Most basic hydroxide among the following is

Options

A. `Lu(OH)_(3)`
B. `Eu(OH)_(3)`
C. `Yb(OH)_(3)`
D. `Ce(OH)_(3)`

Answer

D

Explanation

Due to lanthanide contraction,the size of `M^(3+)` ion (ie,`Lu^(3+),Eu^(3+),Yb^(3+) and Ce^(3+)`) decreases and thus, the basic strenth of their hydroxides decreases.
The order of size of given `M^(3+)` ions is
`Ce^(3+)gtEu^(3+)gtYb^(3+)gtLu^(3+)`
`therefore` The order of basic strength of hydroxides is
`Ce(OH)_(3)gtEu(OH)_(3)gtYb(OH)_(3)gtLU(OH)_(3)`