Question

Number of stereoisomers possible for the complexes, $\left[\mathrm{CrCl}_{3}(\mathrm{py})_{3}\right]$ and $\left[\mathrm{CrCl}_{2}(\mathrm{ox})_{2}\right]^{3-}$ are respectively} (py = pyridine, ox = oxalate)

• A. $3 \& 3$
• B. $2 \& 2$
• C. $2 \& 3$
• D. $1 \& 2$

Hint:

Stereoisomers include geometrical and optical isomers.

Answer 1

The Correct Option is C

1. $\left[\mathrm{CrCl}_{3}(\mathrm{py})_{3}\right]$: - Facial and meridional isomers are possible. - Total stereoisomers = 2. 
2. $\left[\mathrm{CrCl}_{2}(\mathrm{ox})_{2}\right]^{3-}$: 
- Geometrical isomers: cis and trans. 
- Optical isomers for cis: 2. 
- Optical isomers for trans: 1. 
- Total stereoisomers = 3. 
Therefore, the correct answer is (3) 2 & 3.