Question

what is complex salts and double salts?

Answer 1

Double salts are molecular compounds which are formed by the evoporation of solution containing 2 or more salts in stoichiometric proportions. They dissociate into their constituent ions in solution

eg: K₂SO₄.Al₂(SO4)₃.24H₂O ------> 2K⁺ + 2Al³⁺ + 4SO₄^2- + 24H₂O

A complex compound is a compound formed from a lewis acid and a lewis base. They do not dissociate into its constituent ions in solutions

eg: Fe(CN)₂ + 4KCN ---> K₄[Fe(CN)₆]

K₄[Fe(CN)₆] on dissociation gives 4K⁺ + [Fe(CN)₆]^4-

In K₄[Fe(CN)₆] the individual components lose their identity. The metal of the complex ion is not free in solution unlike the metal in double salt solution.