Question

Assertion : Complexes of $\left[M{X}_6\right]$ and $\left[M{X}_5\right]$ type (X and L are unidentate) do not show geometrical isomerism.

Reason : Geometrical isomerism is not shown by complexes of coordination number [Equation]

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

Answer 1

The correct option is B Assertion is true, reason is false.

Assertion:

In $M{X}_6\&M{X}_5$ complexes there are four ligands in the same plane and all are identical ligands linked to the metal atom, so they don't show geometrical isomerism.

Thus, the assertion statement is correct.

Reason:

In reason it is given that complexes with coordination number 6 will not show geometrical isomerism. Reason is wrong here as compounds with coordination number 6 have octahedral geometry and they can show geometrical isomerism. 

So, the reason is false.

Hence, assertion is true but reason is false.