Question

Consider the following statements
I. $La(OH{)}_3$ is least basic among hydroxides of lanthanides.
II. $Z{r}^{4+}$ and $H{f}^{4+}$ possess almost the same ionic radii.
III. $C{e}^{4+}$ can act as an oxidising agent.
Which of the above is/are true?

• A. I and III
• B. II and III
• C. II only
• D. I and II

Answer 1

Answer: (B)

$La(OH{)}_3$ is most basic. Hence, $(I)$ is wrong. $(II)$ is correct due to lanthanoid contraction. $(Ill)$ is correct because $C{e}^{4+}$ tends to change to stable $C{e}^{3+}$.