From: David Fairman (thefairman@yahoo.com)
Date: Thu Dec 07 2000 - 16:26:13 PST
Message-ID: <20001208002613.29404.qmail@web124.yahoomail.com> Date: Thu, 7 Dec 2000 16:26:13 -0800 (PST) From: David Fairman <thefairman@yahoo.com> Subject: Re: pinhole Salting water
Here's something I've always wondered about. Salt is
supposed to raise the boiling point and lower the
freezing point of water. Well, when I used to do some
ski racing, during slushy spring days they would put
salt on the course to make the snow harder (and it
worked...the areas where they had put the salt were
firm while the areas with no salt were still soft and
slushy). If salt lowers the freezing point of water,
wouldn't this make the snow softer?
-Dave
--- Gene Thompson <gthompso@ccsf.cc.ca.us> wrote:
> There's a fun one you can do as a lab (as a cookbook
> style lab it's a
> blast because they don't know what to expect -- I
> don't tell them), or you
> can do it in a restaurant you plan on never
> returning to. Put a little
> puddle of fresh water on the table. Put a beaker
> (or glass) of crushed
> ice with a little water and a LOT of salt in it. Be
> careful not to spill
> salt in the puddle. Then hole the rim so the beaker
> (glass) doesn't move
> while you stir, stir, stir, stir. Restaurant knives
> are good for
> stirring. The glass quickly gets cold, frost forms
> at the base, and in
> about 5 minutes max you can't move the glass (oops,
> beaker) because it's
> frozen to the table.
>
> I caused my family great grief when we went out to
> dinner.
>
> Ellen Koivisto
> George Washington High School, SF
>
> On Wed, 6 Dec 2000 CGDonahoe3@aol.com wrote:
>
> > supposedly, adding salt to water raises the
> boiling temperature---thereby the
> > water absorbs more heat than pure water at 100 C.
> >
> > conversely, adding salt to water will lower its
> freezing temperature---why
> > salt is spread on roads to lower freezing
> temperature to keep vehicles from
> > sliding on ice.
> >
> > How to prove? Heat two beakers, one plain and
> one heavily salted and
> > measure temperature peak. Fresh = 100 c, salt
> water is greater.
> >
> > on the back side, have two beakers of heavily iced
> water, fresh measures at
> > about 0 C and salt water will go below -10C
> >
> > Easy to do with proper safety precautions.
> >
> > respectfully,
> >
> > cgd3
> >
> >
>
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> >
> >
> >
>
>
>
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=====
************************
* David Fairman *
* *
* thefairman@yahoo.com *
************************
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