Question:
Indicate the complex/complex ion which did not show any geometrical isomerism :
Correct Option: 2
Solution:
(1) $\left[\mathrm{CoCl}_{2}(\mathrm{en})_{2}\right]$ show
Cis-trans isomerism
(2) $\left[\mathrm{Co}(\mathrm{CN})_{5}(\mathrm{NC})\right]^{-3}$ can't
Show G.I.
(3) $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{3}\left(\mathrm{NO}_{2}\right)_{3}\right]$
Show fac \& mer isomerism
(4) $\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{4} \mathrm{Cl}_{2}\right]^{\oplus}$ show cis \& trans isomerism