Chapter 15, Problem 80AE

Interpretation Introduction

Interpretation: The fluoridation of water as a means for preventing tooth decay is recommended by the U.S. Public Health Service $\left(\text{USPHS}\right)$. The given recommended concentration is $1\text{mg}{\text{F}}^{-}$ per liter. The maximum molarity of the calcium ions present in hard water if the fluoride concentration is at the $\text{USPHS}$ recommended level is to be calculated.

Concept introduction: Solubility is defined as the maximum amount of solute that can dissolve at a certain amount of solvent at certain temperature. The solubility product, $K_{\text{sp}}$ is the equilibrium constant that is applied when salt partially dissolve in a solvent. The solubility product of dissociation of ${\text{A}}_x{\text{B}}_y$ is calculated by the formula,

$K_{\text{sp}}={\left[\text{A}\right]}^x{\left[\text{B}\right]}^y$