Question

Select the coloured compound amongst the following.

(At. no, $\text{Ti = 22, Cr = 24, Cu = 29, Zn = 30}$)

• A. $Ti{Cl}_4$
• B. $Cr{Cl}_3$
• C. $Zn{Cl}_2$
• D. $CuCl$

Answer 1

The correct option is B $Cr{Cl}_3$

Electronic configuration of transition metal ions in each salt is:

$T{i}^{4+}$: $\left[Ar\right]$

$C{r}^{3+}$: $\left[Ar\right]3d^3$

$Z{n}^{2+}$: $\left[Ar\right]3d^{10}$

$C{u}^{1+}$: $\left[Ar\right]3d^{10}$

Therefore electrons in d-orbital of $C{r}^{3+}$ can be excited, resulting in the coloured compound.

Option B is correct.