RE: [APD] PPM Concentrations

["Gomer" <iegomer at hotmail_com>]

Steve, I thought about this a little and came up with a very simple
solution.....don't change anything :D

Let me explain.  PPM is defined as mg/L.  That is mg of solute/ liter of
SOLUTION, not solvent.  This means that it doesn't matter how much water you
add, just the final volume.

Ie, suppose Ksp wasn't an issue (ie, complete solvation) and you want
1,000,000 ppm ;)

1) you put 100g of NO3 in 100mL of water.  This is INCORRECT.  
2) you put 100g of NO3 in as much water as needed to yield 100mL of
solution.  THIS is CORRECT.  

.or perhaps I don't understand this correctly (I usually deal with gasses
where PPM has a different definition.  I didn't think it was wrong to
consider PPM solutions just like molarity).

-_Tony

--------

It seems that this equation is OK for small concentrations but for larger
concentrations I need to add the volume of the compound to the volume of the
water.  In other words the solution volume equals the solvent volume plus
the solute volume (this is the wet volume of the compound).  
Aquatic-Plants at actwin_com
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