Question

Among the following compounds which is both paramagnetic and coloured?

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

Answer 1

Answer: (B)

$\left[Co\right(S{O}_4\left)\right]$

$Co\left(S{O}_4\right)\Rightarrow C{o}^{2+}\to \left[Ar\right]3d^7$

1. Paramagnetic.

2. And it is has red colour due to its unpaired electrons.