Acids can be made by dissolving soluble non-metallic oxides in water.
Insoluble non metallic oxides however, do produce acidic solutions as they don't dissolve in water. Examples of insoluble non metallic oxides include carbon monoxide and nitrogen monoxide.
Soluble metallic oxides include carbon dioxide, sulfur dioixde, sulfur trioxide and nitrogen dioxide. They dissolve in water and produce acidic solutions.
Water + Carbon dioxide → Carbonic acid
H2O(l) + CO2(g) → H2CO3(aq)
Water + Sulfur dioxide → Sulfurous acid
H2O(l) + SO2(g) → H2SO3(aq)
Water + Sulfur trioxide → Sulfuric acid
H2O(l) + SO3(g) → H2SO4(aq)
Water + nitrogen dioxide → Nitric acid + Nitrous acid
H2O(l) + 2NO2(g) → HNO3(aq) + HNO2(g)
Sulfuric acid can be made directly from sulfur.
First the sulfur is burnt to produce sulfur dioxide.
S(s) + O2(g) →SO2(g)
The sulfur dioxide gas is then passed through a vandium catalyst in the contact process to yield sulfur trioxide gas.
SO2(g) + O2(g) ↔SO3(g)
The direct reaction of sulfur trioxide gas and water is too violent and produces a mist which is difficult to collect.
Instead the sulfur trioxide gas is passed through sulfuric acid to produce oleum, H2S2O7(l)
H2SO4(l) + SO3(g) → H2S2O7(l)
Water is finally added to the viscous oleum to produce sulfuric acid.
H2O(l) + H2S2O7(l) → 2H2SO4(aq)
Hydrochloric acid can be made by dissolving hydrogen chloride gas in water.
2HCl(g) + H2O(l)→ HCl(aq)
In the laboratory the reaction of sodium chloride and sulfuric acid can be used to generate HCl.
2NaCl + H2SO4 → Na2SO4 + HCl
In the chloro-alkali industry which is used to make sodium hydroxide, hydrogen and chlorine are by products.
2NaCl(aq) + 2H2O(l) → 2NaOH(aq) + H2(g) + Cl2(g)
The hydrogen and chlorine can be combined to produce hydrogen chloride in a HCl burner.
H2(g) + Cl2(g) → 2HCl(g)
The HCl is dissolved in deionised water and produces a very pure solution of hydrogen chloric acid.