Question

Which of the following does not show optical isomerism?

• A. Cis-[CrCl$_2$(C$_2$O$_4$)$_2$]$^{3-}$
• B. [PtCl$_2$(en)$_2$]$^{2+}$
• C. [Co(NH$_3$)$_3$(NO$_2$)$_3$]
• D. [Co(en)$_3$]$^{3+}$

Hint:

Optical isomerism occurs when a molecule lacks a plane of symmetry and can exist in non-superimposable mirror images.

Answer 1

The Correct Option is C

Step 1: Checking for optical isomerism. 
- Optical isomerism occurs in complexes with chiral centers or asymmetric arrangements. 
- Cis-[CrCl$_2$(C$_2$O$_4$)$_2$]$^{3-}$ can show optical isomerism due to asymmetric bidentate ligands. 
- [PtCl$_2$(en)$_2$]$^{2+}$ and [Co(en)$_3$]$^{3+}$ also show optical isomerism. 
- [Co(NH$_3$)$_3$(NO$_2$)$_3$] lacks asymmetry and does not exhibit optical isomerism.