Express the concentration of a 0.0900 M aqueous solution of fluoride, F–, in mass percentage and in parts per million. Assume the density of the solution is 1.00 g/mL.
0.0900M = 0.0900 mols/L solution.
g = mols x atomic mass = 0.0900*19 = 1.71g.
mass solution = volume x density = 1000 mL x 1.0 g/mL = 1000 grams.
mass % = (g solute/grams soln)*100 = ?
Convert to mg/L and that is ppm
To express the concentration of a solution in mass percentage and parts per million (ppm), we need to calculate the mass of the solute (F–) and the mass of the solution.
First, let's calculate the mass of the solute (F–):
Given that the molarity of the aqueous solution of fluoride (F–) is 0.0900 M, it means there is 0.0900 moles of F– ions in 1 liter (or 1000 mL) of the solution.
To convert moles to grams, we need to multiply by the molar mass of fluoride (F–), which is approximately 19.0 g/mol.
Therefore, the mass of F– in the solution is:
mass of F– = moles of F– * molar mass of F–
mass of F– = 0.0900 M * 19.0 g/mol
mass of F– = 1.71 grams
Next, let's calculate the mass of the solution:
Given that the density of the solution is 1.00 g/mL, it means there is 1.00 gram of solution in 1 mL of the solution.
Since the volume of the solution is not provided, we assume that it is 1 liter (or 1000 mL).
Therefore, the mass of the solution is:
mass of solution = volume of solution * density
mass of solution = 1000 mL * 1.00 g/mL
mass of solution = 1000 grams
Now, let's calculate the concentration of the solution in mass percentage:
mass percentage = (mass of F– / mass of solution) * 100%
mass percentage = (1.71 g / 1000 g) * 100%
mass percentage = 0.171%
Finally, let's calculate the concentration of the solution in parts per million (ppm):
ppm = (mass of F– / mass of solution) * 10^6
ppm = (1.71 g / 1000 g) * 10^6
ppm = 1710 ppm
Therefore, the concentration of the 0.0900 M aqueous solution of fluoride (F–) is approximately 0.171% (w/v) and 1710 ppm.