Q. Among the following the compound that is both paramagnetic and coloured is
A) $K_{2}{Cr}_{2}O_{7}$
B) $\left( {NH}_{4} \right)_{2}\lbrack{TiCl}_{6}\rbrack$
C) ${VOSO}_{4}$
D) $K_{3}\lbrack Cu(CN)_{4}\rbrack$
Explanation
(c)
${VOSO}_{4}$ is paramagnetic as well as coloured compound.
The oxidation state of vanadium in ${VOSO}_{4}$ is +4.
V [Z=23]=[Ar]$3d^{3}\ 4s^{2}$
$V^{4 +}$[Z=23]=[Ar] $3d^{1}\ 4s^{0}$
It has one unpaired electron hence, it is paramagnetic in nature.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.