Răspuns:
2AlOH)3=> Al2O3 +3H2O
reactanti 2Al, 6O, 6H
produși de reactie 2 Al, 6O, 6H
MNaOH =23+16+1=40g/mol
m=3×40=120gNaOH
120gNaOH.......16gO
100gNaOH.....xgO
x=100×16/120=calculează