Question
Question: Knowing that the Chemistry of lanthanoids (Ln) is dominated by its +3 oxidation state, which of the ...
Knowing that the Chemistry of lanthanoids (Ln) is dominated by its +3 oxidation state, which of the following statement is incorrect?
A
The ionic sizes of Ln (III) decrease in general with increasing atomic number.
B
Ln (III) compounds are generally colourless.
C
Ln (III) hydroxides are mainly basic in character
D
Because of the large size of the Ln (III) ions the bonding in its compounds is predominently ionic in character.
Answer
Ln (III) compounds are generally colourless.
Explanation
Solution
Most of the trivalent lanthanoid compounds except that of La3+ and Lu3+ are coloured both in the solid state and in the aqueous solution. The colour of these ions can be attributed due to the presence of unpaired f-electrons.