Final answer:
To calculate the concentration of F-, the mass of NaF is converted to moles, the volume of water to liters, and then the molarity of F- is found. The absolute uncertainty is determined by combining the relative uncertainties of mass and volume, and applying this to the calculated molarity. The concentration of F- is 0.01084 ± 0.000065 M.
Step-by-step explanation:
To calculate the concentration of F- in solution, we will use the mass of NaF and the volume of water provided. First, we convert the mass of NaF to moles using its molar mass:
Mass of NaF = 0.0737 g
Molar mass of NaF = 41.99 g/mol
Moles of NaF = Mass / Molar mass = 0.0737 g / 41.99 g/mol = 0.001755 mol
Next, we convert the volume of water to liters:
Volume of solution = 162.00 mL = 0.16200 L
Now we can calculate the molarity of F- by dividing the moles of NaF by the volume of water in liters:
Molarity (M) = Moles of NaF / Volume of solution in L = 0.001755 mol / 0.16200 L = 0.01084 M
To find the absolute uncertainty of the F- concentration, we need to calculate the uncertainty in the mass of NaF and the volume of solution, then apply the formula for the propagation of uncertainty:
Uncertainty in mass = ±0.0004 g
Uncertainty in volume = ±0.09 mL = ±0.00009 L
The relative uncertainty in mass (um) = Uncertainty in mass / Mass of NaF = 0.0004 g / 0.0737 g = 0.0054
The relative uncertainty in volume (uv) = Uncertainty in volume / Volume of solution = 0.00009 L / 0.16200 L = 0.00056
The combined relative uncertainty = um + uv = 0.0054 + 0.00056 = 0.00596
We then multiply the molarity of F- by the combined relative uncertainty to find the absolute uncertainty:
Absolute uncertainty = Molarity of F- * Combined relative uncertainty = 0.01084 M * 0.00596 ≈ 0.000065 M
Therefore, the concentration of F- is 0.01084 ± 0.000065 M.