Chemistry - Complete d-block Question with Solution | TestHub

(d) $\mathrm{In}{\mathrm{K}}_4\left[\mathrm{Fe}(\mathrm{CN}{)}_6\right]\mathrm{Cu}$ is in $+1$ oxidation state hence has no unpaired electron hence colourless and diamagnetic. (b) $\mathrm{In}{\left({\mathrm{NH}}_4\right)}_2\left[{\mathrm{TiCl}}_6\right]\mathrm{Ti}$ is in $+4$ oxidation state. hence has no unpaired electron hence colourless and diamagnetic. (c) $\mathrm{In}{\mathrm{VOSO}}_4,V$ is in $+4$ oxidation state hence has one unpaired electron, thus it is coloured and paramagnetic. (a) $\mathrm{In}{\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$, Cr is in $+6$ oxidation. hence has no unpaired electron and thus it is diamagnetic. Though ${\mathrm{K}}_2{\mathrm{Cr}}_2{\mathrm{O}}_7$ has no unpaired electron but it is coloured. This is due to charge transfer spectrum.