-Se lucreaza in moli :
8 moli xmoli
2 Fe + 3Cl2 = 2FeCl3
2moli 2moli
x=8.2 :2 =8moli FeCl3
-se afla masa de FeCl3
n=m :M [ n=nr. de moli ; m=masa subst. ; M=masa molara ]
m= n. M
m=8moli .162,5g/moli=1300 g FeCl3
MFeCl3=56+3.35,5=162,5------->162,5g/moli