To what maximum percentage will NaF go into solution?

The maximum percentage to which NaF (sodium fluoride) can go into solution is influenced by its solubility in water. Sodium fluoride is considered to be fairly soluble in water, and common data suggests that it can dissolve to a maximum extent that is typically around 4% by weight in water at room temperature. This percentage reflects the saturation point beyond which additional NaF would not dissolve and would instead remain as a solid.

This knowledge is crucial for understanding the concentrations that can be safely used in various applications, particularly in environmental and public health contexts, such as water fluoridation and dental care, where maintaining proper fluoride levels is essential for efficacy and safety. The other options presented exceed this known solubility limit, indicating that while NaF can dissolve effectively at lower concentrations, higher percentages may lead to precipitation rather than further dissolution. Thus, 4% is recognized as the maximum practical limit for NaF solubility in aqueous solutions.