Chemistry - Coordination Chemistry Question with Solution | TestHub

Solution:

The complex ion is $[Ti(L{)}_6{]}^{3+}$, where L is a ligand (likely water, H₂O, in an aqueous solution). Titanium in this complex has an oxidation state of +3.

1. Determine the electronic configuration of $T{i}^{3+}$:

The atomic number of Ti is 22.

Electronic configuration of Ti: $[Ar]3d^{2}4s^2$.

Electronic configuration of $T{i}^{3+}$: $[Ar]3d^1$.

2. Crystal Field Theory (CFT) explanation:

In an octahedral complex, the five degenerate $d$-orbitals split into two sets:

- Three lower energy $t_{2g}$ orbitals.

- Two higher energy $e_g$ orbitals.

The single $d$-electron in $T{i}^{3+}$ occupies one of the $t_{2g}$ orbitals.

3. Light absorption and color:

When white light passes through the solution, the $T{i}^{3+}$ ion absorbs light energy corresponding to the $t_{2g}\to e_g$ electronic transition. The energy difference (${\Delta }_o$) between the $t_{2g}$ and $e_g$ orbitals corresponds to the energy of green-yellow light.

Since green-yellow light is absorbed, the complementary color, which is purple (or violet-red), is transmitted, giving the complex its observed color.

The complex $[Ti(H_{2}O{)}_6{]}^{3+}$ is known to be purple/violet. The option "Red" is the closest description among the choices, indicating a color in the red-violet spectrum.

The final answer is $\boxed{Red}$.