Acids interact with:
metals standing in the row of metal activity to the left of hydrogen. As a result of the reaction, salt is formed and water is released (substitution reactions), for example:
Mg + 2HCl → MgCl2 + H2 ↑.
basic and amphoteric oxides, as a result of the exchange reaction, salt and water are formed, for example:
K2O + 2HNO3 → 2KNO3 + H2O, Al2O3 + 6HCl → 2AlCl3 + 3H2O.
The exchange reactions between acids and bases are called neutralization reactions.
bases and with amphoteric hydroxides, forming salt and water:
KOH + HNO3 → KNO3 + H2O, Al (OH) 3 + 3HCl → AlCl3 + 3H2O.
salts, if the result is a substance practically insoluble in water (precipitation), a volatile substance (gas) or a weak electrolyte is formed.
H2SO4 + BaCl2 → BaSO4 ↓ + 2HCl,
Na2SiO3 + 2HNO3 → H2SiO3 ↓ + 2NaNO3.
NaCl (solid) + H2SO4 (conc.) → Na2SO4 + 2HCl ↑,
FeS + 2HCl → FeCl2 + H2S ↑.
2HCl + CaCO3 → CaCl2 + H2O + CO2 ↑
some acids decompose easily to form acidic oxide and water.
H2CO3⇄H2O + CO2 ↑,
H2SO3⇌ to H2O + SO2 ↑