Question

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

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

Answer 1

The correct option is B $Cu{F}_2$

The respective transition elements exists in

$A{g}^{+}-{4d}^{10}5s^0$, (have completely filled d orbital)

$C{u}^{+2}-3d^{9}4s^0$, (have incompletely filled d orbital)

$Z{n}^{+2}-3d^{10}4s^0$ , (have completely filled d orbital)

$C{u}^{+1}-3d^{10}4s^0$ (have completely filled d orbital),

Since, $C{u}^{+2}$ has unpaired electron it will show electron transitions.

Hence will be coloured.