Question

Write two differences between double salt and co-ordination compounds.

Hint:

Remember: Double salts exist only in solid state, while coordination compounds exist in both solid and solution states.

Answer 1

1. Dissociation: Double salts (e.g., Mohr's salt) completely dissociate into their constituent simple ions when dissolved in water. Coordination compounds (e.g., Potassium ferrocyanide) do not completely dissociate; the complex ion remains intact.
2. Properties: The properties of a double salt are essentially the same as those of its constituent compounds. The properties of a coordination compound are different from its constituents.
3. Valency: In double salts, the metal exhibits normal valency. In coordination compounds, the metal satisfies two types of valencies: primary (oxidation state) and secondary (coordination number).