Question

The complex that can show optical activity

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• A. $trans-\left[Fe\right(N{H}_3{)}_2(CN{)}_4{]}^{-}$
• B. $trans-\left[Cr\right(C{l}_2\left)\right(ox{)}_2{]}^{3-}$
• C. $cis-\left[CrC{l}_2\right(ox{)}_2{]}^{3-}(ox=oxalate)$
• D. $cis-\left[Fe\right(N{H}_3{)}_2(CN{)}_4{]}^{-}$

Answer 1

The correct option is C $cis-\left[CrC{l}_2\right(ox{)}_2{]}^{3-}(ox=oxalate)$

When the oxalate groups are arrangement in cis position, there are in different planes and it does have a plane of symmetry. Hence, $cis-\left[CrC{l}_2\right(ox{)}_2{]}^{3-}$ is optically active.
Cis and trans form of $\left[Fe\right(N{H}_3{)}_2(CN{)}_4{]}^{-}$ and $trans-\left[Cr\right(C{l}_2\left)\right(ox{)}_2{]}^{3-}$ have plane of symmetry so these compounds are optically inactive.

Hence, option (d) is correct.