Question

Consider the following statements with respect to lanthanides :
1. The basic strength of hydroxides of lanthanides increases from $La(OH)_3$ to $Lu(OH)_3$.
2. The lanthanide ions $Lu^{3+}$, $Yb^{2+}$ and $Ce^{4+}$ are diamagnetic.
Which of the statement(s) given above is/are correct?

• A. $1$ only
• B. $2$ only
• C. Both $1$ and $2$
• D. Neither $1$ nor $2$

Answer 1

Answer: (B)

Basic strength decreases from $La(OH)_3$ to $Lu (OH)_3$. Hence, $(1)$ is incorrect.
$Ce = [Xe] \,4f^1\, 5d^1 \,6s^2$; $Ce^{4+} = [Xe]$
$Yb = [Xe]\, 4f^{14}\, 6s^2$; $Yb^{2+} = [Xe] \,4f^{14}$
$Lu = [Xe] \,4f^{14}\, 5d^1\, 6s^2$; $Lu^{3+} = [Xe]\, 4f^{14}$