Question

Find out the wrong statement for an octahedral complex:

• A. An ion with $d^6$ configuration is diamagnetic in presence of strong field ligand
• B. An ion with $d^5$ configuration has one unpaired electron both in weak and strong fields
• C. A central metal ion with $d^8$ configuration has two unpaired electrons irespective of the nature of the ligand
• D. In $d^4,d^5,d^6\text{and}{d}^7$ configuration, metal ions have different number of unpaired electrons in presence of weak and strong field ligands respectively

Answer 1

The correct option is B An ion with $d^5$ configuration has one unpaired electron both in weak and strong fields

(A) $d^5$ configuration isWith strong field ligand, pairing will take place and number of unpaired electrons will become $1$
With weak field ligand, electrons does not get paired and number of unpaired electrons will be $5$
(B) $d^8$ configurationSo in case of $d^8$ configuration, number of unpaired electrons in presence of both strong field and weak field ligand is same only, which is $2$
(C) $d^6$ configuration isIn case of $d^6$ configuration in presence of strong field ligand pairing will occur and the number of unpaired electrons will be $0$
Therefore, it show diamagnetic nature.
(D) In $d^4$ electronic configuration, the number of unpaired electrons in presence of weak field ligand is $4$ and in presence of strong field ligand it is $2$
In $d^5$ electronic configuration, the number of unpaired electrons in presence of weak field ligand is $5$ and in presence of strong field ligand it is $1$
In $d^6$ electronic configuration, the number of unpaired electrons in presence of weak field ligand is $4$ and in presence of strong field ligand it is $0$
In $d^7$ electronic configuration, the number of unpaired electrons in presence of weak field ligand is $3$ and in presence of strong field ligand it is $1$