Question

Which of the following ions is coloured in solution?

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

Answer 1

The correct option is D

$V{}^{3+}$

Transition elements form different coloured compounds. The compound in which metal ions has an unpaired electron that compound will be coloured.

A. The electronic configuration of $Z{n}^{2+}$ is [Ar]$3d^{10}$. No. of unpaired electron =0

B. The electronic configuration of $T{i}^{4+}$ is [Ar]$3d^0$. No. of unpaired electron =0

C. The electronic configuration of $C{u}^{+}$ is [Ar]$3d^{10}$. No. of unpaired electron =0

D. The electronic configuration of $V{}^{3+}$[Ar]$3d^2$
No. of unpaired electron = 2
As $V{}^{3+}$ contains 2 unpaired electron it will show colour.
$V{}^{3+}$ shows green coloured solution.