Most basically, does the test for fluoride include the fluoride of calcium fluoride, which is insoluble?
What amount of sodium fluosilicate, fluosilicic acid, and sodium fluoride, individually, must be added to 100 g (or liter, or whatever) of water at ~20 C to achieve a 1 ppm concentration of fluoride ions (as determined by ASTM D1179)?
Do these compounds dissociate completely? What amount of insoluble (from pubchem) calcium fluoride must be added? The test for fluoride measures only monatomic F- ions, correct?
How about a soluble but undissociating (like ethanol) fluoride salt, if one exists?
To convert fluoride compound into fluoride ion for sodium fluoride (NaF) divide by 2.21. For sodium silicofluoride (Na2SIF6) divide by 1.65. For fluorosilicic acid (H2SiF6) divide by 1.26. Thus, 1 mg of NaF contain 0.45 mg F ion, Na2SIF6 contain 0.61 mg F ion, and H2SiF6 contain 0.79 mg F ion. Collectively, the sum of F ions in one mg of these compounds is 1.85 mg. If all these compounds are used to fluoridate water at one mg F ion per liter, then the 1.85 mg should added to 1,850 ml of water OR 0.1 mg per 100 ml. If individually then turn to the conversion ratio as above. Good luck.
So these compounds dissolve completely? How about calcium fluoride? The test for fluoride measures only monatomic F- ions, correct?
I guess my basic question is, does the test for fluoride include the fluorine of the calcium fluoride molecule?
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