Which among the following cations will not form coloured compounds? (Atomic number $\mathrm{Cu}=29,…
Which among the following cations will not form coloured compounds?
(Atomic number $\mathrm{Cu}=29, \mathrm{Ti}=22, \mathrm{~V}=23, \mathrm{Mn}=25$ )
$\mathrm{V}^{3+}$
$\mathrm{Ti}^{3+}$
$\mathrm{Cu}^{+}$
$\mathrm{Mn}^{2+}$
Solution
$\mathrm{Cu}^{+}$ion will not form coloured aqueous solution as it does not contain unpaired electrons. $\mathrm{Cu}^{+}$ion with $3 \mathrm{~d}^{10}$ outer electronic configuration has zero unpaired electrons.