Steam Burning

[Kyra Dingle 1B]

Can someone give again the explanation Lavelle shared last Monday about why steam burns a lot more and how that relates to phase changes?

[Matthew 1C]

Steam burns a lot more than boiling water because more energy is required for phase changes than just temperature changes. With boiling water, the energy that is transferred to the skin will come from the temperature change, but with the steam, a lot of energy will be released onto the skin from the condensation of the steam to water. The energy released onto the skin from steam is the energy that is required firstly for condensation, and then secondly from the energy that comes from the boiling water following condensation.

[Vincent Tse 1K]

Steam "burns" a lot more b/c it typically carries way more energy than boiling water does, and that's due to phase changes, mostly.
You might want to view a water phase diagram as a reference, but here goes:

So liquid water at say, room temp, first needs to heat up to 100 degrees C. It needs X amount of energy to do that.
Once at 100 degrees C, the liquid water is now at its boiling point, and must change to steam. In order to do that, it needs Y amount of energy.
Finally, steam might not actually be exactly 100 degrees C; it might be even hotter than that. To "heat it up" to that temperature, you need to put Z amount of energy in.

So boiling water hurts b/c your skin is getting touched by X amount of energy.
Steam REALLY HURTS b/c your skin is getting roasted by X + Y + Z amount of energy.

[Rachel N 1I]

Steam burns a lot more because the enthalpy of condensation is high. The heating curve for water shows that as water goes through a phase stage into gas, it is dumping a large amount of energy at 100 deg Celsius of heat onto the skin.

[Jesus Rodriguez 1J]

Steam burns more because it is undergoing a phase change as a result of reacting with your skin and the phase change from vapor to liquid causes heat to be released


I found this link to be helpful

http://scienceline.ucsb.edu/getkey.php?key=1322

[Yu Chong 2H]

Steam burns more because it has to first condense into liquid water when it comes to contact with your skin. The heat released from the condensation is added to the heat released from cooling the liquid water from 100 degree to your body temperature. So more heat is released by steam at 100 degrees than water at 100 degrees.

[Cristina Sarmiento 1E]

Steam burns more because of the phase change from liquid to vapor. Water boils at 100 degrees Celsius and during the phase change of vaporization, heat continues to increase. So when the boiling water has been turned into steam, a lot more heat had been supplied and is the reason why steam burns more.

[Ricardo Ruiz Flores 1D]

I would like to add that it's really useful to see the heating curve for water to really understand where all of that extra energy is coming from in the steam version that boiling water does not have.

Conceptually, I like to see it as a pathway the water has to take to reach certain temperatures. For steam to transfer heat with skin, it first has to go through the "phase change" plateau, and in essence "dumps" all of that heat it takes to condense onto skin.

Again, the graph helps visualize this!