Question

Explain the following: La(OH)₃ is more basic than Lu(OH)₃.

Answer 1

La(OH)3 isis more basic than Lu(OH)3. Due to lanthanoid contraction the size of lanthanoid ions decreases regularly with increase in atomic size .As a result of decrease in size,their covalent character between lanthanoid ion and OH ion increases from La3+to Lu3+. Therefore the basic character f hydroxides decreases from La(Oh)3 to Lu(OH)3