Consider the following statements for octahedral complexes. (a) $\left[\mathrm{CrF}_{6}\right]^{3-}$ (b) $\left[\mathrm{Cr}(\mathrm{ox})_{3}\right]^{3-}$ and (c) $\left[\mathrm{Cr}(\mathrm{en})_{3}\right]^{3+}$A. their $d \rightarrow d$ transitions are at 14900, 17500, and $21800\ \mathrm{cm}^{-1}$, respectivelyB. their spin-only magnetic moments are sameC. two of them have optical isomersD. all of them show Jahn-Teller distortionThe correct statements are
(c)B, C, and D
(a)A, B, and C
(b)A, C, and D
(d)B and D
Answer
Answer: A ✓ checked by 4AB · confidence high
Explanation
All three are Cr(III) d³. Field strength rises F⁻ < ox < en, which matches 14900 < 17500 < 21800 cm⁻¹. All have 3 unpaired electrons. The two chelates are chiral, and d³ shows no Jahn–Teller distortion. A, B and C (a).