What are two chemicals commonly used as sources of fluoride in water treatment?

Sodium silicofluoride and hydrofluorosilicic acid are commonly used in water treatment as sources of fluoride because they effectively dissociate in water, releasing fluoride ions that can aid in the prevention of dental cavities and promote oral health.

Sodium silicofluoride is favored because it is stable, relatively inexpensive, and soluble in water, allowing for easy integration into water treatment systems. Hydrofluorosilicic acid also provides a controllable and efficient means of introducing fluoride into drinking water. Both chemicals are used to maintain optimal fluoride levels in communities to enhance dental health, aligning with public health initiatives aimed at reducing tooth decay.

Other options do not include chemicals typically utilized for fluoride treatment. For instance, calcium carbonate, sodium chloride, magnesium sulfate, sodium phosphate, potassium permanganate, and calcium fluoride have distinct applications in water treatment but do not serve as primary sources of fluoride. Thus, option B is clearly the most accurate choice in identifying common fluoride sources in water treatment processes.