Which of the following compounds is likely to be coloured ?
Which of the following compounds is likely to be coloured ?
$\mathrm{TiCl}_{3}$
$\mathrm{Ti}\left(\mathrm{SO}_{4}ight)_{2}$
$\mathrm{Cu}_{2} \mathrm{Cl}_{2}$
$\mathrm{ScCl}_{3}$
Solution
Only $\mathrm{TiCl}_{3}$ has one unpaired electron in the lower $\mathrm{d}$ orbital which can be involved in $\mathrm{d-d}$ transition $\mathrm{Ti}\left(\mathrm{SO}_{4}ight)_{2}$ and $\mathrm{ScCl}_{3}$ have no electrons in $(\mathrm{n}-1) \mathrm{d}$ where as $\mathrm{Cu}_{2} \mathrm{Cl}_{2}$ has $(\mathrm{n}-1) \mathrm{d}^{10}$ configuration.
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