Number of stereoisomers possible for the complexes, [CrCl3(py)3] and [CrCl2(ox)2]3- are respectively (py = pyridine, ox = oxalate)
- 3 & 3
- 2 & 3
- 1 & 2
- 2 & 2
Answer
(2) 2 & 3
Solution
[CrCl3(py)3] is of the type [MA3B3]: it shows fac and mer geometrical isomers. Both have a plane of symmetry, so neither is optically active, which gives 2 stereoisomers.
[CrCl2(ox)2]3- is of the type [M(AA)2B2] (like [CoCl2(en)2]+ in NCERT): the trans form is optically inactive, while the cis form is chiral and exists as a pair of enantiomers (d and l), so there are 1 (trans) + 2 (cis-d, cis-l) = 3 stereoisomers.
Answer: (2)