Express the concentration of a 0.0730 M aqueous solution of fluoride, F−, in mass percentage and in parts per million (ppm). Assume the density of the solution is 1.00 g/mL.

Answer 1

0.0730 mols / L x 19.0 g F- / mol = 1.387 g F- / L

1 L x 1000 ml / L x 1.00 g /ml = 1000 g = mass of solution

mass % F- = 1.387 g / 1000 (x100%) = 0.139% by mass

For ppm, we have the following calculation:

1.387 g / L x 1000 mg /g = 1387 mg/L = 1387 ppm