Question: The complex that can show optical activity i
trans- $\left[\mathrm{Cr}\left(\mathrm{Cl}_{2}\right)(\mathrm{ox})_{2}\right]^{3-}$
trans- $\left[\mathrm{Fe}\left(\mathrm{NH}_{3}\right)_{2}(\mathrm{CN})_{4}\right]^{-}$
$c i s-\left[\mathrm{Fe}\left(\mathrm{NH}_{3}\right)_{2}(\mathrm{CN})_{4}\right]^{-}$
cis- $\left[\mathrm{CrCl}_{2}(\mathrm{ox})_{2}\right]^{3-}(\mathrm{ox}=$ oxalate $)$
Correct Option: , 4
Solution:
Only cis- $\left[\mathrm{CrCl}_{2} \text { (ox) }_{2}\right]^{3-}$ shows optical isomerism while its trans form do not show optical isomerism due to presence of plane of symmetry.