Select the correct statement

Options

A. Chelation effect is maximum for five and six membered rings
B. Greater the charge on the central metal cation, greater the value of `Delta` (CFSE)
C. In complex ion `[CoF_(6)]^(3-),F^(-)` is a weak field ligand, so that `Delta_(oct)ltP` (Pairing energy) and it is low spin complex
D. `[CoCl_(2)(NH_(3))_(2)(en)]^(+)` comples ion will have four different isomers.

Answer

A, B, D

Explanation

small rings result in angle strain
b) crystal field splitting `alpha` charge of metal ion. For 3d-series elements CFSE is 50% higher for `M^(3+)` ions than for `M^(2+)` ions.
c) Week ligand fields cause high spin complexes.
d)