Question: The United States Public Health Service USPHS recom mends the fluoridation
The United States Public Health Service (USPHS) recom-mends the fluoridation of water as a means for prevent-ing tooth decay. The recommended concentration is 1 mg F2/L. The presence of calcium ions in hard water can precipitate the added fluoride. What is the maximum molarity of calcium ions in hard water if the fluoride concentration is at the USPHS recommended level? (Ksp for CaF2 = 4.0 × 10-11.)
Answer to relevant QuestionsSlaked lime [Ca(OH)2] is used to soften hard water by removing calcium ions from hard water through the reaction Ca(OH)2(aq) + Ca2+(aq) + 2HCO3-(aq) → 2CaCO3(s) + 2H2O(l) What is the valence electron configuration for Group 4A elements? Group 4A contains two of the most important elements on earth. What are they, and why are they so important? How does metallic character change as one goes ...Write equations describing the reactions of Sn with each of the following: Cl2, O2, and HCl. Elemental nitrogen exists as N2, whereas in the gas phase the elements phosphorus, arsenic, and antimony consist of P4, As4, and Sb4 molecules, respectively. Give a possible reason for this difference between N2 and the ...Phosphoric acid (H3PO4) is a triprotic acid, phosphorous acid (H3PO3) is a diprotic acid, and hypophosphorous acid (H3PO2) is a monoprotic acid. Explain this phenomenon.
Post your question