Question

Which of the following pairs of compounds is expected to exhibit same colour in aqueous solution?

• A. $FeC{l}_2,CuC{l}_2$
• B. $VOC{l}_2,CuC{l}_2$
• C. $VOC{l}_2,FeC{l}_2$
• D. $FeC{l}_2,MnC{l}_2$

Answer 1

The correct option is B $VOC{l}_2,CuC{l}_2$

$C{u}^{2+}:4s^{0}3d^9$

(Refer to Image 1)

No. of unpaired $e^{-}=1$

$V^{4+}:4s^{0}3d^1$

(Refer to Image 2)

No. of unpaired $e^{-}=1$

$\because$ The no. of unpaired $e^{-}$ for $C{u}^{2+}$ and $V^{3+}$ is same, i.e., $1$

$\therefore$ they exhibit same color.

As ions with same no. of unpaired $e^{-}$ exhibit same color.