Sean,
I can't find my old "text scrolls" from alchemy, but off the top of my
head I seem to dimly recall the following chants, or mantras, that may
be illuminating.
Of course it is a "universal solvent". Meaning that a great many things
are soluble in water. And, as you well know, saturating water with a
soluble ingredient does not reduce the mixture's ability to be saturated
by yet another chemical. And yet another.
However, I doubt, if you look at solubility's tables, you will find
aluminum, iron, copper, etc. amongst those with any significant
solubility in water. Rust is an oxidation process, not a solubility
process, and requires the presence of oxygen.
This does not mean, however, that the process of dissolution of elements
by galvanic corrosion of dissimilar elements can not take place. This
is an entirely different process, and is similar to electroplating.
However, it does require that the medium be electrically conductive.
And yet another process "table" is used, the "galvanic table".
You will remember that water is a poor conductor of electricity. But,
adding some ions to the water, my means of dissolving chemicals, and you
have a conductive media and electrolysis, or "electroplating" can
occur. Materials higher on the galvanic table are removing those
materials lower on the table. Iron is fairly low, aluminum is higher,
and magnesium is right up there. Which is why placing electrically
connected (grounded) sacrificial magnesium metal in the cooling medium
liquid system protects the lower activity elements, such as your
aluminum parts, from being eaten away.
Not discussed is the process of solubility in another media, such as an
acid. Water can be MADE into an acid with the solution of suitable
chemicals. Sulfuric Acid, Nitric Acid, and all those lovely things, are
created by dissolving their soluble salt forms in water.
So, what is the message?
It is NOT the water that is doing you in, it is the contaminants in the
water that change it from an insulator into a conductor, and the
contaminants that change if from a neutral liquid (pH = 7 into an acid
(a pH lower than 7), or corrosive base (a pH larger than 7). And can
change it from a poor conductor of electricity to a good one. Remember,
my memory may have the number directions reversed throughout this tale,
so bear with an old bear.
So, keep your water PURE (like "distilled", as in Kentucky). Add only
proven ingredients that accomplish other goals, such as anti-freeze or
water pump lubricant (often combined) from companies that understand
what they are doing (Prestone, etc.). Stay away from contaminated water
that has unknown junk in it to start these wicked processes, like
"garden hose water", "well water", "spring water", "mineral water", tap
water - which is G-d knows what, and unknown processes such as "purified
water". "De-mineralized" water might be OK, but why chance it when the
distilled water is on the next shelf at the grocery store, and is
defined by law. Read the label, the stockers are not sensitive to these
fine nuances.
At $1 a bottle, it's good insurance. I make it a policy never to drink
anything that has not been distilled first. Most of it is diluted with
60% water and is called "80 Proof". :-) Must be good for you, right?
I'd recommend it for automotive use, but it's "agin' the law" in most
states, except in your windshield washer.
If I were a Ph.D. in Chemistry, I might remember it better. Anyone want
to launch a Mars Rover? ;-)
Steve
Drmoonstone@aol.com wrote:
>Actually referring to several textbooks from my grad school chem classes and
>they do refer to water as the universal solvent. Guess the text books are bad.
>
>Moonstone
>
>
>
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Steve Laifman
Editor
http://www.TigersUnited.com
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