Well it's not as simple as the boiling point, which is of course 100°C / 212°F. (You may assume standard atmospheric pressure.) But you're on the right track to speak of the gas phase. In fact (ANOTHER HINT), it involves both the gas and liquid phases.
Posts: 1896 | Location: U.S. | Registered: 06-03-02
I wasn't actually referring to the boiling point of water, I was referring to the vapor pressure and evaporation properties. I know that isn't right but that was the only thing I could think of.
Posts: 9192 | Location: Atlanta, GA, USA | Registered: 06-03-02
Have you ever sprinkled water onto a really hot griddle and seen it scoot across instead of instantly evaporating? That will happen if the griddle is above the Leidenfrost point - an insulating layer of vapor is produced which keeps the rest of the water from rapidly boiling.
Posts: 7614 | Location: in the backwoods of North Carolina | Registered: 06-07-02
The Leidenfrost effect is a phenomenon in which a liquid, in near contact with a mass significantly hotter than its boiling point, produces an insulating vapor layer which keeps that liquid from boiling rapidly.
This is most commonly seen when cooking; one sprinkles drops of water in a skillet to gauge its temperature—if the skillet's temperature is at or above the Leidenfrost point, the water skitters across the metal and takes longer to evaporate than it would in a skillet that is hot, but at a temperature below the Leidenfrost point.
source (Wikip.) It is also observed with liquid nitrogen on a room-temperature surface.
Posts: 1896 | Location: U.S. | Registered: 06-03-02
It's also commonly seen in a steel rolling mill, where the water pouring over the rolls to keep them from getting too hot. is dancing all over the red hot plates and billets, etc.
