PTHH: Fe +2 HCl -> FeCl2 + H2
nH2= 6,72/22,4= 0,3(mol)
=> nFe= nH2= 0,3(mol)
=> mFe= 0,3. 56= 16,8(g)
=> %mFe= (16,8/23,2).100\(\approx\)72, 414%
nH2 = 6.72/22.4 = 0.3 mol
Fe + 2HCl --> FeCl2 + H2
0.3_________________0.3
mFe = 16.8 g
%Fe = 16.8/23.2*100% = 72.41%