99 Percentile Qs Bank for JEE MainChemistryd and f Block Elements
Which of the following statements is not correct?
Options
- ALa OH 3 is less basic than Lu OH 3 .
- BIn the lanthanide series, the ionic radius of Ln 3 + ions decreases.
- CLa is actually an element of transition series rather than lanthanide series.
- DAtomic radii of Zr and Hf are same because of lanthanide contraction.
Correct answer
A. La OH 3 is less basic than Lu OH 3 .
Step-by-step solution
The basic character of lanthanide hydroxides decreases as we go from left to right with increasing atomic number, i.e., from La OH 3 to Lu OH 3 . This is due to the lanthanide contraction. Lanthanide contraction is a gradual decrease in the size of lanthanide with the increasing atomic number due to an increase in the nuclear charge. This is caused by the poor shielding of 4 f electrons. In the case of metal hydroxides, greater the size of metal, more is the bond length of M - OH . Hence, it becomes easier to break