In article >,
(Vince Poroke) wrote:

> > >
> > > Clarification:
> > > Room temperature water can boil faster than hot water out of the tap
> > > if.... the room temperature water was previously boiled and allowed to
> > > cool. That's because boiling gets rid of the dissolved oxygen usually
> > > found in water, making it easier for the water to boil the second time
> > > around.
> >
> > Absolute nonsense. I mean, real world-class nonsense. But thanks, I'll have
> > to add this to the myth.

> I can only base this information on a group that spends their time
> doing an outstanding job of busting myths "Straight Dope". They could
> be wrong but that is what they stated.
> http://www.straightdope.com/classics/a2_101c.html

Doesn't seem believable to me. However, I found a reference that says
that water without disolved gases can take *longer* to boil *sometimes*:

[begin quote]

In regards to your discussion of superheating water in a microwave oven,
I've found that it occurs most often when (1) I reheat water that has been
heated before and (2) I heat water that has sat in the cup
overnight. Why does that seem to reduce the number of seed bubbles? - JS

Both processes allow dissolved gases to escape from the water so
that they can't serve as seed bubbles for boiling. When you heat water and
then let it cool, the gases that came out of solution as
small bubbles on the walls of the container escape into the air and
are not available when you reheat the water. When you let the water sit
out overnight, those same dissolved gases have time to
escape into the air and this also reduces the number and size of
the gas bubbles that form when you finally heat the water. Without those
dissolved gases and the bubbles they form during heating it's
much harder for the steam bubbles to form when the water reaches
boiling. The water can then superheat more easily.


[end quote]


http://home.howstuffworks.com/framed...ave_ovens.html


What the above is saying is that under certain conditions (no bubbles and
perfectly smooth container), water can be heated beyond the boiling
point. However, once something disturbs the superheated water, it will
basically explode.

--
Dan Abel
Sonoma State University
AIS