Re: Aluminum Milling Media

A solution of NaOH and H2O is saturated at 50% NaOH. The dissolution of NaOH in H2O has a deltaH of -44.45 kJ/mol for diluted aqueous. Saturating a Mole of water -will- boil the water. As for why steam evolution from small amounts in a milling operation, NaOH in crystalline form takes up water a lot more slowly than when it has had its surface area enormously increased by milling. In fine powdered form it will suck the moisture out of the air and at the same time evolve heat. The heat inside a small container is enough to simultaneously drive some of the water back out of the NaOH and remember that heated air also increases internal pressure in the small container. The small amount of water escaping from the pressurized, heated, container cools as it expands and in cooling condenses as visible water vapor. The expansion of the heated gas/water mixture will cool it -below- room temperature.

--


Don Thompson

Stolen from Dan: "Just thinking, besides, I watched 2 dogs mating once,
and that makes me an expert. "

There is nothing more frightening than active ignorance.
~Goethe

It is a worthy thing to fight for one's freedom;
it is another sight finer to fight for another man's.
~Mark Twain


"Richard Casady" <richardcasady@xxxxxxxxxxxxx> wrote in message news:485b3f29.665738234@xxxxxxxxxxxxxxxxxxxxxxxxxx
On Sat, 19 Apr 2008 10:33:35 -0700 (PDT), robgood@xxxxxxxxxxx wrote:

Let's just say the solvation of
NaOH by a mole of H2O has enough energy to boil more than a mole of
H2O.

The solution of a mole of NaOH yields less than half the energy
required to boil a mole of water. You are saying that 8 or so grams of
water will dissolve 40 grams of NaOH? That is interesting, if true.

Casady

.

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