Question

Assertion : $\left[ Co \left( NO _{2}\right)_{3}\left( NH _{3}\right)_{3}\right]$ does not show optical isomerism.
Reason : It has a plane of symmetry.

• A. If both assertion and reason are true and reason is the correct explanation of the assertion
• B. If both assertion and reason are true but reason is not the correct explanation of the assertion
• C. If assertion is true, but reason is false
• D. Both assertion and reason are false statements

Answer 1

Answer: (A)

Optical isomerism is due to the absence of elements of symmetry, i.e., plane of symmetry, axis of symmetry or centre of symmetry in complex. If the molecules possess any of these elements of symmetry, the compound will not be optically active $\left[ Co \left( NO _{2}\right)_{3}\left( NH _{3}\right)_{3}\right]$ possesses a plane of symmetry and can superimposed on its mirror image, so it is not an optically active complex.