Fluoridation is the process of adding flourine compounds to drinking water to help fight tooth decay. A concentration of 1ppm of flourine is sufficient to the purpose (1ppm means one part per million, or 1g of flourine per 1million g of water). The compound normally chosen for floridation is sodium fluoride, which is also added in some toothpastes.
Calculate the quantity of sodium in kilograms needed per year for a city of 50,000 people if the daily consumption of water per person is 115.0 gallons. (sodium flouride is 45.0 percent flourine by mass. 1 gallon=3.79L; 1 ton=2000 lb; 1lb=453.6g; the density of water is 1.0g/mL)