1) Na₂O + H₂O = 2NaOH.
SO₃ + H₂O = H₂SO₄.
P₂O₅ + H₂O = H₃PO₄.
BaO + H₂O = Ba(OH)₂.
2) 4Li + O₂ = 2Li₂O.
S + O₂ = SO₂.
2Al + 3O₂ = 2Al₂O₃.
C + O₂ = CO₂.
3) K₂O + H₂O = 2KOH.
SO₂ + H₂O = H₂SO₃.
CaO + H₂O = Ca(OH)₂.
CO₂ + H₂O = H₂CO₃.
4) Zn(OH)₂ t° → ZnO + H₂O.
2Fe(OH)₃ t° → Fe₂O₃ + 3H₂O.
2Cr(OH)₃ t° → Cr₂O₃ + 3H₂O.
Ni(OH)₂ t° → NiO + H₂O.