Question

What is the concentration (in ppm) of Mn7+ in a 0.00300 M KMnO4 solution?  Note:  for dilute aqueous solutions, 1 ppm = 1 mg/L.

Answer 1

We know that there is 1 mole of Mn for every 1 mole of KMnO4, therefore the molarity of Mn is similar with KMnO4:

Mn = 0.00300 M

Molar mass of Mn is 54.94 g / mol. Molarity (M) is moles / L, therefore:

Mn = (0.00300 moles / L) * (54.94 g / mol) * (1000 mg / g)

Mn = 164.82 mg / L = 164.82 ppm