Select the diamagnetic coloured compound:

The metal ion whose electronic configuration is not affected by the nature of the ligand and which gives a violet colour in non-luminous flame under hot condition in borax bead test is

$[Co(NH_3)Cl(en)_2]^{2+}$ shows two geometrical isomers,$cis$ and $trans$. Which of the following statements is correct?

Which one of the following coordination complexes exhibits the lowest value of magnetic moment (in $BM$)?

What will be the theoretical value of magnetic moment $(\mu)$ when $CN^-$ ligands join $Fe^{3+}$ ion to yield a complex (in $BM$)?

Which of the following is true for $[Fe(CN)_6]^{3-}$ and $[FeF_6]^{3-}$?