Liquid/Steam

[Christine Honda 2I]

Can someone explain to me why steam causes worse burns than boiling water? I know he went over it in great detail during lecture but I want to be sure that I have the concepts solidified.

[Rory Simpson 2F]

Basically, during phase changes the temperature of a substance remains constant despite increasing amounts of energy (he showed us that phase diagram in lecture.) So, water at 100 degrees Celsius has much less energy in it than water vapor at 100 degrees Celsius because the vapor has additional energy due to the phase change.

[Sukanya Mohapatra 2G]

When steam comes into contact with skin, it condenses since the skin is at a lower temperature. The process of condensation releases energy (as heat) which causes the burn. Since the water is going through a phase change, the temperature of the steam is not getting lower even though energy is being released. This process along with the large amount of heat that it releases, is what makes steam burns so severe.

[Sydney Pell 2E]

When water is boiled to 100 degrees C, some of it is converted to steam. Water as steam has more energy than liquid water because it requires additional energy as enthalpy of vaporization as it turns to gas. So, steam at 100 degrees Celsius has the energy of water at 100 degrees C plus the enthalpy of vaporization. Its higher energy means it will cause more severe burns.