For soluble salts:
(a) Neutralization: – By the reaction of acid and base.
NaOH(ag) + HCL(aq) NaCL(ag) + H2O
(b) Dilute acid on metals:
2HCL(ag) + Zn(g) ZnCL2(ag) + H2(g)
For Insoluble salts
(a) By double decomposition
NSCL(aq) + AgNO3(ag) NaNO3(ag) + AgCL(s)
(b) By direct combination of constituent elements
Fe(s) + S(s) FeS(s)