Re: [NTLK] OT humidity

From: Mark Ross (markr13_at_comcast.net)
Date: Sat Jun 29 2002 - 22:07:59 EDT


>
>on 6/28/02 9:02 PM, Sushi at Sushi_at_ragingbull.com wrote:
>
>> Hmmm...I don't know...at 100% humidity, it sure feels like you are in the
>> pool! ;-) :-)
>
>That's why you grow gills if you live in P'cola for long. :-)
>
>BTW, fill a cooking pan with water, and then add sugar until it can't hold
>any more. Now heat up that water on the stove, and watch the rest of that
>sugar disappear. Saturation is definitely relative to temp. :-) (If I recall
>correctly my chemistry class, it was called super saturation??)
>--
>Jon Glass

Oh, boy. Now you've got me started. The degree to which any solvent can
hold a solute is directly related to temperature as well as pressure.
Saturation is the point at which a solvent will no longer hold any more
solute at a given P and T. Super saturation is when you cool the solvent
and it appears to hold more than it should based upon the measurements
taken when you were heating it up. This occurs because many crystalline
materials will not fall out of solution until a seed crystal forms. If
you touch, shake or otherwise disturb a super saturated solution, the
crystal seeds can form and the solute will fall out all at once until it
reaches the correct level for saturation at that temperature.

In the example of water (solute) in air (solvent), the amount maximum
amount of water that can be held at a given temperature and pressure is
called 100% relative humidity. It is not possible to hold more than that
as the air is saturated with water in this state.

Whew! I feel much better now.

Mark Ross
markr13_at_comcast.net

-- 
Read the List FAQ/Etiquette: http://www.newtontalk.net/faq.html
Read the Newton FAQ: http://www.guns-media.com/mirrors/newton/faq/
This is the NewtonTalk mailing list - http://www.newtontalk.net



This archive was generated by hypermail 2.1.2 : Wed Jul 03 2002 - 14:03:10 EDT