Question

Why is the separation of lanthanoid elements difficult?

Answer 1

1. Lanthanoids have very similar chemical properties and mainly exhibit +3 oxidation state.
2. Due to lanthanoid contraction, their ionic radii decrease gradually but remain very close in size.
3. They form compounds with similar crystal structures and solubilities.
4. Similar ionic size, charge, and electronic configuration make their behavior alike.
5. These factors cause their salts and complexes to have very similar properties, complicating separation processes.

Thus, their similar chemical and physical characteristics hinder easy separation.