Answer. Soluble salts are often prepared in water. These can be prepared by different methods
(a) By the reaction of an acid and a metal: (Direct Displacement method)
This is direct displacement method in which hydrogen ion of acid is replaced by a reactive metal, i.e. calcium, magnesium, zinc and iron, e.g,
Acid + Metal ———> Salt + Hydrogen gas
2HCl(aq) + Mg(s)—————> MgCl2(aq) + H2(g)
(b) By the reaction of an acid and a base: (Neutralization method)
It is a neutralization reaction in which acid and base react to produce a salts and water.
Acid + Base ———> Salt + Water
HCl(aq) + NaOH(aq) —————> NaCl(aq) + H2O(1)
(c) By the reaction of an acid and metallic oxide:
Mostly the insoluble metallic oxides react with dilute acids to form salt and water.
Acid + Metallic oxide ———> Salt + Water
H2SO4(aq) + CuO(aq) —————> CuSO4(aq) + H2O(aq)
(d) By the reaction of an acid and a carbonate
Dilute acids react with metallic carbonates to produce salts, water and carbon dioxide gas.
2HNO3(aq)+ Na2CO3(aq) —————> NaNO3(aq) + H2O + CO2(g)