Question

Which one of the transition metal ions is coloured in aqueous solution?

• A. $C{u}^{+}$
• B. $Z{n}^{2+}$
• C. $S{c}^{3+}$
• D. $V^{4+}$

Answer 1

Answer: (D)

(a) Valence shell electron configuration of $C{r}^{3+}is{\left[Ar\right]}^{18}3d^{10};son=0$
(b) Valence shell electron configuration of $Z{n}^{2+}is{\left[Ar\right]}^{18}3d^{10};son=0$ (c) Valence shell electron configuration of $S{c}^{3+}is{\left[Ar\right]}^{18}3d^0;son=0$
(d)Valence shell electron configuration of $V^{4+}is{\left[Ar\right]}^{18}3d^1;son=1$
As $V^{4+}$ has one unpaired electron and so in presence of water as ligand it will undergo d-d transition of electron. Hence $V^{4+}$ ions will produce colour in the solution