Question

Knowing that the Chemistry of lanthanoids $(Ln)$ is dominated by its $+3$ oxidation state, which of the following statements in incorrect ?

• A. Because of the large size of the $Ln (III)$ ions the bonding in its compounds is predominantly ionic in character
• B. The ionic sizes of $Ln (III)$ decrease in general with increasing atomic number
• C. $Ln (III)$ compounds are generally colourless
• D. $Ln (III)$ hydroxides are mainly basic in character

Answer 1

Answer: (C)

$Ln (III)$ compounds are generally colourless

Answer 2

$Ln^{+3}$ compounds are mostly coloured.