Răspuns:
Explicație:
-se afla masa de Fe pur
mp= p . mi :100 p=80% [ 100 - 20=80 ]
mp=80 . 500 : 100=400 g Fe pur
400: 2=200g
200g xg
3 Fe +2 O2= Fe3O4
3 .56g 172g
x=200.172 : 168=204,76 gFe3O4
n= 204, 76 g: 172g/moli=1,19 moli Fe
Fe + 2HCl = FeCl2 +H2
MFe3O4=3.56 + 4.16=172-------> 172g/moli