Which one is hotter.

[TeleHoar]

sorry...not about models.

Which is Hotter?
Boiling water (212 degrees at sea level)
Steam (Also 212 degrees at sea level)
How can they both be 212 degrees?


I do know the answer...discuss away.

[BigAirSkier1580]

Steam is nothing but smaller liquid water particles. But within steam can be "invisible" elements >212. Therefore steam can be "hotter".

Am I even close?

[Brock Landers]

Steam is hotter.

[The Dad]

By definition, boiling water is water at or about the boiling point, while steam is water that has exceeded the boiling point. It's a different phase of matter.

Unless I'm missing something, this is like asking which is hotter, (a) ice or (b) cold water.

[Steven S. Dallas]

Melissa Therieau.

[Sensisnow]

Here is why I think the water is hotter:

The boiling water is receiving heat which will keep it at 212 as long as the source of heat remains. However, once the boiling water turns into steam it meets with the cooler air rapidly dropping it's temperature back below 212 degrees.

[13]

simple answer: steam is hotter -- it loses its heat much quicker than liquid water.

Steam is nothing but smaller liquid water particles. But within steam can be "invisible" elements >212. Therefore steam can be "hotter".

Am I even close?

not quite. water molecules don't lose mass when they go from liquid to gaseous state.

steam is simply water with higher kinetic energy than liquid water. no mass is gained or lost in the change from one phase to another. if it did lose mass, it would no longer be H20.

[WWCD]

Temperature is a unit of measurement. They are the same.

It's like asking, "Which is heavier, a lbs of rocks or a lbs of feathers?"

[Steven S. Dallas]

Fo real-

the steam is hotter because it contains more thermal energy. It takes more energy to turn the water into steam than it does simply to bring the water to a boil. The thermal energy produced during the conversion of water to steam remains in the steam, so it is "hotter."

I'm probably wrong, though, I only remember that from conceptual physics in 9th grade. Or was it home ec?

[RootSkier]

Fo real-

Good thing you stick with the more liberal arts.

[Beaver]

Steam can happen at very low temperatures, as can boiling. Water in a vaccum boils at a low temp (I have no idea how low but I recall in school we boiled water at room temp by subjecting it to a partial vaccum.) Steam happens on the river when it is cold out and the water is warmer than the air.

So basically, your question needs work.

[Yeti]

Telehoar did state that the steam and water were both at 212 degrees at 0ASL. Never mind that steam can be at a higher temperature than 212 degrees -- of course that would be hotter, but let's assume that T-hoar means what he says.

My guess is that T-hoar is looking for a discussion of which one can deliver more heat to a given target -- whether scalding your hand or (more usefully) heating an object for industrial purposes. The relevant analysis for that should be which of steam/water packs more deliverable heat...

[Steven S. Dallas]

Good thing you stick with the more liberal arts.

Damn it!

[WWCD]

Define Hotter.

[Steven S. Dallas]

Define Hotter.

Melissa Therieau.

[WWCD]

Melissa Therieau.

I guess you were right the first time.

[babel]

Assuming a closed system the water will remain at 212 as the water changes phase to steam. The water and the steam will stay at the same temp until all water has changed to steam, then steam will gain temp again. So the answer is either they are the same temp or steam is hotter (assuming you keep heating it)
edit: The reason they can be the same temp is that the energy that changes the water to steam is used up in the phase change and therefore doesn't increase the temp of the steam.

[Evmo]

I was always taught that steam changing back in to liquid was an exothermic reaction, and therefore steam harms you more (delivers more heat) than liquid boiling water... AKA, if one had the choice, supposedly it is better to put your hand in boiling water than to put it in steam of same temp... But what do i know...

[Conundrum]

Melissa Therieau.

Yep

Temperature is a unit of measurement. They are the same.

It's like asking, "Which is heavier, a lbs of rocks or a lbs of feathers?"

Yep

They can both be 212 because you told us they were and this is the padded room so anything goes.

Boiling water by defintion is water at the point of converting from liquid to gas. Steam can exist at a lot of temperatures. The "steam" you see above boiling water is actually tiny groups of water molecules that have cooled once hitting air temp that is cooler than 212. If the air temp was above 212, you would not see steam above boiling water. Water in a gaseous state is invisible.

If you are talking about a pot of water on a stove, the boiling water is 212, the gaseous water is 212, and the steam that you can see is now condensing in liquid form because it is dropping in temperature and should be cooler than the boiling water because it's energy has already been lost however that gaseous water you don't see will burn the shit out of you.

[Beaver]

Assuming a closed system the water will remain at 212 as the water changes phase to steam. The water and the steam will stay at the same temp until all water has changed to steam, then steam will gain temp again. So the answer is either they are the same temp or steam is hotter (assuming you keep heating it)
edit: The reason they can be the same temp is that the energy that changes the water to steam is used up in the phase change and therefore doesn't increase the temp of the steam.

That closed system will asplode because the pressure will become too great to remain contained.

[ak_powder_monkey]

steam is hotter because it can become hotter than boiling water just like ice can be colder than 32

[runethechamp]

They have the same temperature but different energy levels. The energy level is ultimately what defines your perception of "heat", and what it can do to you. For instance, 120 degree air is just hot to be in, but you can take it for a long time. 120 degree water will burn the shit out of you.

And AKPM, he already said it's at the same temperature.

[Mountain Junkie]

Oh crap, here we go again.

Airplane on a treadmill, round 2.

[TeleHoar]

Ha...
Some great answers.

I was looking for the magic "BTU" word

Steam and boiling water are the same temperature. (Steam can be superheated -true)

But steam has changed state requiring the addition of an exponential amount of BTU's to change the water to steam.

Steam contains a buttload more BTUs than boiling water and would be considered hotter.

Buttload is indeed a scientific word.

carry on

[Steven S. Dallas]

Steam contains a buttload more BTUs than boiling water and would be considered hotter.

Isn't that what I said (BTU being the measure of thermal energy)?

No, probably not.