Steam vs water at the same temperature

In summary, at standard atmospheric pressure, usually accepted as 14.7 psi, at 100 deg C. water boils and steam condenses simultaneously, 100 C is the max temperature water can reach at this pressure and it is the minimum temperature that steam can exist at this pressure. Therefore it is possible for steam to exist at many times the max temperature of water.
  • #1
daveed
138
0
if steam and water are both at 100 degrees celsius, why would the steam scald you more, even if they both have the same kinetic energy?
 
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  • #2
Do you mean steam as in evaporized water? :confused: Because I don' think it's possible to have water and water vapor at the same temperature. Heat is energy and would give water vapor a stronger energy than room temp. water. Making it more likely to scald you. Heat is needed to evaporate water.

I think that's what you were asking.
 
  • #3
Oh ya, I'm pretty sure, the more kinetic energy the more heat it emits. (Kinetic Energy of molecule i.e H20, having more motion, therefore more kinectic energy)
 
  • #4
daveed said:
if steam and water are both at 100 degrees celsius, why would the steam scald you more, even if they both have the same kinetic energy?
Steam has more energy than water because it takes energy to break the bonds that keep it a liquid. When steam hits you, some of it condenses, and your skin absorbs all that extra energy.
 
  • #5
DB said:
Because I don' think it's possible to have water and water vapor at the same temperature.

That's false, you can have a mixture of steam and water (vapor) at the same temperature, just the temperature of change of state.

russ_watters said:
Steam has more energy than water because it takes energy to break the bonds that keep it a liquid. When steam hits you, some of it condenses, and your skin absorbs all that extra energy.

That's a good explanation. It sounds good.
 
  • #6
is it called superheated?
 
  • #7
No. It's superheated once there is no longer a dryness fraction (ie once all the liquid water in the mixture has evaporated, or when the steam is 'dry'.). This is the region beyond the saturation line on a Ts diagram of water boiling.
 
  • #8
Once water reached it's evaporation point, it changes into steam, and floats away into the air. This small amount of water reduces the overall temperature of water to 212 degrees F. This means no matter what water's temperature will not exceed 212 degrees F. For example, if you put a cup of water in an oven at 400 degrees F, the water would be 212 degrees F. Why? Because as, water heats to it's evaporation point, (212) it turns to steam. Steam is less dense than air, so it rises away from the cup. This reduces the overall temperature of the water, making it stay at a temperature of 212 degrees F or 100 C.
 
  • #9
Dual Op Amp said:
This means no matter what water's temperature will not exceed 212 degrees F.

This is not true. Water could easily exceed this temperature, if the pressure was allowed to rise above atmospheric. For example, at 4.7atm, the boiling point of water is roughly 150 degrees Celcius.
 
  • #10
This is misleading at best:
Dual Op Amp said:
Once water reached it's evaporation point, it changes into steam, and floats away into the air.
When a specific mass of water reaches 100C, it isn't even close to having enough energy for all of it to turn to steam. It takes 539 cal/gram to boil water that is already at its boiling point, but to raise it one degree C (to get to the boiling point) only takes 1 cal/gram.
 
  • #11
daveed said:
if steam and water are both at 100 degrees celsius, why would the steam scald you more, even if they both have the same kinetic energy?

At standard atmospheric pressure, usually accepted as 14.7 psi, at 100 deg C. water boils and steam condenses simultaneously, 100 C is the max temperature water can reach at this pressure and it is the minimum temperature that steam can exist at this pressure. Therefore it is possible for steam to exist at many times the max temperature of water.
 
  • #12


the owen is a constant heating device, water upon constant heating beyond the Tsat will yield to super-heated tendencies, meaning the cup becomes empty & the owen is filled with steam at super-heated temperatures and the pressure rises. The Latent heat of vapourization is surpassed by constant heating easily..
 
  • #13


Nov21-04, 03:12 PM <---Whew! Long time ago that this thread was brought up for air!
 
  • #14


Indeed. And it seems gibberish to me.

What's an owen?
 
  • #15


Probably an oven.
 
  • #16


sorry. its oven, my bad..
 
  • #17


Ok, but I still don't get how your post is shedding any light on the topic.

I guess it doesn't matter; the thread's 7 years old.
 
  • #18


just a random browse n got into it..didnt get to see when were these published in the forum..
 

What is the difference between steam and water at the same temperature?

Steam and water at the same temperature are both forms of water, but they have different physical properties. Steam is the gaseous form of water, while water is the liquid form. Steam is created when water is heated to its boiling point and evaporates. Water, on the other hand, remains in its liquid state at the same temperature.

Does steam and water at the same temperature have the same energy content?

No, steam and water at the same temperature do not have the same energy content. Steam has a higher energy content because it requires more energy to convert water into steam. This process is known as the latent heat of vaporization. Therefore, even though steam and water may be at the same temperature, steam has more energy stored within it.

Which is more dangerous, steam or water at the same temperature?

Both steam and water at the same temperature can be dangerous in their own ways. Steam can cause burns and scalding due to its high temperature, while water can cause drowning or hypothermia if it is too cold. However, in terms of heat transfer, steam is more dangerous as it has a higher heat capacity and can transfer heat more quickly than water.

Can steam and water at the same temperature coexist?

Yes, steam and water at the same temperature can coexist under certain conditions. This is known as saturation or equilibrium. At this point, the rate of water molecules evaporating and steam molecules condensing is equal, resulting in a balance between the two forms of water. However, any change in temperature or pressure can disrupt this equilibrium.

What happens when steam and water at the same temperature are mixed?

When steam and water at the same temperature are mixed, they will reach a new equilibrium state. Some steam will condense into water, while some water will evaporate into steam until the new equilibrium is reached. This process is known as condensation or evaporation, depending on the direction of the change in state. The resulting mixture will have a temperature lower than the initial temperature of the steam, but higher than the initial temperature of the water.

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