Question

8.5g of sample of iron required just 75cm3 of 3.00M HCl to dissolve it and give a neutral solution.Calculate the percentage purity of the sample of iron.

Answer 1

Fe + 2HCl ==> FeCl2 + H2

millimoles HCl used = mL x M = 75 x 3 = 225
millimoles Fe = 1/2 x 225 = ?
mols Fe = 225/2000 = 0.1125
g Fe = mols x molar mass = 0.1125 x 55.85 = 6.28
% Fe in sample = (g Fe/g sample)*100 = ?
Check those calculations.