Question

you pipetted a 10.00ml of solution with a concentration of 0.200g/l of pure iron into a 100.00 ml volumetric flask to make a stock solution

a) calculate the concentration of the stock solution in mole/l of iron
b) calculate the concentration of the stock solution in mg/l

Answer 1

First, you will have a tough time pipetting a SOLID iron solution. It just aint made that way but I'll go along with the story.
0.2 g/L = 200 mg/L
mols = grams/atomic mass = 0.2/55.85 = ? mols/L