I did a lab on spectrophotometric determination of iron in vitamin tablets, and I need to calculate the molarity of Fe(o-phenanthroline)3 in each solution and I have no idea how to calculate it. I know the concentration of Fe in the standard solutions in ppm.
And I have no idea what you did. Perhaps we can help if you post how the solutions were prepared.
To calculate the molarity of Fe(o-phenanthroline)3 in each solution, you need to convert the concentration of Fe in the standard solutions from ppm (parts per million) to moles per liter (Molarity). Here's how you can do it:
1. Determine the molar mass of Fe(o-phenanthroline)3. You can find this information in a periodic table or chemical database. Let's assume the molar mass is M g/mol.
2. Convert ppm to mg/L (milligrams per liter) for Fe in the standard solutions. Since 1 ppm is equivalent to 1 mg/L for dilute aqueous solutions, the concentration of Fe in mg/L is equal to the concentration of Fe in ppm.
3. Convert mg/L to moles per liter (Molarity) for Fe in the standard solutions. To do this, divide the concentration in mg/L by the molar mass (in g/mol) of Fe(o-phenanthroline)3.
Molarity = (Concentration in mg/L) / Molar mass (g/mol)
This will give you the molarity of Fe in each standard solution.
For example, let's assume you have a standard solution with a concentration of Fe equal to 10 ppm. If the molar mass of Fe(o-phenanthroline)3 is 300 g/mol, the calculation becomes:
Concentration in mg/L = 10 mg/L
Molar mass = 300 g/mol
Molarity = (10 mg/L) / (300 g/mol)
= 0.0333 mol/L
Therefore, the molarity of Fe(o-phenanthroline)3 in the standard solution with a concentration of 10 ppm is 0.0333 M.
Repeat this calculation for each standard solution to determine the molarity of Fe(o-phenanthroline)3 in each solution.