MAl2O3=2AAl+3AO=2*27+3*16=102g/mol
n=m/M=51/102=0,5 moli Al2O3
4Al + 3O2 = 2Al2O3
4*27g Al...................2*102g Al2O3
x=.................................51g Al2O3
x=4*27*51/204= Calculeaza !!!
3 moli O2....................2 moli Al2O3
x.................................0,5 moli Al2O3
x=3*0,5/2= Calculeaza !!!