For octahedral Mn(II) and tetrahedral Ni(II) complexes, consider the following statements:

(I) both the complexes can be high spin.
(II) Ni(II) complex can very rarely be low spin.
(III) with strong field ligands, Mn(II) complexes can be low spin.
(IV)aqueous solution of Mn(II) ions is yellow in colour.

The correct statements are :

The isomer(s) of [Co(NH₃)₄Cl₂] that has/have a Cl–Co–Cl angle of 90°, is/are :

The correct order of the spin-only magnetic moments of the following complexes is :
(I) [Cr(H₂O)₆]Br₂
(II) Na₄[Fe(CN)₆]
(III) Na₃[Fe(C₂O₄)₃] ($$\Delta $$₀ $$>$$ P)
(IV) (Et₄N)₂[CoCl₄]

Complex X of composition Cr(H₂O)₆Cl_n has a spin only magnetic moment of 3.83 BM. It reacts with AgNO₃ and shows geometrical isomerism. The IUPAC nomenclature of X is :