Răspuns:
I. Na → Na₂O → NaOH → NaNO₃ → NaNO₂
1. 4Na + O₂ → 2Na₂O
2. Na₂O + H₂O → 2NaOH
3. NaOH + HNO₃ → NaNO₃ + H₂O
4. 2NaNO₃ → 2NaNO₂ + O₂↑
II. Ca → CaO → Ca(OH)₂ → Ca(NO₃)₂ → CaSO₄
1. 2Ca + O₂ → 2CaO
2. CaO + H₂O → Ca(OH)₂
3. Ca(OH)₂ + 2HNO₃ → Ca(NO₃)₂ + 2H₂O
4. Ca(NO₃)₂ + H₂SO₄ → CaSO₄ + 2HNO₃
III. Li → Li₂O → LiOH → Li₃PO₄ → P₂O₃
1. 4Li + O₂ → 2Li₂O
2. Li₂O + H₂O → 2LiOH
3. 3LiOH + H₃PO₄ → Li₃PO₄ + 3H₂O
4. reacția nu este posibilă
-Mihai
