Now if your lab partner determined that there were 1.157 x 1020 atoms of Mn in an unknown sample of KMnO4, how many milligrams would the unknown sample weigh?
Was it pure? if so, there are 6.02E23 atoms in a molecule; therefore, there are
1.157E20 molecules x (1 mol/5.02E23) = ? mols KMNO4.
mols KMnO4 x molar mass = grams KMnO4 = ?
Convert to mg.