What are the methods used to obtain acids? Write the reaction equations

Acids are obtained in several ways:
1) Interaction of acidic oxide with water; example: CO2 + H2O = H2CO3
2) Displacement of volatile acids, in the interaction of acids and salts; example: 2NaCl + H2SO4 (conc.) = Na2SO4 + HCl
3) Obtaining by the interaction of non-metals with hydrogen and with their further dissolution in water. example: H2 + Cl2 = 2HCl (hydrochloric acid, hydrogen chloride), but the resulting gas is not an acid, therefore, to obtain acid, you need to dissolve the HCl gas in water.