Question

Which of the following statements is not true about the complex ion, $\left[CrCl\right(N{O}_2\left)\right(en{)}_2{]}^{+}$?
(en = enthylene diamine)

• A. It has two geometrical isomers-cis and trans
• B. Cis and trans forms are not diastereomers to each other
• C. Only the cis isomer displays optical activity
• D. It has three optically active isomers: $d,l$ and meso form

Answer 1

Answer: (B), (D)

It has three optically active isomers: $d,l$ and meso form


(a) Two geometrical isomers are possible for the complex $\left[CrCl\right(N{O}_2\left)\right(en{)}_2{]}^{+}$.
Thus, statement (a) is true.

(b) Cis and trans forms are diastereomers to each other. Thus, statement (b) is not true.

(c) Only the cis isomers display optical activity. Whereas trans isomer is optically inactive due to plane of symmetry.
Thus, statement (c) is true.

(d) It has total of three isomers. Cis isomer has two optically active isomers: d, l form. The trans form is optically inactive.
Thus, statement (d) is not true.