Question

Generally transition elements for coloured salts due to the presence of unpaired electrons. Which of the following compound will be coloured in solid state?

• A. $A{g}_{2}S{O}_4$
• B. $Cu{F}_2$
• C. $C{u}_{2}C{l}_2$
• D. $Zn{F}_2$

Answer 1

The correct option is A $A{g}_{2}S{O}_4$

A salt is coloured if transition ion contains unpaired d-electrons.

$A{g}^{+}-\left[Kr\right]4d^{10}$

$C{u}^{2+}-\left[Ar\right]3d^9$

$Z{n}^{2+}-\left[Ar\right]3d^{10}$

$C{u}^{+}-\left[Ar\right]3d^{10}$

In $Cu{F}_2,Cu$ is $+2$ contains an unpaired electron.

Hence, it is a coloured compound.