Acid Base Neutralization Reaction

1. Base + acid → salt + water
Example: HCl + KOH → KCl + H₂O
2. Base oxide + acid → salt + water
Example: 2NaOH + CO₂ → Na₂CO₃+ H₂O
3. Base oxide + acid → salt + water
Example: CaO + 2HCl → CaCl₂ + H₂
4. Acid oxide + base oxide → salt base
Example: SO₃ + CaO → CaSO₄
5. Metal + acid → salt + H₂ gas
Example: Fe + H₂SO₄ → FeSO₄ + H₂
6. Metal1 + salt1 → salt2 + metal2
Example: FeSO₄ + Ca → Fe + CaSO₄

Terms: Salting at fifth number, the metal must be on the left H + in the array Volta. Salting at sixth number, metal1 must be located on the left in metal2 array Volta.
Volta array:
Li - K - Ba - Ca - Na - Mg - Al - Mn - Zn - Cr - Fe - Co - Ni - Sn - Pb - (H) - Sb - Bi - Cu - Hg - Ag - Au - Co