What Are The Small Bubbles In Boiling Water Made Of?

It's steam....

http://cr4.globalspec.com/search/sitesearch?do=show&order=asc&sort=textmatchrank&srch=Bubbles%20In%20Boiling%20Water

Dihydrogen monoxide. Obviously.

It's steam. Sorry!

Water expands roughly 1,600 times in volume when it turns to steam.

That's what the tiny bubbles are, that's what the little bubbles are and that's what the big bubbles are.

The temperature gradient in the water isn't that much. Remember as water heats up it expands and rises, pushing the cooler water down to be heated, so the water is circulating and so is the heat.

There are probably You Tube demos. Do a search.

It is clear to see that you do not have the patience to closely study a glass pot of water from the time it's cold to the time it is rapid boiling. I didn't ask the question because I missed the day in second grade when they described how water boils! I asked the question because I studied the boiling process in depth for many hours over the period of many years and realized that there are distinct differences in the bubbles that occur long before the boiling temp is reached. "Boiling water" is an arbitrary term anyway - if the entire pot were at boiling temperature, simultaneously - your house would be flying into tiny bits from the sudden explosion of steam. a pot of boiling water ..... is NOT ever entirely at boiling temperature. Please don't be condescending when you, yourself, have not done the research. Haroldoftroy

It can only be steam or dissolved gases coming out of solution. Have you tried it with water previously boiled to expel air? Any differences should give an indication. BTW gas boiled out of water has composition different from air e.g. higher in oxygen as solubilities at given partial pressure are different.

Its small and big bubbles made of steam. If you was in charge of the filling you know there is only water in there. If in doubt try distilled water.

Almost nothing can spoil that experiment.

I believe you are correct. It is dissolved gasses in the water that form the small bubbles prior to reaching a full boil.

It is technically called nucleate boiling and the tiny bubbles forms on the defects on the surface of the container. Same principle when opening a soda bottle and CO₂ bubbles suddenly form on the inside of the bottle.

No, nucleate boiling is still the formation of steam bubbles in water. It does happen at very localized hot spots.

Thanks for the correction. Pulling that stuff out of old memory and I guess some neuronal pathways have become crossed.

Oh boy! Now I can call my teapot a "nucleate reactor" and scare people. For hicks, that would be a "nuculate reactor.

Nuculur if you're from Arkansas.

Since the OP did not mention the nature or intensity of his heat source, nor any pressure on this system, I shall add to the discussion of dissolved light solutes (gases) "boiling" out of solution, first by stating if you have a solution of sodium bicarbonate in degassed water (start under good vacuum), and vigorously heat with a high temperature source very rapidly, then the dissolved salt in this case will disproportionate to carbon dioxide ("boils" out of solution), and sodium carbonate.

There are a number of thermally labile compounds called pyrolytic salts (as ammonium bicarbonate example) that "boil" out of solution well below the normal boiling point of water. One cannot "observe" a system and make conclusions about it without a proper definition of the system. So, Mr. OP, please do go ahead and define the system.

Did you know that water with a colloidal suspension of carbon or gold nanopaticles in it will boil and exert steam pressure when concentration sunlight is present, even though bulk water temperature is no where near the boiling point?

He said, "what time is it".

We tell him how to build a watch!

Come on, let's not beat this into the ground.

Yep, but the OP didn't want to hear that the bubbles are just steam.

My question is; "What are all of the small and large bubbles in a hot tub?"

They're very friendly bubbles.

There is a legend about how Walla Walla, WA, USA was named....

Sorry but I couldn't think of a short "Jeopardy " answer in the form of a question.

Better answer by far.

Hopefully the OP gets as much out of this as I have.

Thanks!

Water boils in several stages, too.

Must be some really good stuff your smoking to have the patience to sit there and analyze and wonder about all those bubbles. I wonder what they use on the "Lawrence Welk's Show"? They were big bubbles too but I don't think they were steam.

But then I never did like that show, and didn't have any of the good $hit back then,to give me the patience, and so I couldn't sit there and analyze them

Steam(water vapor) is invisible to the naked eye.

What you call steam is really condensed water vapor.

The bubbles are water vapor or entrained gases.

The initial bubbles when water is heated is nominally:

Nitrogen -- N₂ -- 78.084%, Oxygen -- O₂ -- 20.9476%, Argon -- Ar -- 0.934%, Carbon Dioxide -- CO₂ -- 0.0314%, Neon -- Ne -- 0.001818%, Methane -- CH₄ -- 0.0002%, Helium -- He -- 0.000524%, Krypton -- Kr -- 0.000114%, Hydrogen -- H₂ -- 0.00005%, Xenon -- Xe -- 0.0000087% (Air that was dissolved in the water)

When it starts to approach the boiling point, the bubbles that rise are: the vapor phase of Dihydrogen monoxide (oxidane). There are also trace amounts of deuterium monoxide in the liquid. This is plain old ordinary water.

Ice cubes are the solidified state of the above.

Good Luck, Old Salt

You seem to have a penchant for observation versus theory. Why don't you try observing pure water - distilled, filtered - in a clean container and see what happens?