Consider following statements regarding the magnetic moment of the 3d transition metal complexes:

A. Octahedral complexes of $$Mn^{II}$$​  (high spin) and $$Fe^{III}$$ (high spin) have $$\mu_{eff}$$ approximately equal to their $$\mu_{spin}$$ values.​

B. Tetrahedral complexes of $$Ni^{II}$$ and octahedral complexes of $$Co^{II}$$​ have orbital contribution added to their magnetic moments.

C. Orbital contribution is quenched for metal ions having A or E ground state.

D. Octahedral complexes of $$Cu^{II}$$ have $$\mu_{eff} > \mu_{spin}$$ value at 300 K due to orbital contribution added to their magnetic moments​

Choose the correct answer from the options given below:

The possible terms arising from a p¹d¹ configuration are

For octahedral geometry the triad with no net gain in CFSE, when the ligand field changes from weak to strong, is:

The correct statement for the CO and $$N_2$$ ligands in the complexes trans – $$[lrCl(CO)(PPh_3)_2]$$ and $$tranws-[lrCl(N_2)(PPh_3)_2]$$ is:​

The correct pair among the following, in which each species shows orbital contribution to its magnetic moment is

The red colour of the gem, ruby is predominantly due to

​$$\text{The rate of hydration of } [\text{Cr}^{\text{III}}(\text{H}_2\text{O})_5X]^{n+} \, (\text{X = N}_3^-, \, \text{F}^-, \, \text{CN}^-, \text{ and NH}_3) \text{ in neutral aqueous medium} \\\text{remains unaffected in acidic medium at room temperature, if ‘X’ is}$$​​

​The value of magnetic moment will be independent of temperature for​

(acac=acetylacetonato; OAc=acetate; o-phen=o-phenanthroline; Pz=pyrazolyl)

The number of expected electronic transitions in [Cr(en)₃]³⁺ and trans-[Cr(en)₂F₂]⁺ at 4 K is, respectively (en=ethylenediamine)

​

The products A and B for the given reaction 

​are, respectively

​