Question

When degenerate d-orbitals of an isolated atom/ion are brought under the impact of magnetic field of ligands, the degeneracy is lost. The two newly formed sets of d-orbitals,depending upon nature and magnetic field of ligands are either stabilized or destabilized. The energy difference between the two sets whenever lies in the visible region of the electromagnetic spectrum, then the electronic transition $t _{2 g } \rightleftharpoons e _{ g }$ are responsible for colours of the co- ordination compounds
$Ti ^{3+}( aq )$ is purple while $Ti ^{4+}( aq )$ is colourless because

• A. The difference between $t _{2 g }$ and $e _{ g }$ of $Ti ^{4+}$ is quite high and does not fall in visible region.
• B. There is no crystal field effect in $Ti ^{4+}$
• C. $Ti ^{4+}$ has $d ^{0}$ configuration.
• D. $Ti ^{4+}$ is very small ion than $Ti ^{3+}$ and does not adsorb any radiation.

Answer 1

Answer: (C)

Because of empty d-orbital there is no d-d transition and hence, $Ti ^{4+}$ is colourless.