you are a public health officer in the water treatment facility for a city of 50,000 people . A concentration of 1.0 ppm of fluoride in the drinking water is sufficient for the purpose of helping to prevent tooth decay. The compund normally chosen for fluoridation is the same as is found in some toothpaste, sodium fluoride, NaF. Calculate how many kilograms of sodium fluoride you will need to purchase in order to fluoridate the city's water supply for one year, based upon your estimate that the average daily consumption of water is is 150 gallons per person.

You want 1 ppm F. That is 1 mg/L F and

1 mg F x (molar mass NaF/atomic mass F) = ? mg NaF/L.

150 gal/person x 50,000 persons = ? gallons/yr
Convert gallons/yr to L/yr.
? mg NaF/L x #L = mg NaF/yr
Then convert mg NaF to kg NaF.

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To calculate the amount of sodium fluoride needed to fluoridate the city's water supply for one year, we need to follow these steps:

Step 1: Calculate the total water consumption per year
Multiply the average daily consumption of water per person (150 gallons) by the number of people in the city (50,000) and then by the number of days in a year (365).

150 gallons/person/day * 50,000 people * 365 days/year = X gallons/year

Step 2: Convert gallons to liters
Since the concentration of fluoride is given in parts per million (ppm), we need to convert gallons to liters as follows:

1 gallon = 3.78541 liters

X gallons/year * 3.78541 liters/gallon = Y liters/year

Step 3: Convert liters to milliliters
Since the concentration of fluoride is typically measured in milligrams per liter (mg/L), we will convert liters to milliliters:

1 liter = 1,000 milliliters

Y liters/year * 1,000 milliliters/liter = Z milliliters/year

Step 4: Calculate the total mass of fluoride needed
Since the fluoride concentration is given in parts per million (ppm), which is equivalent to milligrams per liter (mg/L), we can calculate the mass of sodium fluoride needed using the following equation:

Total mass (in grams) = Z milliliters/year * 1 ppm * 1 mg/L * 1 gram/1,000 mg

Step 5: Convert grams to kilograms
Finally, to obtain the mass of sodium fluoride needed in kilograms, divide the total mass in grams by 1,000.

Total mass (in kilograms) = Total mass (in grams) / 1,000

Performing the calculations, we get:

Step 1: X gallons/year = 150 gallons/person/day * 50,000 people * 365 days/year
Step 2: Y liters/year = X gallons/year * 3.78541 liters/gallon
Step 3: Z milliliters/year = Y liters/year * 1,000 milliliters/liter
Step 4: Total mass (in grams) = Z milliliters/year * 1 ppm * 1 mg/L * 1 gram/1,000 mg
Step 5: Total mass (in kilograms) = Total mass (in grams) / 1,000

By following these steps, you should be able to calculate the exact amount of sodium fluoride you will need to purchase to fluoridate the city's water supply for one year.