Question

$T{i}^{3+}$ transition metal ion is purple in colour while $T{i}^{4+}$ metal ion is colourless due to

• A. vacant d-orbitals
• B. unpaired electrons in d orbitals
• C. completely filled d-orbitals
• D. None of these

Answer 1

Answer: (A)

Transitional metal ions having completely filled or empty d-orbitals,
ie, $(n-1)d^{10}$
or $(n-1)d^0$
configuration are colourless while transitional metal ions having $(n-1)d^{1-9}$
configuration are coloured due to $d-d$ transition.
$Ti(22):[Ar]3d^{2}A{s}^2$
$T{i}^{3+}:[Ar]3d^{1}4s^o:$ purple
$T{i}^{4+}:[Ar]3d^{0}4s^o:$ colourless
Hence, $T{i}^{4+}$ metal ion is colourless due to vacant d-orbitals.