Question

Compound that is both paramagnetic and coloured is:

• A. $K_{2}C{r}_2{O}_7$
• B. $\left(N{H}_4{)}_2\right[TiC{I}_6]$
• C. $VOS{O}_4$
• D. $K_3\left[Cu\right(CN{)}_4]$

Answer 1

Answer: (C)

$VOS{O}_4$

In VOSO${}_4$ we have no VO${}^{+}$ ion in which oxidation state of V is +3.

So, the electronic configuration for $V^{3+}$ is [Ar] 3d${}^{2}4s^0$ because of presence of 2 unpaired e${}^{-}$s it is paramagnetic and coloured as well.

K${}_{2}C{r}_2{O}_7$ - diamagnetic -orange

(NH${}_4{)}_2$[TiCl${}_6$]- diamagnetic - colourless

$K_3\left[Cu\right(CN{)}_4$] - diamagnetic- colourless.