowly or remove the cap before degassing. I used the outdoor faucet as it has the best flow - I measured 29"

[spagboll616]

@brainjammed; thanx for the help, but for the life of me i cant find a site that will deliver them to the uk. looks like i'll have to do it this way and pray i dont blow myself up. you think the seal will hold if i hot glue or super glue around it? thanx agen

[brainjammed]

@spagboll616

29inches of mercury is the equivalent of about 14 psi so not a huge pressure difference compared to what you could create with an air compressor. I wouldn't worry about how you seal it too much - chewing gum would work if you were in a pinch.

[spagboll616]

can anyone help me? i need to degas sillicone at 29". could i use this method to get the majority of the air out? any help would be great thanx

[toddmelliott]

I have used this method to degas silicone. The amount of vacuum that you can achieve depends on your water pressure though. In my apartment, it fluctuates, so sometimes I can get 30" and other times I can only get 28.5".

[ihavestage4coolness]

would the pressure cook food? cook food at 70 degrees? Would the bacterium survive?

[soccom8341576]

It's not going to cook well at 70 degrees.

[spagboll616]

did it work well?

[Cheddabob135]

43 seconds

[inventorr77]

Yes. Yes. I suppose I can change the title to "Boiling water in less than 43 Seconds?" :-)

[Cheddabob135]

lol

[mb0185646]

@inventorr77

It would have to be less than or equal to 43 seconds. Or less than 44 seconds.....

[AdminOnDuty]

@inventorr77

Also, I think the gauge reads 27.5 rather than 28.5 - But thank you very much for the demonstration!

[mdlman583]

You are removing excess oxygen,not boiling it.

[EinkOLED]

It is the removal of pressure or the resistance of the molecules to move which allows it to boil, not the removal of oxygen.

Okay, you are removing the oxygen and sea-level pressure acting around the bottle, but the oxygen within the water still remains.

If you remove oxygen from water then you get hydrogen.

Pressure acts like a resistance, the higher the pressure the lower the resistance to move.

[littlefatzrow]

Yes he is boiling it! A boiling liquid is always a PRODUCT of a TEMPERATURE / PRESSURE RELATIONSHIP. Water will not boil until a higher temp under pressure just like a car radiator. Lakes of liquid nitrogen exist on the moons around the outer planets because of their low temp. Superheated water (same principle as a pressure canner or Bunn coffee maker) exists at volcanic vents on the ocean floor and is known to be around 2,000 deg F and does NOT boil because of the extreme pressure.

[clnmyjts]

just because it boiling don`t mean it hot...LOL that still cool thanks

[d0mp1zzl3]

it's a nice experiment, but what use is boiling water @ ~ 22 °C ...

[mattyremf]

i designed a machine with my uncle which involved a vucuum being placed on a product to dry it much faster.

[derkozten]

Good question... what was the atmospheric pressure in this day? The regular 101.325 kPa or something different?

And this experiment is explained by the TP phase diagram. This diagram shows the relationship between the saturation (boiling) pressure and the corresponding saturation temperature. The corollary is: the lower the pressure, the lower the temperature, but in a different way from Gay-Lussac's equation.

[benjoeuk2006]

Yes thats true for gases. But If you shake a coke bottle, you build up pressure in the tiny air space above it, open the top and the pressure decreases. This causes the co2 in the water to be releases, it doesnt boil does it? He can put his hand on it. It's the gases becoming less soluble. It's how divers get the bends, etc.

[derkozten]

TP diagrams are true for ALL pure substances, like water in this case. It doesn't matter if it's solid, liquid or gas at standart conditions

The CO2 release from a coke bottle obeys a similar but different principle: the Henry's Law. It says that the solubility of a gas inside a liquid (it's "liquid concentration") is directly proportional to the pressure exerted from the gas phase above that liquid solution.

[blower05]

BOILING should get some water droplets condensed from vapour on the wall of the bottle. Did you find this? If not, I think this should be cavitation due to low enough pressure to water.

[chrataxe]

Boiling doesn't neccessarily mean droplets will form on the bottle. Condensation on the glass means the vapor pressure is GREATER than the atmospheric pressure, meaning the vacuum can't suck out the water vapor faster than the water releases it. If condensation does not form, that means vapor and atmospheric pressure are equal, which means the rate at which the vacuum sucks out the gas is equal to the rate at which water releases gas

[benjoeuk2006]

I'll explain the physics for you. When the volume is constant, Pressure/Temperature = constant, therefore P1/T1 = P2/T2 (P1 is the pressure before P2 is new pressure, same applies for temperature). So in simple maths. If the pressure is orignally 10 and the temperature is 1 the constant = 10. So if the pressure now becomes 5. 5/T2 = 10 or 5/10(the constant) = T2 (the new temperature) = 2. So by dropping the pressure, the temperature rises from 1 to 2.

[benjoeuk2006]

However I don't think that a drop in pressure that small can make water boil, you are in fact reducing the solibility of the gases disolved in the water by increasing the pressure.

[rudmop]

You are not applying Gay-Lussac's law correctly. You can't apply a gas law to a liquid. Also the man in the video is not increasing the pressure as you state below, he is reducing the pressure. The solubility of most gases in liquids increases with increased pressure of that gas above the liquid. You have it backwards. See Henry's Law.

[rudmop]

see my comment above benjoeuk200k about this comment

[tonycomitto1]

your a dumb fuck. that is completely wrong! the temp is NOT rising! It is not dissolved gases. The water is boiling because the vapour pressure is lower.

[UndefineDestiny]

my chemistry and physics is horrible. but if p1/v1 = p2/v2

and p1=10, v1=1, constant=10, p2=5, then

10/1 = 5/v2, which ultimately means

(v2)10 = 5, which you can isolate v2 to equal,

v2 = (5/10). last time i checked, 5/10= half.

i believe 1 (the temperature before) is greater than half (the temperature after)...so isnt this a drop in temperature?

and its true about the water evaporating much faster due to lower pressure

[An1MuS]

pV=mRT is for ideal gases only, right?

[danielashtiani]

pv=nrt....

[An1MuS]

v=V/m

n=m/Mr

R=Rslash/m

It's the same thing.. Do your homeworks.

[mellowmaromi1]

Is it really boiling, or just appearing so. Boiling is the transition from liquid to gas. Are you sure this just isn't extracting the air in the water?

[desertdog2008]

In fact the water is boiling. By definition the boiling point of any liquid is the temperature at which its vapor pressure is equal to atmospheric pressure. If atmospheric pressure is lowered, as is done in the video with a vacuum pump, water will boil at a lower temperature - in this case, room temperature.

[mfisker]

He took the air out of that container. Less air pressure means that the water can evaporate at a much smaller temperature.

[hectordrums1981]

hey man I would like to see if you can do a experiment with your boiling water OK try this make it salt water and see if you get flammable gas??????

[crob227]

how fast does it lose its vacuum, if you cut the punp off, and will it mess the machine up?

[mrmrgranite]

The water starts boiling at the point when the vapor pressure of the water at room tempearture equals the pressure in the jar. that is the definition of the boiling point. so yes, the water is boiling, and yes, that is water vapor in the bubbles. what else could it be if all the air was pumped out?

[DrReaper]

You say this is boiling. Is it producing HHO gas? Hydrogen and Oxygen. If so can you collect the gas under vacuum?

[lozanoman]

will this work with distilled water?

[inventorr77]

Yes.  Everyone should know however that no matter what type of liquid you use, after a certain point equilibrium will be reached and the boiling will stop.

[matero10889]

yea...actually, ur supposed to do it with distilled water

[tigerbody69]

Is this boiling or just bubbling from the vaccum?

it's only 72 deg F?

also - to purify, yo need 10 minutes of rolling boil @ 1 atmosphere.

[inventorr77]

Even though the water is only 72 degrees, the bubbling water is correctly considered "boiling" because it is under a vacuum at minus 28 atomospheres of pressure compared to pressure at sea level.

[matero10889]

so, i assume ur not involved in science past the elementary level

...otherwise u wouldnt be talking/typing in terms of degrees Farenheight

[C20rules]

-28 atmospheres - lol

-28,5 inches hg (-96,5 kPa) you mean?

Vapor pressure for water at 22,2°C (72°F) is about 2,6 kPa (0,78 in/hg)

[Drevtoobe]

"-28,5 inches hg"

That must be "free energy" or "antimatter" pressure. lol

Everything was fine until I heard about the "negative" mercury pressure.

[C20rules]

I know it's not the best way to measure - it means 28,5 in/hg (96,51 kPa) below atmospheric pressure

To get absolute pressure you have to take off that from atmospheric pressure but at those low pressures that's not accurate at all as long as you don't have an accurate barometer showing the atmospheric pressure to campare with.

Only small changes in atmospheric pressure caused by example weatherchanges will give huge errors in the calculation of absolute pressure.

[Drevtoobe]

"To get absolute pressure you have to take off that from atmospheric pressure but at those low pressures that's not accurate at all as long as you don't have an accurate barometer showing the atmospheric pressure to campare with."

Exactly. "Subtracting from the top" is a way of describing mercury-equivalent pressure that I have never heard of in my life. Perhaps this clip will be the only time!

[C20rules]

I havn't seen that ether - noramlly you have a barometer showing the absolute pressure.

[C20rules]

also - the gauge shows 27,5 not 28,5 (27,5 in/hg = 93,1 kPa)

[nochitright]

It boils the water but doesn't purify it, correct?

[inventorr77]

Right. It does NOT purify the water because it does not get hot.

[Afr0Thund3r]

So you're saying you can't cook with this? Then can you please explain how this may be useful. This is very interesting.

[spazznout]

The best aplication for this that I have seen is in ethanol stills. Rather than using heat they bring the kettles pressure down and get the same results using less energy as well as no hear for a risk of fire with the ethanol.

See ethanolstilldotcom

[ichooseanother]

Nice demo inventorr77! What exactly are the bubbles made of and why do they occur under vacuum? Why is no heat produced? What did you use to get the --28+Hg? Very interesting stuff, Thanks.

[inventorr77]

These are vapor pressure bubbles. I was able to develop the -28Hg by using a water activated siphon pump as shown in my second video.

Answers to your questions are best explained by searching for vapor pressure bubbles (without quotes) on the web.

[vaultmantk]

neato... I've heard of it happening but have never seen it actually happen. cool