The correct order of $\left[\mathrm{FeF}_6\right]^{3-},\left[\mathrm{CoF}_6\right]^{3-},\left[\mathrm{Ni}(\mathrm{CO})_4\right]$ and $\left[\mathrm{Ni}(\mathrm{CN})_4\right]^{2-}$ complex species based on the number of unpaired electrons present is:

Which one of the following complexes will have $\Delta_{\mathrm{o}}=0$ and $\mu=5.96$ B.M?

Number of stereoisomers possible for the complexes, $\left[\mathrm{CrCl}_3(\mathrm{py})_3\right]$ and $\left[\mathrm{CrCl}_2(\mathrm{ox})_2\right]^{3-}$ are respectively $(p y=$ pyridine,$o x=$ oxalate $)$

Identify the diamagnetic octahedral complex ions from below ;

A. $\left[\mathrm{Mn}(\mathrm{CN})_6\right]^{3-}$

B. $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$

C. $\left[\mathrm{Fe}(\mathrm{CN})_6\right]^{4-}$

D. $\left[\mathrm{Co}\left(\mathrm{H}_2 \mathrm{O}\right)_3 \mathrm{~F}_3\right]$

Choose the correct answer from the options given below: