MO2=32g/mol
n=m/M=640/32=20 moli O2
n=V/Vm=>V=n*Vm=20*22,4= Calculeaza !
4Al + 3O2 => 2Al2O3
3 moli O2,,,,,,,,,,,,,,,,,,,,,2*102g Al2O3
20 moli O2.....................xg Al2O3
x=204*20/3=
MAl2O3=2AAl+3AO=2*27+3*16=102g/mol
M-masa molara,g/mol
A-masa atomica
Vm-volumul molar (c.n) = 22,4 L
m-masa,g
n-nr de moli